I was wondering if you guys had done this mod to your truck and if so did you put new shocks on the front. I have heard that you did have to and also heard that you didnt. Thanks

If you search for this you can find a lot. Many guys put new shocks on, some spaced the stock shocks up. Depends if you want to buy new shocks right away. You need to do something because they can overextend when you flex it and snap. Also you can snap the sway bar end links too. I did both on my 2000 1/2 ton. Then I put new end links and rancho RSX shocks on it and it was good after that.

OffRoadUnlimited.com sells a kit--

<TABLE cellSpacing=0 cellPadding=0 width="100%" border=0><TBODY><TR><TD><TABLE cellSpacing=0 cellPadding=0 width="100%" border=0><TBODY><TR><TD class=pageHeading vAlign=top>Chevy/GMC Leveling Cog and Shock Kit
[60007BIL]</TD><TD class=pageHeading vAlign=top align=right>$389.99</TD></TR></TBODY></TABLE></TD></TR><TR><TD>http://www.offroadunlimited.com/store/images/pixel_trans.gif</TD></TR><TR><TD class=main><TABLE cellSpacing=0 cellPadding=2 align=right border=0><TBODY><TR><TD class=smallText align=middle><SCRIPT language=javascript><!--document.write('images/60007bil_large.jpg
Click to enlarge (javascript:popupWindow('http://www.offroadunlimited.com/store/popup_image.php?pID=189'))');//--></SCRIPT>http://www.offroadunlimited.com/store/images/60007bil_large.jpg
Click to enlarge (javascript:popupWindow('http://www.offroadunlimited.com/store/popup_image.php?pID=189')) <NOSCRIPT>images/60007bil_large.jpg
Click to enlarge (http://www.offroadunlimited.com/store/images/60007bil_large.jpg)</NOSCRIPT></TD></TR></TBODY></TABLE>2500 HD 2" Leveling Cogs and Shock Kit The ORU HD leveling kit is the proper way to level your trucks factory height without overloading the torsion bars, which causes a harsh ride and accelerated front end wear. These cogs level the truck, allowing the installation of 33” tires. Installation must be accompanied by a professional alignment. This special includes 4 Bilstein 5100 series shocks.

</TD></TR></TBODY></TABLE>

Click here to see the article in Petersen's 4Wheel & Off-Road magazine (http://www.offroadunlimited.com/new/articles/petersens/4wheel_article.html)




<!-- ImageReady Slices (4wheel_article.jpg) --> <TABLE id=Table_01 height=1011 cellSpacing=0 cellPadding=0 width=731 border=0><TBODY><TR><TD colSpan=8>http://www.offroadunlimited.com/new/articles/petersens/images/4wheel_article_01.gif</TD><TD rowSpan=10>http://www.offroadunlimited.com/new/articles/petersens/images/4wheel_article_02.gif</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD></TR><TR><TD rowSpan=9>http://www.offroadunlimited.com/new/articles/petersens/images/4wheel_article_03.gif</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/4wheel_article_04.jpg</TD><TD rowSpan=6>http://www.offroadunlimited.com/new/articles/petersens/images/4wheel_article_05.gif</TD><TD vAlign=top colSpan=5 rowSpan=2>IFS
LEVELING
KIT
</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD></TR><TR><TD vAlign=top rowSpan=7>

BY David Kennedy PHOTOGRAPHY
DAVID KENNEDY One of the most common questions readers ask us is, ”How big of a tire can I fit on my truck without lifting it?” The size we have to quote is usually much smaller than people want to hear, so we also try to recommend an inexpensive way for them to fit 33s. So if you drive an ’01 or newer GM 2500HD here’s a good setup for you. For $69 (plus $160 for the recommended Bilstein 5100 series shocks) you can order Off Road Unlimited’s HD leveling kit to raise the front of your GM truck 2 inches and clear most 33-inch tires. The ORU HD leveling kit is basically two new torsion-bar keys that come with a different clocking for the key’s hex. The new keys (top) are made to the same top quality standards as the stock pieces (lower) and provide up to 2 inches of lift for the front suspension.

</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD></TR><TR><TD colSpan=5>http://www.offroadunlimited.com/new/articles/petersens/images/4wheel_article_08.gif</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD></TR><TR><TD colSpan=3 rowSpan=3>http://www.offroadunlimited.com/new/articles/petersens/images/4wheel_article_09.jpg</TD><TD rowSpan=3>http://www.offroadunlimited.com/new/articles/petersens/images/4wheel_article_10.gif</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/4wheel_article_11.jpg</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD></TR><TR><TD>http://www.offroadunlimited.com/new/articles/petersens/images/4wheel_article_12.gif</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD></TR><TR><TD>http://www.offroadunlimited.com/new/articles/petersens/images/4wheel_article_13.jpg</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD></TR><TR><TD colSpan=6>http://www.offroadunlimited.com/new/articles/petersens/images/4wheel_article_14.gif</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD></TR><TR><TD colSpan=2>http://www.offroadunlimited.com/new/articles/petersens/images/4wheel_article_15.gif</TD><TD rowSpan=2>http://www.offroadunlimited.com/new/articles/petersens/images/4wheel_article_16.gif</TD><TD colSpan=3 rowSpan=2>http://www.offroadunlimited.com/new/articles/petersens/images/4wheel_article_17.jpg</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD></TR><TR><TD vAlign=top colSpan=3>1 Installation is straight forward. Raise the truck off the ground and support it with jackstands. Use a ball-joint press or GM J-tool (PN J36202) to unload the torsion bars safely and remove the adjuster bolts and nuts. Slowly release the torsion-bar preload with the ball-joint press or the J-tool and remove the torsion bars. At ORU the technicians drive the torsion bars forward with a punch to break them free of the keys if the truck has a lot of rust under it. 2 To compensate for the increased ride height you will need to bolt on a set of longer shocks. Off Road Unlimited has found the best ride and handeling combination by using Bilstein’s 5100 series shocks (PN 60007-B). Installing these gas monotube shocks is much easier with the truck off the ground and the front suspension at full drop. 3 The finished product sits approximately 2 inches higher than the stock truck did up front. That’s enough room to run 285/75-16 tires on the stock wheels. Keep in mind that anytime you alter the ride height of an IFS truck you need to have the front end professionally aligned for proper handeling and tire wear. </TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD></TR><TR><TD colSpan=9>http://www.offroadunlimited.com/new/articles/petersens/images/4wheel_article_19.gif</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD></TR><TR><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD><TD>http://www.offroadunlimited.com/new/articles/petersens/images/spacer.gif</TD><TD></TD></TR></TBODY></TABLE><!-- End ImageReady Slices -->

Looks like there is still the same misunderstanding about green keys, levelling kits, levelling cogs....you name it! The adjustment with the original keys does EXACTLY the same thing then any aftermarket product - increasing the tension on the torsion bars to gain a lift. The difference is only that those original keys might not be adjustable far enough to lift the truck full 2 inches....Harsh ride quality, stress on the components etc. will be exactly the same whatever key is used - as long the adjusted lift height is the same than with the original keys. The higher the lift the worst it will be, there is no doubt about that!

Just got my 05, Had crome H2's, 285 BFG's, green keys and rancho 9000's four weeks before my truck shoed up. Installed everything in about 3 hours, never doing it before. Took advice from the gm-tech note and bought the torsion bar unloading tool. After doing the key's I would highly recommend not trying this unless you have the tool. The min lift with the keys is 2", I only wanted about 1 3/4" so in hind site you could probable get that with out the keys. I like the fact that they are not putting all of that load on an extended cantalevered bolt. trimed the front air dam and a little off the plastic wheel under the window washer bottle. truck ride so much better than stock, you don't have that wishy washy front end feel. Tighter more aggressive feel but nice and smooth over choppy stuff. I have 1.5" block kit on order from superlift and will be doing the rear with rancho's when it shows up.

I also just installed 4 infinity kappa 62.5 speakers and have an infinity basslink still to go. Got my truck tree days ago !!

Since the question was if people who have used the green keys swapped for longer shocks or not I will say I have been running them in mine for 2 yrs now lifted 2" and never replaced the shocks. From the sounds of people who have swapped them it does sound like you will get positive results. Keep in mind that doing this mod does not mean you have a lift kit and can start doing some serious off roading now. For street use there is nothing wrong with way and you will not wear out your parts in a heartbeat either. Get a good suspension lift if you intend on off roading.

The keys DO make a difference in ride over just cranking your stocker because the offset basically adjusts your ride height before you start addind the tension to the torsion bar and that is it. they do not just allow for more adjustment to crank farther or and more tension to the torsion bars. they just adjust your ride in the front. I have tested both set ups side by side and yes there is a noticable difference in ride. With the keys is about equal to 3-4 cranks on your stock bars but no where near the harshness of fully cranked stock keys. Good luck with them and keep in mind that if you don't like the result you can alway put it right back where it was as long as you take measurements before you start.

So where can we get the keys? How much for them, and what about the Blistens? Price for them in general?

I have installed keyways in my truck and I would never do it again, save up for a real lift kit. Just trust me, you will spend more money in worn out parts than just installing a real lift.

How exactly can keys increase ride height without loading torsion bars? really?

It doesn't make sense. Unless someone can clearly explain it to me I am in agreement with mahalkita, the new keys (see picture) simply start with more torsion bar preload , as seen by angle of cog relative to the centerline of each key.

Either this isn't rocket science, or .... it is, and I'm missing the boat.

Mahalkita is right, keys only index the bars at a different point, basically start with a bit more preload than stock if you have the bolt in the same thread position. Thats it, no magic pill, thats all they do. I saved the money on the keys and ran my bolt in. Made my own TBar unloading tool out of the parts from 2 different gear pullers and some scrap steel. You cannot change the ride characteristics unless you change the Tbars themselves.

You can't increase the torque on the bars without increasing the weight or resistance. the weight of the truck is the resistance and does not change. If you put the keys in you will see that the front suspension drops before the torquing of the bars begin. Because you are not putting more force on the oppisite end you are not increasing the torque. It has to take the path of least resistance and that is the suspension dropping therefore lifting the truck.

Again you really should not be off roading or you will most likely damage parts but simple highway driving is NOT going to cause you to wear out parts.

Heh heh "The new keys (top) are made to the same top quality standards as the stock pieces (lower)"
Of course because they look just like the green keys many guys have that came from a 1/2 ton pickup.. SO yeah I'm sure they are the same quality as the stock parts. (wink wink) Cheaper from gm too I think. I kept mine from my old truck since I had put different ones on it for lift. They are still sitting in my toolbox. Haven't installed them yet because the 285s fit fine and I want to wait and buy shocks.
It is true that this will increase angles and cause parts to maybe wear faster/break more, but have you seen a picture of a rancho or rcd lift when it's at full droop? The a-arm hangs really low and makes harsh cv angles too, so really anything other than stock is going to change how components wear. Most guys just figure it's worth it for the higher stance and better tire clearance. Basically you just need to decide if it's worth it for you...

You can't increase the torque on the bars without increasing the weight or resistance. the weight of the truck is the resistance and does not change. If you put the keys in you will see that the front suspension drops before the torquing of the bars begin. Because you are not putting more force on the oppisite end you are not increasing the torque. It has to take the path of least resistance and that is the suspension dropping therefore lifting the truck.

Again you really should not be off roading or you will most likely damage parts but simple highway driving is NOT going to cause you to wear out parts.Hmm? I fully understand this principle, and in theory it makes sense, but... Where the principle assumptions fails is:

1. With the keys put on the bar and the suspension lowered there is no torque on the bar). That's true. BUT! we don't drive with the keys "just in" we have to turn the keys with a tool until we can get them at least over the key stop. = LOAD. So, at miminum (funtional) key rotation there is still a load on the bar, otherwise we wouldn't need a tool. If there is load with a stock key there is MORE load with a green key. More load = higher ride hight = stiffer ride (which some people like, including myself, although I can barely tell the difference..)

I've been wrong before so I'll keep thinking about it "physics is fun".

thanks for the thought 03GMC2500HD,

Caswell

Ok, I'll try to explain it again.

The "green keys" re-index the springs so that they continue to operate in their intended range (regarding overall motion). They do this while increasing the distance between 'sprung' & 'unsprung' weight. By simply cranking up the stock keys all you are doing is creating a larger range of operation & forcing the springs to function (the majority of the time) at the upper end of their intended range.

Think of it this way, if 0-100 (it's just a #) is your springs operating range, around 50 would be the optimum 'rest' point (loaded) as it allows you equal distances between minimum & maximum thereby permiting full rebounding opportunities (both up & down-that's what their responsible for) for the spring. If you were to simply move your stock keys 'resting' point up to 75 (+1.5") by cranking them up, you would lose at least 50% of your springs intended operational ability (25 above & 25 below). Also, by forcing the springs to operate at their upper ranges, rebound tensions increase & deflection rates go up. In other words, this causes the springs to react quicker/harder then their design intended which negatively impacts ride quality (in increasing proportion related directly to the amount of operating range 'lost'). Simply put, you would not only be limiting the springs effective "area of operation", but you would also be operating the springs "out of range".

However, if you were to re-index the springs via different keys (ei-alter their 'installed' height), the springs would lose nothing in regards to 'operational flex'. The only change would be a difference in sprung to unsprung clearance.
If the value of 'sprung' weight (which is what springs support) is 4 tons with 30" of clearance (rim to fender edge), it is still 4 tons at 32" of clearance, the vehicle doesn't suddenly weigh more because you've increased it's height/clearance - & springs are rated for weight (actually, it probably weighs a few nanograms less due to the diminished effects of gravity at increased altitude, not to mention less atmosheric pressures-ie-less air weight, but i'll let you physics professors out there explain that-ha,ha,just kidding).
Re-indexing torsion bars is no different than placing a block under coil springs (ie-between sprung & unsprung weight) to gain height/distance, it simply moves the point at which unsprung weight begins its commitment to sprung weight. What effect would that have on coil springs (or any springs for that matter)? they would still carry the same weight, have the same 'installed height', & the same range of operation. The vehicles rise would simply reflect the differences of distance between having a block, & not having a block. Other than some minor geometry increases (& a slight 'center of gravity' rise), nothing changes.

Yes you do need to "re-index" your shocks (as they control spring oscillation) when you increase sprung to unsprung distances so that they too remain in proper operating range (& avoid possible damage). Usually 1" of washers added underneath the upper mount will do for 2" of overall rise (as the front shocks sit inboard & at an angle, you do not need to match the difference to overall lift).
In regards to accelerated wear in parts due to increased angles, well, I've never seen 1-3" have that great an impact in a truck. Anything more though & you may be asking for trouble.

If you want to add some height (+1" to 3"max) while maintaining a 'similar to stock' degree of ride quality regarding springs;
Green keys (ie-indexing the spring) are the way to go.

Hope this helps folks understand better :D

Loki_nine,

Nice explanation. The only thing I don't agree with is your statement that Green keys are the way to go. . . If you can get the +1 to 3" max on the stock keys, no need to go with Greens. . .

Dennis

Loki_nine,
your explanation is definitely WRONG! Whatever keys you use you are doing the EXACT same thing - increase torsion on the bars to lift the frontend of the truck. There is NO reindexing done with any kind of key, that physically impossible. All you do is twisting the bars to a higher degree with green keys than with stock keys because the lever has another angle compared to stock (assuming you turn the set screw the same amount than with the stock key). Therefore you can lift the truck higher with the green key. But only by twisting the torsion bars more you can lift the truck higher. All the disadvantages (load to the bars, suspension etc.) apply with any kind of key. The opposite is true with a lowering key, you twist the bar just in opposite direction than stock - still with the same problems...

Sounds to me like you guys are saying the same thing with different words.

another look...

If you add longer spring shackles to a leaf spring set-up then you would in fact raise the ride height without changing the spring rate.
But with the torsion bar set-up the only way to increase ride height is to "twist" the bars more. The bar is a rotational spring. True you are not increasing the weight of the front of the truck, you will have to add more "spring tension" to raise it higher, hence more rotation. Adding a block under a coil spring will add ride height without changing spring rate.

One other thing...

If you were to "re-key" or re-index the front of the torsion in relation to it's mounting rotation, then you would in fact increase ride height without changing the spring rate. but if you are adding more twist as in re-keying the back, then you increasing the bar's spring rate.
Pete

Testing...testing...is this thing on?

You CAN NOT put more twist in the bar without more resistance on the oppisite end. The resistance (force) on the oppisite end does not change. If the suspension limits were bottomed out and resting on a bump stop or something then yes there would be more twist but you would have no gain. When you install the keys you are not cranking the bars to get them in place but actually the suspension is dropping before you get the TB torqued because the resistance on the front end is the same and that is the path of least resistance for the suspension. It has no choice but to drop not stay in the same place and let the TB twist.

Crank the snot out of your stock keys for 2" of lift, which I doubt you could get over 1.5"-1.75" max anyway, then install the other keys and go 2" and then you will see the difference. I know it doesn't sound right but until you try it how do you really know?

Granted the "green keys" are not the best way to go compared to a suspension lift but if you do not like the looks of a BL and you are mainly highway driving then it is the most economical way to go.

Trying to make this simple...

Twisting the torsion bar lifts the truck regardless of which key you use. One key will need the bolt run up more or less but the torsion bar is doing the same thing with either key.

O/K, let me see if I can get someone else to explain it better.
Here's an article from "Petersons 4Wheel & Off-Road"

__________________________________________________ __________

Torsion-Bar Tech

Basic Info on the Most Simple of All Springs<O:p</O:p

By David Kennedy<O:p</O:p

We wish we could tell you that torsion-bar springs are modern technology's answer to the quest for soft riding, long travel, and easily modified suspensions. When we were researching this story we hoped that we would stumble across some tech tidbit that would open the door to some unexplored applications for these straightened-out coil springs to give you new alternatives to the leaves and coils. We're sad to say it seems we need to keep looking. "Basic" and "off-road use" go hand-in-hand. Of all the types of springs you can find on a 4x4 the torsion bar uses the most basic design. Throw in the fact that our country's M1A1 Abrams battle tanks use torsion-bar suspension and they start to sound like the perfect spring for off-road use don't they?
Unfortunately the reality is that this simple spring design has been great for the original equipment manufacturers (OEMs), but has left us in the aftermarket with 4x4s that are more difficult and more expensive than ever to lift. For now the only correct way to lift a torsion-bar-sprung independent-suspension 4x4 is to drop all of the suspension locating points down to gain lift, sort of like adding longer shackles to leaf-spring suspensions. The upside is that when lifted this way a torsion-bar-equipped truck can maintain a stock ride quality. The down side is that it is almost impossible to get additional travel out of this kind of suspension. If you're starting to feel discouraged about owning a torsion-bar-outfitted truck, fear not! We'll keep investigating options for torsion-bar suspensions until we find something that makes them work better than the other spring options out there.Torsion-bar suspensions do have some drawbacks. The biggest problem we see is that it is almost impossible to have a progressive-rate torsion bar. Some OEMs have compensated for this by designing the suspension to ride on jounce bumpers (don't call them bumpstops!) to effectively get a progressive spring rate at the wheel. But this still leaves the problem torsion bars have of limiting the amount of compliance that can be designed into the suspension. Compliance is a term used by suspension engineers to describe the up-and-to-the-rear path the tire should ideally take as the suspension compresses. A torsion bar will not permit this complex suspension motion without buckling the bar.

(Lots of people ask us if they can crank their torsion bars up to lift the front of a 4x4 without buying an expensive lift kit. The answer is yes, but doing so has its downsides and you're not going to be able to get much lift anyway. The adjuster screws are there to compensate for adding a snowplow, winch, or to restore ride height as the torsion bars relax and sag the suspension. They are not for you to crank in to get the maximum lift height possible. If you do go the poor man's lift route make sure to adjust both sides of the truck to the same height and have the front end professionally aligned afterward.)
__________________________________________________ _____________________________________

Index is a term used to reference a particular point (like an index in a book will tell you were to find a particular item/word)
You "drop the suspension points down" by using keys that are indexed differently (ie-a different starting point with springs). There are many index points on every vehicle made-they involve camshafts, crankshafts, most sensors, many front-ends, & also springs to name just a few. We mechanics (technicians for you sensative types) use indexes everyday to aid in most diagnoses.

Hope this helps clear things up. :)

Just a another quick thought, while going over the previous posts here, it seemed to occur to me that the general thinking here is that a springs primary job is to support the weight of the vehicle.
That is not true.
Bricks, wood blocks, or just about any other sturdy material that takes up space will support the vehicle if thats really all that was needed.
The fact is, springs mainly permit the vehicle to maintain an orderly contact with the continually changing surface underneath by using the sprung weight to force the unsprung weight downward. This is one of the main reasons why installing rims, brake rotors, lower control arms (ie-unsprung items) of less weight is so important to road racers, doing this reduces unsprung weight & lets the vehicle suspension react faster to changing road conditions.
Knowing this, & then thinking from the top-down (sprung to unsprung) instead of from the road up, should help clear things up (including some of the handling issues associated with cranking keys)
Top-down reasoning is also why you'll find the compensator (adjusting bolt) on the sprung side of the vehicle. If springs were there simply to support the vehicles weight, you would find them on the unsprung side.

some of these explanations are hilarious. its simple physics - the only way to acheive more lift is more upward force. the only source of upward force on the front end is the torsion bars. the only way to get more upward force out of them is to twist them more.

03gmc2500hd - if you were right about the path of least resistance stuff and the suspension dropping, then all we would have to do is jack the truck up with the wheels off the ground, let the suspension drop and then it would stay that way when you remove the jack. it just doesnt make sense. your downward force is gravity pulling the weight of the truck. the ONLY way to overcome this is a GREATER force in the opposite direction. to get a greater force from the end of the torsion bars, they MUST be under a greater load. its that simple. no arguments.

the best way to describe what "green keys" do is this: for those who have never looked at the torsion bars, the end is just like a hex bolt. picture putting a wrench at the 3 oclock position and turning it to the 12 oclock position - this is what stock keys do. the green keys that "reindex" simply place the wrench at 5 oclock instead. when you turn the wrench to 12 oclock, you have actually twisted the bolt more than with the stock key. this additional twist is what gives you more lift. you are simply moving your starting point.

THERE IS SIMPLY NO WAY THAT THE GREEN KEYS CAN ACHIEVE MORE LIFT THAN STOCK KEYS WITHOUT PUTTING MORE TWIST INTO THE BARS!!

Testing...testing...is this thing on?

You CAN NOT put more twist in the bar without more resistance on the oppisite end. The resistance (force) on the oppisite end does not change. If the suspension limits were bottomed out and resting on a bump stop or something then yes there would be more twist but you would have no gain. When you install the keys you are not cranking the bars to get them in place but actually the suspension is dropping before you get the TB torqued because the resistance on the front end is the same and that is the path of least resistance for the suspension. It has no choice but to drop not stay in the same place and let the TB twist.
yes you can put more twist in the bar without more resistance. in fact, thats the only way to achieve more lift. since your resistance force does not change, you need a greater force on the other end to achieve lift.

you are claiming the keys do not increase the force in your torsion bars and you state the resistance force does not change. where does the extra lift come from then??

ANYBODY THAT HAS INSTALLED THE GREEN KEYS BY THEMSELVES UNDERSTAND'S THAT THEY ARE JUST CRANKING THE CRAP OUT OF THE TORRSION BAR SAME AS STOCK KEYS BUT WITH MORE RANGE. - I'm Out and Good Night.

Ok...if you jack the truck up you are removing the forces action on the suspension and the suspension drops right? Why did the suspension drop? Because there is less force acting on the torsion bars and it has to take the path of least resistance which is to drop. Not gravity! You can flip the truck over and the suspension will have more droop because there are no forces acting against the torsion bars. They won't fall back into the wheel wells. Back to the jack, all the weight of the truck is now acting on the jack and the wheels are off the ground and no forces acting on the suspension right? OK what happens when you remove the jack? Does the weight of the truck leave when the jack is removed? No the weight is now back acting on the suspension which is exactly the same force you had before and that same weight torques the torsion bars exactly the same way and that is why you end up with the same ride height as you had before you jacked it up.

If you were able to put more twist in the TB then that would have to mean that the force acting in the upward direction, which would be a clockwise direction if you were looking at the LCA from the key end of the TB, would have to be greater than the force on the counter clockwise direction of the key. The only way to increase the upward force would be to add weight or put the LCA against a positive stop. Since neither of those things happen and your forces are the same the more the key is rotated in the CCW direction the LCA has to follow in the CCW direction too therefore giving you the lift.

leftmy8.1 I agree/disagree with you. Yes you are cranking the keys more but watch the suspension as you crank. It drops easily with every crank and when you are installing them you are just cranking them enough to get the keeper in not cranking them to the top of the crossmember like with the stock keys. You get the same lift with just a little less cranking needed therefore they ride just a little better. If you use the GM TB unloading tool is very simple to do. 20 min tops!

A spring is a spring, bada bing bad ding !

You are turning the torrion bar to create X amount of torque.

correct!

It is not about lift, it is about increasing clearances while maintaining the full operational range of the springs as their design intented.
I think we can all agree that by cranking the keys (ie-using the springs) to obtain clearance, you are increasing the force applied (in order to project the mass upwards-against gravity), this moves the springs away from their designed range of operation in most aspects,ie-min to max movement increased-rebounding effeciency reduced-etc-etc... (everything has a range of operation).
By installing keys with a different index, you are simply moving the starting point of the springs, no additional force is applied. This allows the springs to operate in the range that they were intended (designed) to.
Porsche has used torsional suspensions for years with torsion bars splined for indexing purposes. It's not easy calculating the correct torsional spring rates for varying loads. Why "re-invent the wheel" by stretching/altering the springs area of operation (which changes it's operational rate) every time you want to change clearances. Porsches splined bars allow indexing at a more finite level to achieve optimum vehicle handling without interfering with design incorporated spring rates. But hey, what do they know, they only build some of the best production performance vehicles on the planet.
I believe that if the continued perspective is from the bottom - up, the dynamics will never quite be understood (I've taught this stuff -Automotive Engineering that is- to students at a State University 2 nites a week for years)
Most of the responses I read here are intelligent & informative, but some of it really flies in the face of even simple reason. :confused:


PS-the main forces to overcome (regarding vehicle springs) are gravity &, to a very slight degree, atmospheric pressure. Without them, Newtons First Law of Motion regarding "objects in motion continuing in motion unless acted upon by another force" would certainly negate any 'weight' issues.
For objects in an enviroment without gravity, the only 'spring action' that would matter would be the first one. :eek:

Since neither of those things happen and your forces are the same the more the key is rotated in the CCW direction the LCA has to follow in the CCW direction too therefore giving you the lift.<!-- / message --><!-- sig -->you are exactly right in that. thats why i dont understand why you dispute the results. you have to turn the bar more to get the lift, no matter what keys you use.

loki_nine you are talking about the purpose of the torsion bars, we are not. we are simply talking about the result of loading them. its very simple - the only possible way to increase the height of the front end is to increase the load put on the bars. i have 300 engineers in this building that will agree ):h

What are you talking about, you have to crank the crap out of the torsion bar loading tool to get the key stop back in place. Then you back the tool off and with the key resting on key stop there is still alot of torque on the torrsion bar. My was at 2" lift the same amount of torque from the stock keys would have created the same amount of lift with no difference. I'm an engineer and you are making something very simple complecated. You are simply adding preload to a spring, thats it nothing more.

yea, somebody else understands! haha

Since we are now using the engineer card, I am an engineer too, so big deal doesn't mean we are smarter than anyone else does it? When I installed my keys it was very simple and only had to crank on it for the last 1/2" or so before installing the key stop. A little more cranking and I was at 2". Didn't break a sweat using a 3/8" drive rachet. When cranking the stock keys I could only get 1.75" with 8 full turns and that was using a 1/2" breaker bar and filling my shorts from the strain to get it there. Maybe your truck was different as most are

What is making this complicated is everyone trying to put their physics hat on and trying to explain why the ride is a little better with the keys or not. Fact is that when I did the comparison (twice) of each set up (stock keys cranked vs. green keys) that the ride is noticably better with the green keys and that is why they are still in there after 2 yrs. Again it is not the stock ride but it is not the harsh ride of the cranked stock keys either. Actually I don't really care why it works as long as it does in my situation. Crank or dont crank it doesn't really matter. For those that use them and it works for them that is good enough. If it doesn't work for you...too bad!

Well, I had my truck on jacks. The stock keys fell right out and I pulled muscles in both arms cranking on the GM torsion tool trying to get the green keys indexed enough to get the key stop in place. I tried using a 300 FT pound 3/4 craftsman impact and it was not able to turn the bolt. So I had one foor on the side of the truck and two hands on the rachet moving the rachet about 1/4" at a time. If my GM torsion tool would have sliped off it would have blown a hole through the concrete. So when you say that using the green key's allows your torsion spring to operate in the middle of its range vs the staock keys, I really have no idea what your talking about. I have zero turns on the bolts and my torrsion bars are totally loaded.

leftmy8.1
When you compare the stock key to the green key, is the hole that the tb fits into in a different location? Another words is the hole physically lower to the ground? Even if it as little as a 1/4"?

Jesse, not sure, it did not seem like it. Why ?

leftmy8.1

I believe that this is what loki nine is getting at. If the tb is reindexed, moved lower to the ground, then the tb would lift the truck higher with the same amount of torque.

Wow, there are some retarded ideas floating around in here. The ONLY things that could increase the load on the bars are: A) more weight in the truck. B) wider front track width. C) Turning the key so far that the suspension hits the stops, then keep turning the adjuster.
Even though you are turning the keys/bars further, this action is countered by the suspension MOVING. This means that you cannot possibly be putting more stress on the bars, THEY ARE JUST MOVING THE CONTROL ARM! This would be different if the truck were strapped down before you crank, but that isn't the case, is it? Think about it. If you have the same weight on the same spring, then you have the SAME PRELOAD. What does change when the suspension cycles through its motion is the TRACK WIDTH. The further the control arms hang down, the NARROWER the track width. This is why the toe changes so much when the ride height is altered. What does this mean? This means there is a SHORTER LEVER acting against the spring, hence, LESS PRELOAD. This narrower track width is what causes the harsh ride that some feel, coupled with the fact that you can now feel the suspension top out over bumps. The green keys/cranked stock keys are the same thing. If you think there is a difference in ride, it may have something to do with a slightly thinner wallet after being ripped off with the green keys. I may not be an engineer, but I know enough about the laws of physics (that I was taught in the third grade) to call BS!

Although I have a degree in Automotive Engineering (you need one to teach at the college level here), I am not an Engineer by trade. I work where the rubber meets the road.
I was long-winded with my explanation by habit. No one leaves one of my classes (or a job) without a thorough understanding of the issues at hand. I turn out excellent techs both at school & at my shop, & the methods I use are hard to not fall into elsewhere.
No insults were intended.

haneym;
If you read the entire thread, you will see that I answered the question in my first post, the subsequent posts were an explanation in support of my apparently controversial answer.
Besides, how could anyone speak about results without fully understanding the purpose (or operation) ??

leftmy8.1;
When installing the green keys, for ease of install you will need to completely "unload" the front suspension, this includes disconnecting the front shocks.
I use a 2 jaw snap-on puller (but I have also used a ball joint press in a pinch)
Not too much effort is required once you unbolt the shocks allowing the control arm to hang relatively free

jesse;
no, the hole for the torsion bar is "clocked" differently, that is all.

Whewww...glad you were here to clear things up for us Max Payne! That was brilliant!

So when you had the green keys in your truck it rode just as harsh as your stock keys maxed to the crossmember? Just curious.

I hope my wife doesn't find out about the whopping $40 I was ripped off for buying the green keys 2 yrs ago. If you can improve the appearance of a $35K-$50K truck by a simple swap that costs less than a tank of gas a seriously doubt anyone is getting ripped off. No different than air intakes, the Tornado, Split fire plugs, BFG tires or stuff like that I guess. Its all up to the individual as to what they decide to purchase.

Whewww...glad you were here to clear things up for us Max Payne! That was brilliant!

So when you had the green keys in your truck it rode just as harsh as your stock keys maxed to the crossmember? Just curious.

I hope my wife doesn't find out about the whopping $40 I was ripped off for buying the green keys 2 yrs ago. If you can improve the appearance of a $35K-$50K truck by a simple swap that costs less than a tank of gas a seriously doubt anyone is getting ripped off. No different than air intakes, the Tornado, Split fire plugs, BFG tires or stuff like that I guess. Its all up to the individual as to what they decide to purchase.My truck has never had green keys installed. I have a firm enough grasp of the concept of suspension to know that they are NO DIFFERENT than a cranked stock adjuster (unless you need to go further than the stockers will allow) THE POSITION OF THE HEX IS THE SAME WHEN AT THE DESIRED RIDE-HEIGHT! One bolt is in, one is out, that is all. You cannot tell me there is a differece in ride! Maybe someone let the air out of your tires, but if you have the same torsion bar, in the same position, on the same vehicle, then nothing changed. The only reason I have mine cranked is to compensate for the additional track width of my lift. I have installed them for people who insist, and there is NO DIFFERENCE from cranked stock adjusters. Then I get customers the part # and dealer cost for the green keys so they know how much the tire shop just screwed them. I have seen tire shops charge people $200 for these things. When they bring them to me to install, I explain to them why they aren't neccessary, then I let them watch me level their vehicle without them and giggle to myself at the thought of people throwing them through the window of the tire shop that sold them. I do not like to see false information spread around on a forum that is meant to help and educate people. Go try and justify your purchase elswhere. And while we are at it, did you save 10 MPG with your Air Tornado too?

I bought the keys before my truck was here and after doing it I am positive I could have done the same thing without the new keys. I actually wanted to stay below 2" but 2" was the minimum with the green keys. If I had rebound adjustment on my ranchos It would be better.

max payne,

I agree with your last 2 posts. I was trying to figure out if the green keys changed the postion of the tb in relation to the lower arm and the frame. As you know the postion of the tb really effects the "lever action" that you were talking about. On our 358 dirt mod race car you can change the tb location to greatly effect the "lever action". I hope I didn't cause any confusion.

loki nine,

Thanks for the answer.

I tell you what, calling people liars, saying they are retarded and saying people who do a mod for their own personal use are wasting their $$$ is totally uncalled for and BS pal! Your belief is just that...your belief based on your own experience and that is it...period. There is nothing that makes your experience any more "right" than my experience. I never said I was right and those that disagree are retarded, only said that it was my experience with my truck. Many others have had the same result as I have. You do not drive my truck or know anything about it. Not many trucks are the same and can have different results using the same mods.

Trust me, before I specifically tested them I was thinking the same thing that logic tells me that there can not be a difference and it should ride even rougher with the keys. That was until i tested them one set up after another and back again. NOW just thinking about it maybe both sides are correct because I am not comparing apples to apples because my suspension is at 2" and not 1.5" like stock keys cranked. Maybe the suspension, since it is a different position and the control arms are at different angles it allows a "sweet spot" if you will at this setting on my truck??? Maybe the situations would be the same if 1.5" was compared to 1.5"? Never tried 1.5" on mine so i can't comment on that setting. I do know that when I first installed the keys that I had it cranked to 2.5" to get it perfectly level and the ride was crazy. It was so soft it was bouncey and basically too unstable and unsafe to drive. My first impression was that they were junk and a waste of $$$. I then backed it down to 2" and the ride was just right. Maybe my set up has the suspension at a ride height which is just above the "harsh" ride and below the bounce? Another factor maybe that I have the 6.0L and not the heavier DMax which may make it ride easier, don't know?

To say you are right and everyone else is wrong is NOT what this forum should be about either. It should be about people sharing their experiences and answering peoples questions based on those experiences no matter how they might differ from others. No different than someone saying they love BFG tires and another saying they had a blowout with theirs and all BFG's suck.

"The ONLY things that could increase the load on the bars are: A) more weight in the truck. B) wider front track width. C) Turning the key so far that the suspension hits the stops, then keep turning the adjuster."

Max Payne;
There are loads induced on the springs every time the suspension has vertical movement (like simply hitting bumps while driving, not to mention things like acceleration squat, lateral forces transfering momentum weight while turning, etc, etc...)
Making statements that are obviously not true reduces the value of everything else that follows.
Unless GM has been your only employer (they are relatively recent to the torsion bar scene), you being a Master Tech, it is difficult for me to understand your reluctance regarding indexing when it's been pretty standard practice on vehicles that have had torsion suspensions for many years (like Porsche). Indexing is also pretty common in the racing circuits.

Look, the bottom line is this, there is no such thing as a progressive rate torsion bar. All torsion bars are single rate springs with a finite range of motion, the more you wind them up, the tighter they are. The tighter they are, the harsher the ride is. when cranked excessively they will over-react & over-compensate on any downward thrust. This WILL negatively effect ride quality.

There is more than enough info in this thread to be able to decide for yourselves
Good luck to all.

Well here goes. This is my first post. I’ve been reading this board for quite a while now and have learned a great deal. The information presented by you all is pretty amazing. It was after all your posts and generous information that convinced me to take the plunge… 2005 Chev K3500 SRW D/A LT (kinda’ gives me the chills just typing it). What a truck!<O:p</O:p

Anyway it seems that most of you are correct, you just don’t have the pictures to show what you mean. Since a picture is worth a thousand words, here are some pictures and a few hundred words to go along.
<O:p</O:p
Disclaimer: I’m definitely no expert. Drawings are crude and not to scale. All angles, dimensions, and values are estimates and in most cases exaggerated to help visualize what is happening.
<O:p</O:p
Drawing No. 1: Ok, assume the front end of your truck is lifted, wheels off the ground (at the stops or hanging by the shocks). Keys are out and therefore no load on the torsion bars. In order to install my (exaggerated) stock key, you need to “pre-load” the torsion bar by cranking the key 35 degrees. The “green key” will require 55 degrees of pre-load. That equates to 20 degrees of additional force (torsional moment for you “engineers”) on the torsion bar.
<O:p</O:p
Drawing No. 2: Now what happens when you drop the front end to the ground? The ground applies a force to the bottom of the tire (easy engineers, I know it’s backwards but it helps with the visualization), through the wheel and to the end of the A-arm. This results in even more torque on the torsion bar. Eventually as the front end settles to the ground, the torsion bar is “twisted” enough to be able to support the load. Add more weight to the front end and it will drop a little, take weight off the front end and it will rise a little.
<O:p</O:p
Drawing No. 3: In order to increase the height of the front end we decide to crank up the key with the adjusting bolt or add keys with a different “index” like the “green keys” (does the same thing, just different overall capability as we will see later). This time when we drop the front end the torsion bar reaches equilibrium sooner because of the greater pre-load we put on the torsion bar. Result… instant front end lift.
<O:p</O:p
Drawing No. 4: Kind of self explanatory.
<O:p</O:p
This drawing also helps to explain why the ride might suffer and a few other things. Here’s something interesting: a lifted (using keys) front end actually has less torque on the torsion bars. SAY WHAT! This is where the reduced track comes into play. Now we have a reduced lever or moment arm and the truck still weighs the same. Lost me? You’ve probably torqued down your lug nuts with a nice big, long handled torque or lug wrench… try doing it with a 5 in long ¼ in socket wrench. There’s your moment arm. In this case we have 2000 lbs acting up through the wheel and a 10 in moment arm vs. the same 2000 lbs and a13 in moment arm of the stock setup. Same weight, larger moment arm = more torque. THAT is why you tend to get a harsher or more firm ride with the higher lifts. Shorter moment arm requires a lot more force to move the suspension geometry.
<O:p</O:p
With the lift you also have less downward suspension travel before the bumpers or shock hang and don’t forget the greater preload on that last few inches… firmer ride. Also, there is the potential for exceeding the torsional load capability of the torsion bar because of the greater upward travel capability. Like say when you hit the railroad tracks doing 70 (I love this truck) and come down a little hard on the front end.
<O:p</O:p<O:p</O:p
Drawing No. 5: This just shows what some of you were saying about the difference between using the adjusting bolt or the “green keys”… there isn’t any. The “green keys” just start where the stock keys and maxed out bolt leaves off. Remember that 20 degree difference when we started. By cranking up the adjusting bolt on the stock keys you get the exact same result as the “green keys” with the adjusting bolt backed out. Although as some have mentioned, having the adjusting bolt all the way up might present its own problem.
<O:p</O:p<O:p</O:p
Had to reduce the resolution quite a bit. Hope it still helps.

03GMC2500HD, If I offended you, sorry. I get real hot under the collar when people preach these things on HD's, I don't like to see anyone get ripped off because they are misinformed.

Loki Nine, I am talking about static ride height. Try to follow with me: Each key is turning the bar the exact amount of degrees, and the control arm follows the exact same amount of degrees, therefore nothing has changed, regarding preload. I realize that keys are benificial when you need more than the stock adjuster can provide (such as Z71's) But this isn't the case on HD's. Any more than the 1.5"-2" than the stock adjusters provide and you will not be able to align to specs. There isn't enough room in the slots to provide more than 2* positive caster (while keeping camber reasonable), stock spec is around 4.5*+. You can get away with it, but handling begins to suffer due to topping out and wandering. If more lift is needed, consider a real lift kit.

Also, I have replaced 2 front half-shafts that exploded on vehicles running the bars cranked with spacers in the shock mounts. They let the suspension droop to far, causing the inner joints to bind and explode. Be carefull not to space them too far (about 1" in these cases)

People feel that they are preloading the bar more because they have to crank the crap out of the green keys to get them in. This is only because the suspension has hit the stops. If the stops were moved to allow the arms to hang down the same amount of degrees that the green keys are indexed, then they would install the same as stock.

Keep in mind, I do this stuff for a living. I have real-world experience with this stuff every day. I don't just sit in an office and think about it, I DO IT.

03GMC2500HD, If I offended you, sorry. I get real hot under the collar when people preach these things on HD's, I don't like to see anyone get ripped off because they are misinformed.
Not offended here just that people should be open minded some and respect other peoples views/experience and not be so narrow minded. If people are stating facts (not preaching) from their own experiences then they are not misinforming anyone. Same thing with a Westers, some people say they get 30hp increases and say they are the greatest thing since sliced bread then you have some that say they only got about 5hp increase or non at all and say they are a big waste of $$$. Is one more right than the other or is one misinforming other members? No, because it is just their own experiences/opinions on that product.

I do agree with you on shops ripping people off though as i have seen people charged $200 for the same thing also or $75 to crank the stock bars when all they have to do is lay under the truck and spend 5 min doing it themselves. That I do agree that is RAPE! $40-$50 out of pocket for somebody to try something on their own is not getting ripped off though.

I do agree with everything that has been stated so far as far as what is happening mechanically with the front suspension. Trust me I think and have always thought the same way, only my opinion differs because of my own results and how my truck reacted. Any Engineer should know that just because it looks good on paper that it doesn't mean that is how it works in the everyday real world all the time. Prime example. Same thing with a Westers, some people say they get 30hp increases and say they are the greatest thing

As far as broken parts such as half shafts, I can't see how everyday highway driving would cause that. I can definatley see it if you were seriously off roading or WAY over cranked some how. I see you have a lot of performance mods on your truck and i would bet that if those guys had the same type mods that the hard 4WD launches may have played a role in breaking parts. Come on if you spend the $$$ on performance mods you gotta run it hard some, right, or whats the point?

Agreed.
(The people I spoke of that broke parts were both said to be crossing over water bars at an angle when it happened, both were hunting)