Torsion Bar Adjustments

[MarkD51]

Hi all,
About a month ago, was doing some detailing on the fender wells, cleaning up suspension components, grease job, etc on my 1997 4WD 4DR Tahoe.

Well, to get to the point, just out of curiosity, decided to take tape measure to see how front ride height looked. I had found that my passenger side was more than 3/4" lower than the driver's side. (Measured at the Fender Lip)

Upon inspection, I noted that the Torsion Bar Key Bolt on the passenger side looked to be much further screwed out than the driver's side by a good 5-6 threads.

Since I am the original owner, and can recall way back looking at these when the truck was new, I seem to remember both adjustment bolts showing an equal amount of threads.

So, out came floor jack, some penetrating spray, the appropriate Socket, and 1/2" breaker bar, and began to adjust the passenger side only.

I did not touch the driver's side adjustment bolt at all. My reasoning, was with some common sense, that I've never seen any bolt in my lifetime somehow "tighten itself", only ever loosen.

I started with a full turn, then two, and began to see the height was coming up, but still no cigar. Each time, I lowered the jack, bounced on the front end a bit so the suspension would settle. I was getting closer to matching.

As I began to get closer, to within a 1/4" difference, the passenger side still a tiny bit lower, I took the truck for about a 1-1/2 mile ride, letting the suspension jostle around a bit, then back on the concrete slab to check again, and again. I probably took the truck for another 4-5 little rides as I got closer and closer to matching height.

I did take note of exact measurements, I was writing them down each time I made an adjustment, and one funny thing I noted, that although I did not adjust-touch the driver's side Bolt, the driver's side seemed to ever so slightly increase in height as well by perhaps 3/16". Is this possible?

Before I began these adjustments, I had sort of noted that the truck's ride seemed like crap. Lots of bouncing, a funny ride, steering seemed shoddy in comparison to the after adjustments.

After about an hour's time, just taking my time, with no rush, I seemed to have gotten a virtual perfect match in height on both sides. If there's still a difference, that difference might be as little as 1/16" variance.

Betting that by the time I got done, I figure I did close to 5-1/2 to 6 full tightening turns of the Passenger Torsion Bar Key Adjustment Screw. Both now appear to match quite closely as to how many threads now show.

Again, after I completed this adjustment, the truck seemed to ride, and handle much better. Instead of what commonly happens, that the ride is said to become harsher, my ride handling, and steering got much better.

Wheel alignment, although none was done after, seems great, the truck tracks like it's on rails, no pull, no funny steer, truck feels great, rides great, looks better, no odd looking camber of the wheels-tires.

As I close, and wish to garner comments, does it sound like I did all OK?


Since these are old tires, I'm not going to worry about them at this point, but when the time perhaps comes that I wish to throw a nice new set of 20's with perhaps 275/55-20 tires, I will of course seriously consider an alignment to get the longest life from the tires.

I'll include a few recent pics so you folks can see how the truck's stance looks.

Keep in mind as well, that I do have Firestone Ride Rite Air Bags on the back, and that I keep them inflated at 40psi at all times, even when not carrying any loads.
Thanks folks, Mark

 

[MarkD51]

Another pic, not sure if I included this one in my first post.
Tires-Wheels currently on the truck are 16"x8.5" with 275/70-16 Michelin LTX.
Mark

 

[Slammed]

Sounds ok to me maybe i should adjust mine too

 

[Zipper369]

I'm thinking the same thing as well. My driveway has a sideways slope to it, so my Tahoe always sits a little off to the passenger side. I'll have to park elsewhere and check how mine sits.

 

[MarkD51]

I'm thinking the same thing as well. My driveway has a sideways slope to it, so my Tahoe always sits a little off to the passenger side. I'll have to park elsewhere and check how mine sits.

That's exactly what I thought too, that my car port slab was probably not the best place to check as far as being perfectly level and smooth, but the height measurements on my Tahoe were so far off, I knew something had to be done.

At some future point I'll probably check mine again somewhere else, and see what measurements I get?

A floor Jack, can of penetrant spray, socket, breaker bar, and tape measure are about it.

There is no doubt probably no correct precise setting, where somebody can come along and say "oh, your truck supposed to sit so high". That measurement will of course vary dependent upon tire size for one.
Mark

 

[Zipper369]

There is no doubt probably no correct precise setting, where somebody can come along and say "oh, your truck supposed to sit so high".

Good point, but I suppose it's mostly what height feels like it has the best handling. I have no idea if the front and rear should be equal or have a little bit of forward/rear lean. I'll check that as well tomorrow when I measure my Tahoe's stance. I guess I'll go from there. Hopefully it's close to even all around.

 

[MarkD51]

Good point, but I suppose it's mostly what height feels like it has the best handling. I have no idea if the front and rear should be equal or have a little bit of forward/rear lean. I'll check that as well tomorrow when I measure my Tahoe's stance. I guess I'll go from there. Hopefully it's close to even all around.

I think I read once somewhere, that it was sort of common for the driver's side to lose height over time, due to the Gas Tank being on that side. Maybe such had a more detrimental sagging effect on the rear springs, rather than the front Torsion Bar?

Of course in my personal instance, that wasn't evidently the case.

What it appears to me what happened on my Tahoe, was over time passing, the Passenger Side Bar Key Adjustment Bolt slowly backed its way out a number of threads-turns.

Perhaps at some future point, where I can check height again, and perhaps further fine tune, maybe I should place a drop of medium strength threadlocker on each bolt?

That this will keep those bolts somewhat "locked in", but won't be to the point where torch would be needed to further adjust in the future.
Mark

 

[Zipper369]

That's probably a good idea. I don't see what it would hurt. Fortunately, I don't think mine backed out (at least not to a noticeable extent as yours did). A few months back I was down there replacing one of the mounts that hold the torsion bar cross-member to the main frame and both sides looked about the same.

 

[lesterl]

How about a Jam Nut?

 

[MarkD51]

How about a Jam Nut?

Hi Lester,
For sure a Jam Nut would probably be the best positive means of locking said bolts that they cannot possibly walk out.

This for sure would then mean removing both bolts, and starting over fresh, installing Jam Nuts and re-install, which in my own personal instance sounds like a can of worms. Think I'd rather not go there unless absolutely necessary.

It probably took the 15 years for this to happen. In other's cases, and other's vehicles, where there's considerable rust present, this probably isn't a problem, as those Bolts may very well be "rusted" into place.

In my case, since my Tahoe has quite minimal underside corrosion due to the last 10 years in the desert southwest, this simple slight loosening might not be unusual?

Perhaps even a simple de-greasing on the bolts with a solvent, or something like Carb Cleaner, and just a small dab-dot of 100% Silicone RTV Sealant on each Bolt where it meets the Key in combination with a drop of Threadlocker on each might also keep things in place?

Perhaps I'm getting too anal, and that it might take another 15 years for any adjustment changes occurring? LOL
Mark

 

[lesterl]

I hear ya, sounds reasonable....