05 Silverado suspension improvements

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by anven, Aug 2, 2012.

  1. bazar01

    bazar01 Epic Member 5+ Years 100 Posts

    Yes, I raised it by cranking the torsion adjustment bolt. I basically screwed the bolt in. I still have about 1/2" of threaded section on the bolt adjuster. I think the torsion bars are getting soft and twisted over time and causing the front to sit lower. The ride has improved a lot, but I still plan on replacing the 160k miles shocks with factory ones even if my front tires were not even bouncing. I figure, the ride was pretty good with the factory shocks and lasted this long so I am going to use factory shocks.

    Oh, on my 2011 Silverado, I did some front and rear ride height measurements while it is still newer and wrote it on the service booklet for future reference, so I don't have to ask for original ride height measurements 10 years from now once the ride start getting stiff or soft.
    Last edited: Aug 3, 2012
  2. bazar01

    bazar01 Epic Member 5+ Years 100 Posts

    When I raised my Suburban with torsion bars by 1 inch, the bump stops did not totally get a full gap from the lower control arms, but the ride has improved a lot. The bump stop geometry will not allow the bottom section to sit parallel to the lower control arm. It was still touching the control arm but just barely on one edge of the bump stop.
  3. anven

    anven Member

    Thanks alot - this is good to know. I will try this weekend and report back. Also, I have been looking at aftermarket bump stops - seems like a common item to replace and they come in all sorts of heights.
  4. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    Sounds like your torsion bars are worn.
    It shouldnt be sitting on the bump stops, those are meant to stop a metal on metal hit when the suspension flex's to far.
    You can crank the torsion bars up some but keep in mind even though their worn cranking them up might make things stiffer, I suspect if you go just a little higher you might find a happy medium where your not hitting the bump stops and the torsion bars arent to stiff, but the real fix is probably gonna require new torsion bars.
    Shocks dampen the ride, basically slow down the suspension cycles so it doesnt bounce after the initial impact. They wont lift since you arent using a coilover style and if they do lift then that creates a whole new issue because your riding on the shock which will probably end up failing due to the extra weight riding on it which it wasnt designed to support.
  5. anven

    anven Member

    I agree - so will proceed with baby steps to crank bars a bit, perhaps try getting shorter bump stops (as some forums suggest) and if this proves to be helping, get new bars and drive happily.
    I have couple questions -
    1) Should the front and rear heights (I believe P and R heights) be close? When adjusting the keys, do I want to get the front and rear more or less "level"?
    2) Are there any aftermarket torsion bars that offer better performace and/or price? So far GMpartsdirect seems to be the only source of torsion bars that I could find.
  6. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    When new the rear suspension is normally a few inches higher than the front, this is to acomodate load capacity.
    I dont know how worn the rear suspension on your truck is but I would suspect it's still sitting higher than the front, if your not using the truck for hauling large loads then the front/rear height bias is more of a personal preference.
    Probably the best bang for your buck is factory torsion bars, there are a few lift manufacturers that sell "lifted" torsion bars but the problem going that route is they normally stiffen the ride while lifting the suspension, so since you want a smooth ride I'd stick with factory, also aftermarket torsion bars normally tend to wear a little faster than factory ones, some of this is due to the fact they are under more stress lifting the truck but also they use a different tempering method for the steel to get the spring rate desired.
  7. rileyjr16

    rileyjr16 Epic Member 5+ Years 1000 Posts

    I'm about to go crank my bars back up. I cranked them down to try and find that happy medium but found an unhappy hell. Seems like the ride is better on my truck with them turned up. Plus I'll relieve some pressure in my tires down to 35psi
  8. anven

    anven Member

    So..... this is what having a working suspension feel like! Cranked up the torsion bars (1.5 inches), replaced shocks - truck rides 100 times better. Its not a caddy yet, but not a wagon either. Next on the list - new torsion bars, new tires and alignment.

    Thanks to all for help and advice.
  9. paracutin

    paracutin Rockstar 100 Posts

    This thread has some really good, technical info on torsion bar suspensions.

    I was not experiencing any ride issues but I decided to see where my front end was sitting. Turns out that the bump stops were just barely touching the lower control arm and the right side bump stop is ripped a bit. I cranked the torsion bars about 1" (4 full turns of the bolt). The ride is stiffer and a bit more bouncy. Rides like my 04 F250 did. Reminiscent of a buck board wagon. We'll see how it does when I hook the boat up. I am going to replace the bump stops and probably crank to torsion bars back down a bit.
    I should also note that I have 265/75 16 Wild Country MTX "E" rated tires. Max pressure is 80lb. I run all four at 65lb. I might try taking the fronts down to 50lb-55lb before backing the torsion bars back down. I like the look of the truck when it is closer to level.
    Last edited: Aug 6, 2012
  10. bazar01

    bazar01 Epic Member 5+ Years 100 Posts

    Is 65 psi the recommended tire pressure on the tire pressure decal? I think lowering your tire pressure first is a good idea.

    You are not changing torsion bars so it should have the same spring rate. You just shifted the loaded axial position of the bars and the truck is the same weight load. I don't think raising the bars will stiffen and make the ride bouncy. Bouncy ride is a damping issue and maybe caused by a weak or worn shocks. Torsion bar do not perform any damping function.

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