New torsion keys, do I also need the bars?

[88lance]

'02 Z71 Tahoe, just picked it up the other day.
The front looks stock, it's got the factory rake look.
Decided I would level it, so I crawled under to find the keys completely maxed out.

Since it's still sitting down in the front, can I just get 3" keys and turn it up more, or since it's maxed out, does that mean the bars are worn out and need replaced also?

 

[Alex_M]

The bars may have sagged some, but not necessarily "worn out". Yes, I would just get some lift keys and set it at the height you desire. Remember, you will need to get a front end alignment after adjusting the front ride height. Do some research - not all front end alignments are created equal. I have two specific dealers I am willing to take my vehicles to for front end alignments and pretty much nobody else. Just because they are a dealer does not mean they are good either, I have one dealer I will not use for anything largely because of an experience I had using them for a front end alignment.

 

[88lance]

The bars may have sagged some, but not necessarily "worn out". Yes, I would just get some lift keys and set it at the height you desire. Remember, you will need to get a front end alignment after adjusting the front ride height. Do some research - not all front end alignments are created equal. I have two specific dealers I am willing to take my vehicles to for front end alignments and pretty much nobody else. Just because they are a dealer does not mean they are good either, I have one dealer I will not use for anything largely because of an experience I had using them for a front end alignment.

Luckily I have a guy that has done very well at alignments also, So I was already planning to bring it to him.
If I get a 3" key, will it be lifting 3" from what should have been stock, or would it just lift 3" from where it sits now? I would think since the bars are already sagged some, it would just be lifting it however much the key says from its current height?
I think I only really need 2". When a key advertises 2", is it advertising 2" as the max it can go, or 2 in where it's sitting when you first put it on before cranking on it?

 

[Alex_M]

A 3" key will raise it 3" above where it is now. In my experience the advertised lift of a key is at their maximum height.

 

[BoatyMcBoatface]

I just replaced mine with new re-indexed keys to level the front. I only brought it within a 1/2 inch level of the rear. About 2 in total. I replaced the sway bar links with stock length and i did add the extended shock mounts but i don't think it was necessary as i ran without the shock extenders for the summer and no issues. I did have it realigned since it changes the camber and toe quite a bit. The caster was off too but not bad. If you push it to the limit like 3" you may need to swap out the upper control arms as you may not get the camber into spec. Moog and a few others make upper control arms with a indexable ball joint to get that extra camber. This was done on a K2500 yukon xl

 

[88lance]

Great, I think I only need 2" it looks like, so maybe I should just order 3's and not turn them up much? If I order 2's, I would have to max them out to get the 2", so I'm guessing buying a 3 and just not turning it up much would give the 2" I need pretty easily.
Luckily 2" will probably let me keep my other suspension parts stock it seems

 

[88lance]

Wanted to revive this thread after my interesting find on the torsion bar issue. And post my "fix", in case someone else runs into this. (Note this is all before alignment)

So the truck sits as:
Rear: 37.75"
Front: 35.50"

I put the 3" keys, and maxed them out at first.
To my disappointment the front only came up 1". ...on a 3" key maxed out..
I took the key back out and started checking out the torsion bar, and noticed the front of the bar that goes into the lower control arm is really wallowed out.
I'm not sure if it is the shoulders on the bar itself, or the holes in the arms, or both. But you can turn the bar almost 1/8 turn before it hits the other shoulder .
With how little of a turn makes a big difference, I got to thinking that this could actually be affecting a lot of the lift.

So I decided before buying new bars or control arms, I would make shims.

Hose clamp material is pretty strong, so I used it to fish through the gap on each shoulder of the torsion bar through the control arm. It took 2 strips stacked to fill the gap at each shoulder. This keeps the torsion bar from turning 1/8 turn before actually beginning to lift the truck. It will begin lifting almost immediately.

Sure enough, the truck lifted slightly past level. Actually had to back it off a little bit to get it a quarter inch below the rear.

Rear: 37.75
Front: 37.50

Will this continue to work? I'm not sure, but I figured it was worth a try, and also wanted to write it here in case someone else runs into the same issue. I'll update if it falls apart next week or something. the good news is, if it fails and a shim comes out, it will just start sagging slightly in the front again, so there is not really any risk of it coming apart on the road or being a danger.

Someday I'll probably just need to replace the bars and control arms altogether

 

[Alex_M]

The arm is not wallowed out. All of these trucks are like that - there is a wide tolerance between the end of the torsion bar and the control arm interface by design.

What you did I don't see causing any issues, but what you found is no cause for alarm either. Peculiar that the new keys only raised the front 1" - I would be interested to see a new key compared to an old key to see if the angle of the "socket" on the key is noticably different than your stock key, or at least as much different as it's supposed to be.

Also - when measuring lift, for the most accurate measurement go from the center of the hub to your wheel arch. This takes the size/pressure/level of wear of the tires completely out of the equation.

 

[BlaineBug]

Is it possible that the bars are swapped from left to right? I read something else awhile back with that issue. They should be labeled or stamped I believe, so you can check.

 

[88lance]

I'm not sure why I wasn't getting notifications on this thread, sorry for the late response. I didn't know anyone responded. Haha
Interesting to know it is normal for them to be that loose. I did compare the keys and they are definitely turned more than the stock. It seems that the torsion bars themselves must just be worn down then. One a lot more than the other apparently, since It is sitting level with one key almost maxed out and the other one only about a quarter of the way turned in. Part of that could also have to do with the shim though.
I did check the stamp on the bars, and they are on the correct sides. I guess that's just how it is going to be, unless I decide to throw new bars on it someday.
Oddly enough the side that's only turned a quarter is still sitting slightly higher, I noticed that today. I thought about turning it down even more, but then noticed that the tire is also pulled in on the bottom on that side. Makes me wonder if the alignment guy screwed up, and if it will actually drop a little bit back towards level if he corrects that tire. 1/4" higher on that side. Was level when I brought it to him.
I may run it back by the alignment shop before I mess with the torsion bar anymore, adjusting that may fix it itself.