How to know if bump stops are bad?

Discussion in 'General Chevy & GM Tech Questions' started by Tim Tholen, Nov 19, 2011.

  1. Tim Tholen

    Tim Tholen New Member

    I have an 02 LT Suburban, 4wd with 130k on it. The ride had gotten hard recently, and I am looking for things to replace. The shocks are less than a year old, so I know it's not that. I am taking it in to have the ball joints looked at. I have the front and rear sway bar bushing and link kits from Energy Suspension on the way. With all that, I am trying to find information about the bump, or jounce, stops. How do you know if they need to be replaced. I went by the dealer and grabbed one to compare against one that is [on the truck and they appear to be in the same condition, though I find that hard to believe after 130k miles. Anybody here have any experience with them? Anything else I should check while I am at it?
  2. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    Pretty much, if the bump stops are still there, they're fine. The only real reasons to swap out bump stops are if they fall off or you do a ton of off-roading and put a lift on or things like that. Ordinarily, the suspension should never make contact with the bump stops.
  3. phoebeisis

    phoebeisis Epic Member 5+ Years 1000 Posts

    Crawdaddy is dead on I think.
    Bumpstops never cause a hard ride.
    Your suddenly stiff ride is a real puzzle.
    When shocks wear out the ride usually becomes a bit sloppier-but not stiffer.
    Now increased tire pressure or new tires- say going from P rated (passenger car) to LT (light truck) will make the ride a bit stiffer.
    In general s stiffer ride is because you did something or maybe the weather/temps suddenly changed- not because something wore out.
    1)Check tire pressure?
    2)Did you change your tire type? P TO LT
    3) Are those shocks OEM or OEM spec or are they some sort of heavier duty performance shocks?? If they are some sort of aftermarket that implied a better controlled ride-that usually means stiffer. Might be some combo of the new stiffer shocks and increased tire pressure finally annoying you enough to notice it??
    4) Did you take some weight off your truck-says you used to carry something in the back and finally removed it?
    5) Or are you running with a nearly empty tank- 40 gallons of gas is 240 lbs??
    6) Has it suddenly gotten colder in KC?? Maybe 70 degrees to 20 degrees?? That will make shocks stiffer until warmed up-a few miles I guess.
    7) You haven't changed anything to do with the suspension other than the shocks- right?? And that was 1 year ago?? Wonder if these shocks are for some reason more temperature sensitive??? Cold increases the viscosity of the shock fluid in the shocks-makes them stiffer until warmed up.

    This is a real puzzle-interesting. Wear in the suspension doesn't make the ride stiff-unless a shock suddenly seizes ?? I had motorcycle shocks rust up but it sat in the rain-unused-for 20 years.
    I'm betting it is something you changed or the weather-maybe the shocks, but that was one year ago.
    I could picture very cold weather making shocks stiffer until warmed up, BUT KC isn't that cold, is it?? You haven't suddenly gone from 70 degrees to 25 degrees have you?? That might make it stiffer until wared up- 3-4 miles or so??

    I had a front antisway bar bracket break- it cause a thump sound when going over bumps-can't remember it making the ride stiffer??

    This is a really interesting problem- keep us posted. You "know" your truck, so I'm sure something has changed dramatically enough for you to make a trip to the dealer.

    Keep us posted.
  4. tbplus10

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

    If your hitting the bump stops at all the problem is more likely to be worn springs, torsion bars, etc, your possibly even bottoming out the shocks which would account for some of the roughness too. Remember shocks dont support the truck unless their a coilover type, they only suppress the rebound and dampen the suspension action.
    Unless you have pnuematic or hydraulic aftermarket bump stops theyre just rubber bumpers, their considered bad when they fall off.
  5. Tim Tholen

    Tim Tholen New Member

    The shocks are whatever Firestone put on, not their base but one step up. Weather hasn't changed, still mid 60's here. I don't haul anything other than my rather larger hind quarters. I did go out and check the tire pressures and they were about 38, so I backed them down to 32. How would I check the torsion bars? There has been a groan under my seat anytime I go over speed bumps or humps in road and the suspension moves. I was actually thinking about the torsion bars the other day and wondering how I would tell if they are bad. I will have them check the shocks when I have the ball joints inspected and see if something is wrong with them.
  6. tbplus10

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

    The best way would be to measure the ride height of a truck similiar to yours, the problem is most trucks similiar to yours are 9 yrs old and probably suffering to some degree from the same issue I suspect yours is, sagging suspension.
    Suburbans are heavy vehicles it wouldnt surprise me one bit for the suspension to be worn out. Look at some of the on-line repair manuals maybe one of them has frame to ground measurements that'll help determine if this is the problem.
  7. aloxdaddy99

    aloxdaddy99 Epic Member 5+ Years 1000 Posts

    I agree with the things phoebeisis said. I am not familiar with the torsion bar suspensions but if it has a bushing of any kind look at it and see if it is there if it is supposed to be. When you had the new shocks installed did you ask them to crank up the tbars at all? This will effect the ride also. How many miles are on the shocks? Have a friend push down and let go of the truck at each corner. While they are doing that look at each shock to make sure they are cycling like they should be. I know you said the shocks are new but one may have malfunctioned.

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