2000 SIlverado resonance shake

Discussion in 'Lifted & Offroad Suspension' started by ukrkoz, Feb 5, 2008.

  1. ukrkoz

    ukrkoz Rockstar 100 Posts

    ok, i have 2000 Silverado with an odd issue.
    1. it is not repeatable, it happens when it wants to and is not very often, but every time scares the hell out of me.
    2. first time it happened, i hit a moderate bump in the left hand freeway turn, at about 65 mph. all at a sudden, the whole front virtually went up in the air and into uncontrollable up and down and side to side shake. was pretty major. it felt like front wheels bounced off that bump and resonated. total chaos.
    3. it repeated itself on the same bump maybe twice more, so i learned either not to go fast over it, or keep wheels straight
    4. same resonating shake occured on several more occasions on different roads, every time fater hitting a bump in the road.
    5. today, it did the same two times in a row, on a straight stretch of freeway, after slight bounce.

    every time this happens, it's pretty bad, car shakes and bounces vigorously, steering wheel goes left-right, front bounces up and down. truck has 76K miles on it; i bought it with 58K on; first time it happend about 4 mths ago.

    otherwise, it drives smoothly, just kind of is "snaking" left and right at hwy speeds, but usually that's when you have those groves in the hwy from long use.

    i do not like it. every time this happens, it feels like car will flip over. every time steering wheel is in slight turn. slamming on the brakes fixes it, but i am afraid someone will rearend me for this.
    i have 2 theories: shocks and stabilizer bar. nothing's hanging lose, no leaks under the car. shocks feel fair for truck. somehow i have that feeling that it's just made this way, and i hit it in a "sensitive" way and it goes into that resonating shake. also, lord save my wife drive it and this happen.

    any ideas?
  2. unplugged

    unplugged Epic Member 5+ Years 1000 Posts

    Take it to your mechanic and have at look once it's up on the lift. Pretty easy to diagnose front end issues. The question will be do you want to handle the work or have the shop take care of it. Look for worn tie rod ends, ball joints and leaky shocks. Uneven tire wear can also point you in the right direction.
  3. FireRed

    FireRed Rockstar 100 Posts

    Good possibility it is the pitman arm, if you are handy it is a fairly easy fix. You can usually feel the up and down motion with the truck jacked high enough to slide part way under.

  4. ukrkoz

    ukrkoz Rockstar 100 Posts

    thank you. i can do same or better than many shop mechanics. was seeking advice as i simply do not want to disassemble too much of steering geometry components.
    as of today, it is down to 3 culprits: pitman, idler, and damper. idler arm is attached to a large cylinder that looks like some sort of hydraulics, i figure it's damper.
    all parts are easy available from local stores. unfortunately, i got sprained muscle in my left shoulder, so going "under" will have to wait for maybe a week. 3 day weekend's coming, that should do it.
    i know it's not tierod ends, as there is no shimmy or vibration while braking. magnitude of whobble does not sound like tierod ends either. i am almost positive it's damper, maybe damper and idler. better say - ball joints in them

    anyone ever tried to press balljoints out of idler and replace them? it's too thick a metal to get bent or warped, and why pay for the whole entire arm, if it's 10 bucks ball joint that needs to be replaced?

    CORRECTION: large cylinder i thought was damper, is simply idler arm housing. all it is is 2 bearings for idler arm stud inside aluminum casing.
    Last edited: Feb 18, 2008
  5. cobrakiller8402

    cobrakiller8402 New Member

    i have a 00 silverado and am having the exact same problem. please post up when you determine the problem,
  6. ukrkoz

    ukrkoz Rockstar 100 Posts

    what you need to do is to get yourself suitable jackstands and hydraulic jack
    i place hydraulic jack under a crossbar in the lower control arm, next to lower ball joint
    jack it up on either side and place jacks under the frame rales, high enough for tires to stay clear off the ground
    after everything is secured in place, and you have parking brake engaged and a block under rear wheel, unlock steering wheel.
    grab the bottom of the front wheel dead on the center and try to forcefully move it back and for. if you have movement, it's your lower ball joint. repeat the same with uppermost part of the wheel - that's your upper ball joint.
    grab wheel on the sides, across the center, and try to move it like as if you are turning it. if you have play in it, it's either your tierod ends, or idler/pitman ball joints. mine had pronounced play with this check.
    locate your tierod and relay rod. you will notice that there is a joint between tierod and relay rod, with rubber boot on it. grab tierod and relay rod and try to spread them apart. chilton says that if there's more than 1/32 play, relay rod needs to be replaced.
    grab tierod to relay rod junction and push it up/down. if there's play in it, tierod end needs to be replaced.
    the last 2 tests are described in chilton manual, i strongly encourage to buy one.
    remove plastic underpan, 15mm head bolts x 5; you may not have one. ask someone jog steering wheel left-right; flash light at idler and pitman ball joints. idler joint in my case had clunk and you could see relay rod moving slightly ahead of ball joint itself. vehicle is wide enough to pinpoint such a noise to either joint.
    so far, i had 2 observations: horizontal play in the wheels and clunk/displacement in the idler ball joint.
    i have repalced idler arm. $69.90 schucks; you'll need their "front end tool kit #3", 21mm, 15mm, and 17mm sockets, long 1/4 socket wrench, matching extension, and i believe 22mm spanner. i used large crescent wrench to stabilize nuts on idler arm casing bolts, when removing them. c-clamp will be needed either.
    i do not know what you'll find for your truck. idler replacement is virtually 15 min rookie job. get truck on ramps for that, will give you much better access than jackstands and safety is higher.
    the only trick i did was to jamm idler ball joint into relay rod with c-clamp so it does not turn. i disconnected idler arm from housing in a vise. oh, yes, and you'll need suitable allen wrench. idler arm stud in housing has allen wrench center hole in it, to stabilize stud while removing the nut. it was all very rusted, and even with much penetrating oil applied, nut held well. i had cheat pipe on the allen wrench, and was quite sure i'lll snap it. so i went for proper size torx socket head, 3/8 extension and cheat bar. that did the job. all nuts on this job are pinch nuts, so they do not release/tighten easy.
    good luck, and get chilton, well spent 15 bucks.
    i have, also, kyb steering shock coming this week. it's simple bolt on job. i feel it should greatly reduce any horizontal play and vibration in the steering. after close look at the design, even with brand new everything, there still will be some play, as it has 6 joints and relay rod is so long that it will inavitable bend some with side forces applied.

    editied next day.

    ok, i had the truck on jackstands one more time. just to make sure. right side does fair. left side has a problem: it has vertical play with light clunking noise when the wheel is moved back and for vertically. very little of play horisontally, no noise.
    judging by the noise location, clunk is coming from the hub. i had my fingers on both upper and lower ball joints, while rocking the wheel, and i could not feel any play or knock in them.
    shake did not go away completely, it changed. now it's much less pronounced, and is defnitely coming from the left front side, i can feel it in my left foot.
    i had prybar between upper balljoint head and control arm, and i could not pry the head up or down or in any other way. on my book, there
    s nothing wrong with that joint, otherwise, i should be able to move it with prybar.
    my assumption is - it's hub assembly. i'll have wheel/braske caliper removed, and will try to yank on hub assembly itself to reproduce the play. if that's the case, no big deal, only money. they run around $150, removing it should be very easy. i'll have to buy an oversized socket, the largest one i have is 32mm, and it won't fit. anyone knows what size socket could it possibly be? i'm figuring will take me maybe 20 minutes to do the job.
    Last edited: Feb 19, 2008
  7. ukrkoz

    ukrkoz Rockstar 100 Posts

    got it fixed

    ok, i have it fixed.

    replaced hub assembly today.
    tools required: 15, 18, 36 mm sockets; 15 mm box wrench; 6mm hex wrench; mallet; prybar; cheat pipe; 1/2 inch drive for 36mm socket; quality greese. rag to wipe parts and dirt. torqx socket for brake caliper. 36mm socket was rental from schucks, free.

    job is very easy. once jackstanded, supported securely, remove the wheel, brake caliper, caliper bracket. hub assembly has large cap pressed into hub, covering driveaxle nut. i simply used flathead screwdriver and mallet to slowly hammer/pry cap's edge from the hub, and then it just goes.
    wedge prybar between the studs so that hub does not spin, and break driveaxle nut lose. i had to use cheatpipe and i am very strong. central nut is pinch nut, so it took a lot of effort to remove it to the very end.
    using hex wrench disconnect ABS sensor from the hub. using 15mm box wrench remove 3 bolts holding hub to steering knuckle. helps to push on driveaxle in, that clears bolt heads for wrench or 15 mm socket.
    hub simply came out. i stripped one bolt head, it's the 2nd bolt on this truck that has very soft head and strips easily, the other one is transmission drain one. i am not worried as i have titegrip sockets, so i can always remove it again if i need to. be careful and push driveaxle in, or you can pull it out and seperate u-joints. lubricate splines before installations. mine looked way overheated.
    assembly was reverse to removal. do not repeat my mistake and make sure that splash guard faces towards the engine, or you'll have to redo the job, as brake rotor won't fit.
    total time about 25 minutes. costs involved: $165 hub, schucks, 2 yr warrenty; assembled in mexico from american parts, parts were marked made in usa seperately. $$ saved: $60 les schwab labor; napa wanted $233 for hub, les schwab - $223.

    aftermath is very pleasant:
    1. have no horizontal or vertical play in that wheel anymore
    2. i purposefully drove truck today over 2 spots on local fwy where i routinely had shake. no more.
    3. steering wheel had noticeable sidewise play in it while driving on regular roads before; none now, it's stirdy.

    my passenger front side is sagged and ride is, generally, like on stilts. 80K miles takes its toll on shocks, so i have KYB monotubes ordered and will be delivered next week. will have them on before weekend.

    that's it. :party::party::party::great:

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