03 Chevy Suburban Torsion Bars

bry21317 · August 7, 2014

Hey,

I have searched and read a lot about the Torsion Bars on these trucks and am not finding 100% if this is my issue or not. So the truck used to ride great, no problems, now for the last 2 years or so at highway speeds it has gotten a lot worse. When you hit a bounce on the Passenger front side, it will get an oscillation from the front passenger side to the Rear Driver side. The two keep springing back and forth until it finally settles down, but at 70+mph that is no fun. I replaced the Front Bump stops the other day, as one was smashed into the Lower Control arm, and the other was damaged. This seems to have helped, but the driver side bump stop is pressed into the LCA. The passenger side one is about 1/4 inch above it. I can adjust the passenger side Torsion bar down, but the Driver side is pretty much maxed out, and my measurements on each of the 4 tires are quite a ways off. There is about 3/4 inch difference between the two Front, higher on the Passenger side of course.

Just looking for some ideas, I will be working on it this weekend and plan to do the Z Trim to get the correct numbers for the Ride Height. Just wondering if it seems that my torsion bars may be worn out, or at least one of them.

Bryan

00Silverado4x4 · August 7, 2014

Not sure what you mean by osicillation from front to rear, do you mean bounce or wandering from side to side? From the reast of your description I'd say that both of your torsion bars are pretty weak.

bry21317 · August 7, 2014

Yes, it is wandering down the highway and also it seems to bounce, oscillate, between the front Passenger and rear driver side back and forth. Sorry about the wrong terminology.

gmtech4 · August 8, 2014

its your shocks dude !!!

replace 4 shocks

txab · August 8, 2014

its your shocks dude !!!

replace 4 shocks

+1

Check them now

bry21317 · August 8, 2014

The shocks have been replaced twice, all 4 while that never fixed the problem. I have new Rear Coil Springs on order, should be here today, as they have never been replaced. The shocks are fine, it only bounces twice when you press on it. I have a buddy coming over tonight to help replace the Steering Gear box, as its going bad, and adjust the correct ride height. I will let you know what I find.

daxr · August 10, 2014

I haven't seen that problem from a worn out torsion bar, but it is possible. A worn out spring can cause that, though its not very common at all.

In any case, I would start with an alignment, and make sure they begin by setting the ride height. If that can't be set, then the torsion bars would definitely be suspect. If the ride height comes out ok, then there are plenty of other front end parts that wear out on those - idler and pitman arm being the obvious ones. The steering gearboxes on those also loosen up predictably, though its not easy to find someone able to set that up right (I taught myself, having worked in 6 different shops without a tech willing to touch the gearbox except to replace it). If nothing bad is found and it can be aligned its worth doing, and see how it drives from there.

bry21317 · September 9, 2014

Ok, so here is the update to where I am so far on this. I have made quite a bit of progress, and it rides much better, but still not as it used to be.

1) Torsion bars were tweaked in garage on level floor to adjust the car, as they were quite LOW on both sides. They are now pretty even with each other, but the bump stops in the front still are on the Lower Control Arms, which seems to not allow the shocks to work as they should, in my eyes.

2) Stearing gear box was worn out, this had been replaced in 09, and was replaced by Napa parts as it was still under Warranty. Put this on, and the steering is much better now at higher speeds.

3) Rear Springs, I have the LT model, and the springs should have been 16.5" tall, well the old ones that were on there were 15.5" and very bouncy. The shocks could not perform, as they had no room to travel and absorb the shock. I put on 17.5" tall MOOG ones, for the Z71 Models, and the RIDE is SO MUCH Nicer in the rear, on top of it lifting it a bit higher in the rear for sure, like it should look. The garage flat floor to the Fender now is 37" or just over on each rear side now, instead of about 3 inches lower than that prior to fixing the springs.

I have not yet gotten an alignment, but plan on this being a step in the very near future.

I was able to drive the car on the highway this past weekend for the first time in a while, and even at 80, it was much more stable. So It surely was a major step in the right way.

I still have a bit of issue in the Front passenger wheel, seeming like your driving over bumpy ass roads all the time, more of a up and down really fast, that just does not get absorbed. I rotated the tires, and that did not make a difference, so that was not the issue.

I am hoping an alignment should help for sure. As to the Torsion bars, I am close to not having much room to ajust them to lift the front end anymore, and was wondering if Torsion keys would be of value to beable to even out the front/rear height difference? As from putting on the z71 shocks, I now have about 8 inches in the rear between the tires and the fender, in the front it is around 5.5-6 inches. I would like to get it up a bit higher if I could, before adding some new 31 inch tires on it in the next months.

kstruckcountry · September 9, 2014

The control arms are actually supposed to ride on the bump stops. But if you have the bars adjusted all the way and it isn't raising the front the bars may be worn out.

Jacqson · September 20, 2014

Hey,

I have searched and read a lot about the Torsion Bars on these trucks and am not finding 100% if this is my issue or not. So the truck used to ride great, no problems, now for the last 2 years or so at highway speeds it has gotten a lot worse. When you hit a bounce on the Passenger front side, it will get an oscillation from the front passenger side to the Rear Driver side. The two keep springing back and forth until it finally settles down, but at 70+mph that is no fun. I replaced the Front Bump stops the other day, as one was smashed into the Lower Control arm, and the other was damaged. This seems to have helped, but the driver side bump stop is pressed into the LCA. The passenger side one is about 1/4 inch above it. I can adjust the passenger side Torsion bar down, but the Driver side is pretty much maxed out, and my measurements on each of the 4 tires are quite a ways off. There is about 3/4 inch difference between the two Front, higher on the Passenger side of course.

Just looking for some ideas, I will be working on it this weekend and plan to do the Z Trim to get the correct numbers for the Ride Height. Just wondering if it seems that my torsion bars may be worn out, or at least one of them.

Bryan

Those lower cushions (Bump Stops) are supposed to be in contact with the lower bump stop. They are also known as Progressive Dampers and aid in the ride quality of your vehicle. If the bump stop is getting smashed then I would say you need new front shocks and possibly a torsion bar replacement.