Hello. I have read and heard a lot about the green keys that can be used on your torsion bars to get up to 2" lift on the front end and it sounds like a pretty good way to go. What is the difference between these and just cranking your OEM torsion bars? Just more height? Also, what is the difference between a couple of turns and cranking them all the way in without the green keys? Will it hurt any more to go further? GM has to have these set at the lower levels for some reason....anyone know why?


Thanks, Jason

Yes the green keys allow you to take it up another 1/2" over the about 1.5" with the stock keys.

Will it hurt? Probably not a lot. If anything some parts might wear a little sooner.

The higher you raise the truck with the torsion bars, the farther you take your suspension out of "center travel" between the stops.

Also your track width will decrease. If you ever watched these trucks going down the road you'll notice as the tires drop down, they also pull in.Edited by: hoot

Does anyone know if the green keys will work in conjunction with a lift kit?

From my experience;


just cranking the stock keys made the truck feel very springy on the front end. When I installed the green keys, the ride quality returned. Then when I added the bilstein 5100s to control the heavy H2s, my ride got better than stock. Im extremely happy with the ride quality and look right now. I dont know exactly how it all works, but this is my experience.


On the downside, the angle on the front driveshafts is more than I would like, but I heard that our trucks have the same front shafts and CV joints as the H2 and are supposed to be good strong parts...


Time will tell http://www.dieselplace.com/forum/smileys/Big Smile.gif

If you do a suspension lift, don't bother with the keys.

Hoot I thought this would be a "here we go again" thread but you explained it very well.http://www.dieselplace.com/forum/smileys/Big Smile.gif Only thing I would comment on is the track width part. What you say is true but this is why it is important to get an alignment after raising over say an inch. An alignment will correct this or at least it did on my truck.


2Much I had just about the same experience as you with the cranking vs. the green keys comparision. Cranking was harsh, green keys smoother, not stock, but much smoother! Still running the stock shocks though but I would like to try the Bilstein 5100's but haven't made the switch. And yes the HD's have beefier part!


Hoot is right Diesel, if you go with a lift why bother! There are alot of who are running the keys with the lift without problem but I would just say it had to depend on the lift and how the truck sets.

Thanks a lot guys for the speedy replies! I didnt mean for it to be a "here we go again" thread. I just wondered what the added benefits/costs of the keys were. I've been thinking of getting them for a while, now putting the order in today.


Thanks again for all your help. This board it a tremendous asset to anyone. Jason

I don't think alignment can change track width. Adjustments can only be made at the upper control arm. This will fix camber but track width will be narrower.

Hoot I misunderstood what you said before. I just caught the part where it said they were pulled in. Your probably right but what are we talking about a 1/4" or so?

Hoot I misunderstood what you said before. I just caught the part where it said they were pulled in. Your probably right but what are we talking about a 1/4" or so?

Don't know exactly how much we're talking but watching a truck along side going over bumps, the tires move in and out of the wheel wells a good bit.

Yet another negative to extreme torsion lift. Truck sits higher with a narrower track.Edited by: hoot

ok - here's a question - what about LOWERING the truck 1 or 2" by cranking down on the torsion bars? is that a good/bad idea? Will that tweek the alignment off? I bought lowering shackles for the rear and wanted to lower the front just a little bit... (the wife wants to get in without using a ladder...)


Let me know what you think... thanks! http://www.dieselplace.com/forum/smileys/Embarrased.gif

The higher you go, the more "bump steer" you will encounter as the suspension cycles, That and scrub.





Bump steer is change in toe.


Scrub is like Hoot was stating about track width.





Dunno how adjusting the stock keys affected the ride to a spongy feel, yet other keys firmed it up??? The key has bearing only on how high you can ultimately go...

I'm a little confused on the green key vs stock key cranked ride quality. The torsion bars have some given torsional rate. There is some given preload on the torsion bars that needs to occur to support the truck at some given height. If we set the truck at the same height with stock or green keys...the preload is the same. So how can the ride be different? Edited by: Trippin

Exactly what I've been wondering. Trippin just worded it better. The stock keys get us up about as far as I would reccommend. Any further and there will be diminished "drop out" capabilities in the front suspension as it is nearly topped out...

Do a search on green keys. There are several threads explaining the differences between them from those that have swapped them and have compared them to just cranking the stock bars.

Fabtech makes spindles that raise the trucks front end 3 inches for about $400 and maintain the stock ride. Sounds like a hot tip for a moderate lift.

MOTO HEAD


Can you give me some more details on the Fabtech 3" lift. I went to their web site but it only talks about the 6" & 8". I had a 6.0 2001 identical to my 2002 Dmax, when I cranked the torsion bars on the 6.0 I did not feel a big diff in ride but just one turn on the Dmax and the ride goes bad. Cant explain why.

From one moto head to another, they're listed in 4 wheel parts print catalog (www.4wheelparts.com (http://www.4wheelparts.com)) part #FTS2599-7HD for $426.99. They say they're good up to 305/70-16's.


Isn't Axton Virginia where David Bailey's from.

Does anyone know if the green keys will work in conjunction with a lift kit?


Most life kits already have the keys in them as part of the hardware.

From my experience;


just cranking the stock keys made the truck feel very springy on the front end. When I installed the green keys, the ride quality returned. Then when I added the bilstein 5100s to control the heavy H2s, my ride got better than stock. Im extremely happy with the ride quality and look right now. I dont know exactly how it all works, but this is my experience.








I went through the same process, and I concur, the keys with the 'steins are the way to go.

I believe the Fabtech spindle lift is for 2wd only.

Jeli is right the spindles are for 2wd trucks.

The angle of the control arm affects the initial suspension stiffness. If the control arm is 90 deg to the ground, it will have the most torque applied to the torsion bar, hence a softer initial spring rate.


Going to extremes, if the control arm is perpendicular to the ground, the spring rate is infinite, no movement. And if the arm is 45 deg, it takes more force to move the suspension 1" than 90 deg. Divide the 90 deg spring rate by the cosine of 45 deg (I think).


So while the torsion bar spring rate does not change, the geometries affect on the effective spring rate does. The best suspensions have the control arm at 90 deg static, so that when the wheel travels, the effective spring rate goes up due to the geometry change.

When you lift the truck via the torsion bars (or green keys) more than 1.5 inchs extra, measured at the mid point on the wheel well openings, the only thing you realy wear out faster is the rubber C.V. joint boots, because every revolution that it makes, it comes back in contact with itself (the pleats) because of the more extreme angle it is now on. When you lift it this much you also cause the drag link on the steering to be at a disadvantage. The drag link has a rearward bend in it just before it connects with the inside tie rod ball joint. The tie rods come in at a steeper angle and when you push on the fuel in 4 WD it pushes up and back on the drag link to create a toe in situation. The drag link is mounted to the pitman arm and idler arm with ball joints as well, which in turn lets it twist up and down slightly (in a perpendicular motion to the ground) at the bend on the ends where the tie rods connect. So ergo, when under power in 4WD the pulling effect from the front tires cause the wheels to pull toward the front center of the truck. This in turn pushes in on the tie rods which are at an angle to push back up on the drag link. It swings up, instant toe in situation. Just reverse the process for breaking, instant toe out. But you don't have to be in 4WD for that one. So in turn you get more rapid tire wear from this situation. If we could maintain the side to side steering movement of the drag link, but stop the up and down movement at the ends of the drag link, than we could just install tie rod sleeves to stiffen up those tiny little tooth pick sized tie rods, and we could crank them up with no problems. As far as changing the ride plushness with cranking the torsion bars or installing the green keys, they dont change the metallurgy or static energy in the bars. You would have to change the torsion bars themselves for a different spring rate altogether. A spring doesn't change it's rate if you just lean it over compared to standing it up, right? Changing the tires from an E rating to a D rating will soften the ride a little. I truly hope this clears some stuff up. Feel free to test my reaserch to see. Sorry the post was so dang long. It's hard to clearly explain this all in a short breif message. Thanks for being patient and taking the time to read it. Super Diesel

Not sure what all you just said but the extreme toe in situation may explain the Chevy Duramax commercial on TV. The one where the guy gets the call that he needs to pull a bazillion pounds of stuff to the top of the hill in his CC dually 4x4 before the storm moves in. Look at the front wheels on that truck as he is driving it and when he slams on the brakes to stop. Not sure how he drives it with the wheels toed in that far! looks like something is broke in the steering its so bad.

... As far as changing the ride plushness with cranking the torsion bars or installing the green keys, they dont change the metallurgy or static energy in the bars. You would have to change the torsion bars themselves for a different spring rate altogether. A spring doesn't change it's rate if you just lean it over compared to standing it up, right? ...


The angle that you push on something changes how much force is required to move it. Push straight on, you get full force. Push at an angle, and you don't. The spring itself doesn't change.

Has anyone seen a "LEVELING KIT" for our trucks? I have seen them for all other makes but not for the Chevy/GMC's. Do they even make one.http://www.dieselplace.com/forum/smileys/Confused.gif

That is exactly what we are talking about, a "leveling kit" or green keys. You can find leveling kits on Ebay for $75-$100 but all they consist of are two $25 GM green keys.

The ark of the rotation is still the same as before. Super Diesel

Now I'm feeling ignored. http://www.dieselplace.com/forum/smileys/Cry.gif


I guess nobody likes the idea of a *slightly* lowered truck, huh?

From one moto head to another, they're listed in 4 wheel parts print catalog (www.4wheelparts.com (http://www.4wheelparts.com)) part #FTS2599-7HD for $426.99. They say they're good up to 305/70-16's.


Isn't Axton Virginia where David Bailey's from.





I believe it is. Speaking of Bailey, where is he? Supercross on ESPN2 just isn't the same without him...

Newguy, You can lower your truck some by backing out the ajuster bolt for the torsion keys. You will most likely have a slight toe out. So you can either brake out the tape measure and check your alignment or take it in to have it checked and maybe if needed, ajusted. Make sure you back the bolts out, the same amount of turns for each one. Then drive down the street to let the ride hight nutralize, and recheck to make sure your level. I think you may need a big group hug. Super Diesel

Bailey is training/coaching David Vuilliman this season.

awwwwwwww, now I feel all special!


is there a pracital limit to how much it can be lowered? Is 2" ok?


I understand about the alignment thing - and that's no problem to take care of... Thanks for the input Super Diesel! http://www.dieselplace.com/forum/smileys/Approve.gif

I would imagine that you can lower them all the way to the stops. I haven't herd any thing on this before. I would leave the bolts in though, or remove them and put in some shorter ones that stays in some contact with the keys, and keep them in there. Watch your wheel clearances too. Six sides of beef on the hood realy lowers it and gives a cadilac ride too. You might have a vision problem then though. SuperDiesel

Hey Newguy,


Now that you're feelin all warm and fuzzy. Let me know how your lowerin goes. What angle pinion shims are you planing to use with your extended shackles?

I dunno how far you can lower the front by adjusting the torsion bars. When mine was stock - the lower control arms were in contact with the yellow bumpers and probably limited downward wheel travel. Guess you could remove them and try the fit to see how it looks, but I wouldn't advise driving without something in there to avoid metal to metal contact. Some one else here has lowered their truck AND installed H2's with 315's! Look around.


http://www.dieselplace.com/forum/uploads/travel_stop.jpgw

Newguy,


Found an old post that might be of interest.


http://dieselplace.com/forum/forum_posts.asp?TID=1601&KW=bumpstop


Dave

hmmmm, well more intereseting stuff here now... I did look at mine and even new (only 68 miles on the truck right now) it sits on the "bupstops"... so I plan to lower about 1-2". For the back I bought shackles that will lower 1.5" from what I hear.


That's about it, but it won't get any attention for at least a week now, as I'm heading for 'Vegas for the NSCA trade show... For work I install sound/video/lighting equipment and the trade show is comin up, so I'll miss ya'll but will be back and posting how everything went once it's done.


Thanks! http://www.dieselplace.com/forum/smileys/Embarrased.gif

I have about 4 turns on my torsion bars. I remember after making the change the ride was rougher than previous. After doing some investigating under the truck I found that the yellow stops where no longer in contact with the (LCA) lower control arm.


The yellow stop it has a threaded stud protruding from it about an inch or slightly more in length. I put a 1/4" thick washer over the threaded stud reinstalled the stop and now have the yellow stop in contact with the LCA again. 1/4" appears about as much you can space the OEM yellow mount without loosing the yellow stops integrated orientation dowel the protrudes from the stops mounting surface and goes through a small hole in the frame. This dowel and frame hole appear to serve as proper orientation of the stop and prevent the stop from turning side to side. Again any more than 1/4" spacer between the stops mounting surface the truck frame and the dowel doesn't have enough length to mate with the hole in the frame.


This brings me to ask. Is there a OEM stop mount that GM offers that's longer in length than our current stop? Maybe something used on another truck, van application?


Or another idea is to use the aftermarket Timbren replacement stops. Reference Timbren's install page (http://www.timbren.com/install/GMFK25S.pdf)


Using the Timbren's the thought is they're probably the same or very close to the unloaded length of the OEM stops. With the Timbren they use a bolt coming down from the top that's secured into the assembly itself instead of the stud protruding from the assembly like the OEM. This gives you the flexibility to substitute for a longer bolt (reference pdf item #1). Using a longer bolt here would give you the extra length in bite should you want to substitute washer (reference pdf item #3) with one say 1/4" to 1/2" longer in length.


Thoughts good or bad about doing this?


End goal is to obtain increased height in the front while maintaining the stock relationship between spring rates of the stops and the torsion bars. This may take some playing around with to get the right relationship of how much stop engagement of the LCA to have versus torsion bar preload.


These are just random thoughts I'd thought I'd toss out to see what the general consensus of the group here is.


ThanksEdited by: Derek M

ttt