What kind of wobble is this?

  • mizagyu
    mizagyu
    Senior Member
    • 539

    What kind of wobble is this?

    The video doesnt show it well, but the car wobbles left to right in the rear. it does not matter which wheel is spinning, the wobble is the same. ive replaced the diff and its mount, and subframe bushings, rotors, rotated wheels even, but the wobble is still there. only when the weight is down. ive tried jacking it up and letting the wheels spin, but nothing wobbles when jacked up. what could this be?

    the back end wobbles about 2 inches almost, when moving, whether the car is in gear or not.

    http://www.youtube.com/watch?v=yERK_ltFBZ8&feature=youtu.be[/video]] … e=youtu.be

    Project Black Betty
  • Switchback Motions
    Switchback Motions
    Senior Member
    • 705

    #2
    Does the vibration speed up if you apply the gas?
    Were the proper bushings installed? I know there is a bushing that is almost the same as the subframe bushings that could cause the wobble if it was installed.
  • mizagyu
    mizagyu
    Senior Member
    • 539

    #3
    RB20ZR wrote: Does the vibration speed up if you apply the gas?
    Were the proper bushings installed? I know there is a bushing that is almost the same as the subframe bushings that could cause the wobble if it was installed.
    The wobble directly corresponds to wheel speed. Poly subframe bushings used.

    Project Black Betty
  • Andrew84zx
    Andrew84zx
    Senior Member
    • 1110

    #4
    this sort of thing happened to me once,my driveshaft was broken at one of the joints. i would give that a checkaroo
    I hate wheel gap with a extreme passion

    my build
    viewtopic.php?t=2755
    seller feedback
    viewtopic.php?f=18&t=10430
  • FrozenZ
    FrozenZ
    Senior Member
    • 584

    #5
    Andrew84zx wrote: this sort of thing happened to me once,my driveshaft was broken at one of the joints. i would give that a checkaroo
    ^very very much this. If it only happens when the car is in gear, pretty much guaranteed that it's either this or your diff mount is really horribly fucked up somehow. Did you at some point throw poly subframe bushings in with a super-beat original diff mount?

    Check both ends of the driveshaft, don't just assume the tranny end is okay. Also, you can't properly inspect u-joints with the driveshaft on the car.

    I wouldn't be driving it like this if I were you, driveshaft and/or full-on diff mount failures can be super-exciting.
  • G-E
    G-E
    Junior Member
    • 6320

    #6
    Also could be a blown cv joint in the halfshaft
  • mizagyu
    mizagyu
    Senior Member
    • 539

    #7
    If it were the d/s wouldnt he wobble be much much faste than wheel speed?

    This happens in gear and out of gear.

    The car was rear ended long ago bad, but that wouldnt matter too much now idont think.. All bushings are new so that seems solid.. Could wheel bearings cause this? Ill check the d/s anyways.

    Half shafts are new.

    Possibilities?

    Project Black Betty
  • mizagyu
    mizagyu
    Senior Member
    • 539

    #8
    some more info. it doesn't "vibrate" as one would expect. i mean, i can get up to highway speeds, it doesn't vibrate. nothing like an out of balance wheel. but when going slow, 15-35, it feels like the car is wiggling left and right. it did this before my diff swap also, as a friend commented on it when he watched me drive. i have done multiple tire changes and brake changes and rotations, doesn't seem to help any. when jacked up and hubs spinning (wheels+brakes off, engine on in gear) they don't appear to have any wobble. so i'm baffled.

    I'm and engine guy, not a driveline guy lol. but what good is an engine if the power cant move anything?

    Project Black Betty
  • G-E
    G-E
    Junior Member
    • 6320

    #9
    Ahh did you replace your companion flanges when you did the axles? I'm guessing one of those nuts isn't tightened all the way (200ft/lbs) and you have slack allowing the hub to move in and out on one or both sides
  • mizagyu
    mizagyu
    Senior Member
    • 539

    #10
    G-E wrote: Ahh did you replace your companion flanges when you did the axles? I'm guessing one of those nuts isn't tightened all the way (200ft/lbs) and you have slack allowing the hub to move in and out on one or both sides
    ive never changed those axles. just the cv axles.

    Project Black Betty
  • Axel kain
    Axel kain
    Moderator
    • 1221

    #11
    only thing left in the equation is the companion flanges/stub axles and bearings it seems.
    Damn dirty angels....these cars!

    Current Daily Driver - 86 Turbo.
    Under the cover - THE BANANA… that needs to be re-energized.
    sigpic
  • mizagyu
    mizagyu
    Senior Member
    • 539

    #12
    how could they wind up damaged? out of curiousity

    Project Black Betty
  • Axel kain
    Axel kain
    Moderator
    • 1221

    #13
    wait a MIN!!! just got the video to work!

    WTF, looks more like you have a severe engine miss, or it's horribly out of balance. shaking like that sitting still ENTIRELY eliminates the possibility of any suspension or driveline problem!!!!
    Damn dirty angels....these cars!

    Current Daily Driver - 86 Turbo.
    Under the cover - THE BANANA… that needs to be re-energized.
    sigpic
  • mizagyu
    mizagyu
    Senior Member
    • 539

    #14
    Axel kain wrote: wait a MIN!!! just got the video to work!

    WTF, looks more like you have a severe engine miss, or it's horribly out of balance. shaking like that sitting still ENTIRELY eliminates the possibility of any suspension or driveline problem!!!!
    nah man. engine runs a charm, passes smog no problems. cant even tell its runnin when its on. the movement and sound you hear is the tire spinning on snow, car sitting still. hence betty saying door is open.

    if you look close near the end you can see my right wheel spinning.

    Project Black Betty
  • G-E
    G-E
    Junior Member
    • 6320

    #15
    The exhaust plume does suggest you have an uneven idle, but the audio isn't very good, you need a better camera