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Discussion Starter #1
Took ya'lls advice and cranked each bolt 5 turns, have this much adjustment left over, raised it about 1.4 inches as measured at the tow bars, looks alot better. Are these green keys, or are they ONLY available for purchase and not factory?


Edited by: Diesel Power
 

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Looks good. Thanks for the pics. How long did it take?
 

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Wickedsprint said:
Are these green keys, or are they ONLY available for purchase and not factory?
Take a look at your 2nd pic, the one that shows the purple paint splash on the key. Still think it's a green key?


BTW; the greenies come standard on the 1/2 tons, but can be purchased from the parts counter or from GM Parts.
 

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Discussion Starter #7
I also saw the green part of the paint too, so actually had NO idea which keys they were...*shrugs*, but happy since the truck sits pretty level with a bunch of threads left on the bolts.
 

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Now that you've raised the front end you need to watch the tire wear. Unfortunately raising/lowering the front end causes a change in the camber angle. Anytime the camber angle changes the toe angle also changes. I raised the front of my '03 CC SB to make the truck more level. I max'd out my adjusters and raised the truck almost 2". Now, when measuring the ride height using the flat part of the frame under the cab, I have a 1/2" difference in height between the front and rear along the length of the frame. Front being lower of course.


Also, another thing to consider when you're adjusting the torsion bars, park the truck on a level surface. As you adjust the bars to increase the height, keep the truck level side to side. I do this by checking the level on the front and rear of the truck bed. I also check the level under the truck by putting the level across the frame. All three surfaces may not be exactly level so you make have to find a happy median.


When I'm doing an alignment and I have to resort to the torsion bars to correct an alignment I always check the level side to side. It really looks bad when a vehicle is going down the road and leans to one side or the other.
 

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I put a set of GM green keys on 2 weeks ago.


They both had a light green paint splash on them. Don't know if my keys are different than yours, but after install I gained 1.5" without turning the torsion screws all (except enough to thread the end of the torsion screw itself). I cranked a couple of turns more to raise the front another .5" to 2" overall. My front is now 1/2" lower than the rear. I probably have about 4-5 more threads available than in your picture, but each truck differs slightly.


My ride is much smoother after cranking the green keys 2" than it was when I cranked the stock keys all the way in to get 2". Notsdale is correct - get an alignment soon.


Doug
 

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DMax_Doug said:
My ride is much smoother after cranking the green keys 2" than it was when I cranked the stock keys all the way in to get 2".

OK, maybe I am missing something here. Maybe someone can explain this to me. It was my understanding (and I may be mistaken here) that the green keys simply change the starting position of the torsion bar. However, for a given front end height, the torsion bars have to have a certain amount of twist or "pre-load" to maintain that height. They only thing the green keys do is give you the ability to reach that point sooner...ie, when you reach that point you will have more adjustment left on the adjuster screws.


So...I don't understand how going to the green keys, and adjusting the ride level to the same height as was reached with the stock keys, can result in a smoother ride. What am I missing here?


Thanks,


John
 

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You are correct. We can argue this till our lips turn blue (green).

All the green keys do is change the starting orientation of the bars.

All torsion bars are is a long bar with hexagon ends. The keys have hexagon holes in them and the lower control arm has a hexagon hole. The bar fits into each component. When you rotate the key, you rotate the bar, which rotates the lower control arm downwards raising the truck. The bars "twist" and "untwist" only during suspension travel. That is the spring.

The problem you create when you lift the front with the torsion bars is you shift the travel envelope out of center. In otherwords, when driving down the road and you drive over a sharp dip in the road, your suspension is already almost at it's lowest travel so it can't drop the tire much further.... you lose road contact..... That is a no-no in normal driving.

From the article link below....

"The range of available travel is determined by the distance between the bump-stops. The gap between the upper set of bump-stops determines the available downward travel. The gap between the lower bump-stops relates to the upward travel on the wheel. If you check the distance between the upper bump-stops at factory spec, you'll notice that the distance here is often not much greater than two finger spaces. If you adjust your torsion bars, which forces the upper control arms down to raise the vehicle. The gap between the upper bump-stops becomes even more tightly-closed together. This action greatly affects the amount the front wheels can 'droop' from the normal rest height."

Personally... I wouldn't do it unless you have a truck that came from the factory with the one or both of the adjuster bolts already just about used up.

Raising the front with the adjusters weakens the steering gear. Ask Michael Tomac.

It also drops the upper control arm into the bump stop, restricting downward travel. This tends to create a harsh ride although not as harsh as the old C/K trucks would get.

I have mine jacked with the stock parts. Ride ain't bad but if I wanted to go higher, I'd be going body or suspension lift.

Read ThisEdited by: hoot
 

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I can't explain it either, but Hoot's post notwithstanding, my truck rides smoother and better with the green keys half cranked then the stock ones almost maxed. I don't bottom or top out my shocks or suspension, nor do I have any steering problems. And it sits higher too (41.5" front, 42.5" rear).

Perhaps something ugly (or expensive) will happen down the road because of this "mod", but perhaps not. Only time will tell...
 

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How many miles do you have on the green keys Jim?


I also find that the ride is nicer with the green keys in my truck, compared to my dad's truck with the stock torsion bar bolts maxed. In fact, the bolts on mine are backed out further than stock and it still sits higher than my dad's does with his cranked all the way in.
 

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Hoot,


Excellent info - thanks. I think moderation is the key. I've got a new set of tires/rims coming (BFG 285's) that are wider than my current 255/85 tires, so I'm looking for some wiggle room. After the install, I'll probably back mine down half an inch if there's no rubbing, since the ride quality is measurably stiffer at 2" increase vs. 1.5".


Doug
 

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There is no magic geometrical change the green keys make.

They simply reposition the starting point of adjustment.

The suspension has an uppper limit and a lower limit of travel. By rotating the bars by whatever keys you have installed, you are doing the same exact thing....

You are selecting the postion you want the suspension to be in with reference to the upper and lower limits. The green keys simply put the starting point in a position that gives you more adjusting bolt threads, thus giving you more adjustment to the high side and less to the low side.

To those experiencing better ride quality at higher front height... it can be explained a number of ways...

Did you make other changes at the same time?
Shocks, Tires, Air pressure?

There also could be some dynamics with the tire, shock combination that works better with the front higher. Hard to say.

I know for sure if you jacked up the C/K's up they had a terrible ride. GM did a nice job redesigning this HD suspension to be more tolerant of height changes.

My comment on weakness attributed to the higher setting should only concern those who race or pull in competition. Michael Tomac discovered that lowering the bars to stock height all but eliminated bending tierods.Edited by: hoot
 

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From the factory the lower control arms and the tie rods are fairly level all way across from side to side. When only the front end is raised with no other alterations to the suspension, the tie rods and control arms drop down and are no longer level all the way across. It is the dropping of these parts that creates additional stress. This additional stress is on the tie rods, pittman arm and idler arm.


To put this in perspective, if you have the opportunity to lift the front end from under both lower control arms at the same time, if the tie rods are level with the centerlink, both tires will respond equally when one tire is moved in/out. If the tie rods are lower than the centerlink you will notice that when the tire is moved in/out the tie rods will push up on the center link. Over time then creates additional wear and sloppyness in the steering.
 

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hoot said:
To those experiencing better ride quality at higher front height... it can be explained a number of ways...

Did you make other changes at the same time?
Shocks, Tires, Air pressure?
Nope -- same shocks, tires and pressure, before and after.

I wish there was some way to explain it, because my logical mind wants to know, but I've never found a way. But my seat-of-the-pants meter sure knows there's a difference.
 

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Notsdale said:
From the factory the lower control arms and the tie rods are fairly level all way across from side to side.
It was interesting, when I measured the distances up to the frame on the right & left front, how much lower the driver's side was than the passenger side. It was over 1/2" different. You'd think that the factory could do a better job of leveling...
 
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