Proper ride height and torsion bar adjustment

Discussion in 'General Chevy & GM Tech Questions' started by Family Force 6, Jul 14, 2013.

  1. Family Force 6

    Family Force 6 Rockstar 100 Posts

    I hope I'm OK starting a new thread, though it's related to my shock absorber failure post it is a different/specific question.

    I've had 2 failures of my Monroe Reflex monotube shock within the last 2 years, the most recent on a road trip. When replacing the shock today (driver side) I noticed that it would not line up on the bottom mounting bracket (the shock was too short- just by a hair). This got me thinking that maybe the shock was failing because it was getting over-extended and my ride height needs to be adjusted.

    I measured and determined that indeed my driver side front was about 1/4" higher than my passenger side. It also appears that my front is higher than my rear (as measured from ground to top of wheel wells).
    A few questions:
    • How do I determine proper ride height for front? should it rest against the bump stop on the lower control arm?- this is for stock, no lift
    • It appears that my rear end is uneven as well- could the front torsion bar adjustment effect this?
    • Should torsion bar adjustment be included in alignment?

    I searched the forum and Google and couldn't really find information on proper ride height- any help would be appreciated!
     
  2. Family Force 6

    Family Force 6 Rockstar 100 Posts

    Any help? I think the shock I just replaced blew again! I need to get this straightened out. Maybe I should just take it to the dealer?
     
  3. adampaul1964

    adampaul1964 Epic Member 5+ Years ROTM Winner 1000 Posts

    Torsion bars allow for a lot of adjustability in ride height and so long as your using the specific shock for your vehicle variances in torsion bar adjustment should not cause shock failure. Most chevy's do "lean" a little in the rear, mine is almost an inch lower on the drivers side ( really noticeable since I lowered it! ) but you should try to adjust the front so it's even. I'm not familiar with your other thread, but from this description it does sound like your shocks are too short.
     
  4. Family Force 6

    Family Force 6 Rockstar 100 Posts

    I've put the correct shock on- verified it when I picked up the replacement this last weekend. I think I'll just try lowering the driverside by a 1/4 " and see if that does it. I still would like to figure out how the torsion bar should be adjusted. I've read about the "Z height measurement"- does that have anything to do with it?
     
  5. Family Force 6

    Family Force 6 Rockstar 100 Posts

    OK, spent a bunch of time researching this and just wanted to update the thread.
    GM does have a recommended "trim height" or "z" height. This is determined by measuring from the middle of the lower control arm to frame pivot bolt to the bottom of the steering knuckle(you can also measure from each of these to the floor, then take the difference). You must be on a level surface. For my 99 Suburban the factory trim height is 4.5". Additionally I read that the front should be adjusted so that vehicle almost touches the rubber bumper "jouncers" on the lower control arm.
    I took it back to the shop that did my alignment a few weeks ago and paid them to adjust the torsion bars down and re-check the alignment (there was about an inch of clearance between the lower control arm and the jouncer). The suburban rides MUCH nicer now, and I got my 07 rims mounted too. It rides awesome now!
    IMAG0594.jpg
     
  6. foca ruiz

    foca ruiz New Member

    interesting. my 2001 is an ex-forestry vehicle (painted pastel light green), and it's been set to touch the "jouncers", which I always thought was odd. I turned them a few turns towards up, cause my 5-year-old jouncers are already in pieces. But, maybe when I put the new ones on, I should go even higher.

    Also of note, I read somewhere (maybe my carfax) that my truck came with a factory lift (which I always guessed was a body lift, not a suspension lift).

    Did you read that stuff in the chevy factory repair manuals?
     
  7. Family Force 6

    Family Force 6 Rockstar 100 Posts

    I can't remember where I found the info now, but I wouldn't have posted it if I didn't trust the source. I did determine that the Monroe Reflex shocks are JUNK. I finally replaced them with Ranchos and haven't had any issues since. I agree that adjusting them so they are at least just above the jouncers and not resting on them is a good place to start.
     
  8. wildncrazyguy

    wildncrazyguy New Member

    I know this is older thread, but curious about the jouncer height mentioned. Almost touching is what I hear, but does that mean actually touching in the cavity? Are mine adjusted too high? I can't ever seem to find any good information on this. Thanks in advance.

    My 98 burb rides like crap even with new Bilsteins and new font end components installed. This is an older pic with original end links which were also replaced in addition to sway bar bushings. Still rides like it feels every minor bump in the road. If on smooth pavement, nice ride.

    IMG_1555.JPG
     
  9. tbplus10

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

    The jouncers or bump stops are designed to stop the suspension from bottoming out metal on metal, they give a slightly less jarring impact when this happens.
    Older vehicles can be found riding right on the bump stops sometimes due to spring wear/degradation, the spring looses tension or collapses (depending on torsion bar, coil, or leaf) due to metal fatigue.
    The correct repair for a degraded spring would be replacement, but for a variety of reasons this isn't always possible. Adjustment for torsion bars or addition of coil sepparators or add a leafs for this type springs is usually the easiest or most economical fix.
    Unfortunately when a spring wears and needs adjustment it will only continue to sag more and more as time passes, and eventually replacement will be the only option. Most manufacturers recommend a ride of 1/2" to 1" above the bump stops, but this ride height isn't all inclusive to every vehicle, just an average.
     
    Loose Screw likes this.
  10. wildncrazyguy

    wildncrazyguy New Member

    Thanks for the info. I cranked by torsion bars up a bit, but it really rode like crap, so I lowered them back down to where they were, had alignments done as well. By looking at the picture, are the jouncers at the proper height or do you think I need to lower still into the cavity to get to the 1/2 inch or so before touching? My 1998 Z71 sits much higher, but I think the suspension is a bit different on the Z71, even though same components.
     

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