Vibration during acceleration

[williillii]

Hey everyone, I'm having an issue with my 95 gst. It has a bad vibration from about 35-40mph up to about 60-65mph. It seems to come from the front left side of the car, the d/s mirror vibrates and it shakes the window in the door alot. I've replaced the following trying to hunt it down.

lateral control arms
curved lower control arms
inner tie rods
tie rod ends
upper control arms
axles
balanced/swapped tires

I've been all over the suspension shaking it with my hands and beating it with a rubber mallet, having a friend turn the wheel while I pull on the tires, etc etc. and every thing seems tight except the oem swaybar bushings (D shaped ones) are a little squishy.

Other things I think might be related, when I back out of the driveway reverse gear, clutch pressed in, rolling backwards) as soon as the wheel rolls back it makes a clunk sound once. Then under moderate braking right before the car stops it clunks once also. And if I put the car on jackstands in gear, and spin the wheels there is a bit of slack (1 inch or so) and a clunk noise before the other wheel starts turning. Is that normal or maybe my axles are incorrectly installed?

I'd appreciate any insight! Thanks!

 

[notverygood]

Does it go away if you turn the car abruptly at speed? try left, and right. Depending on if it goes away it could be a wheel bearing. Pick the car up in the air, put something near each tire (or better yet-get a gauge) and check for runout.

 

[williillii]

Hmm, sometimes when I come out of a turn (90* intersection) and gas it it feels really smooth, I let off, and do it again and it starts vibrating again. I've done the standard "shake the wheel at top and bottom/ side to side" test and it seems tight. Is there a better way to inspect them? I guess a runout gauge like you say?

 

[rEclipserGST]

When is the last time you replaced the Crank Pulley (harmonic balancer)? That could cause vibrations even during idle.

Alignment
Blown Shock
Bad Strut
Damaged Spring
Crank Pulley

Check or replace those.

 

[rlacasse1]

the way you said it clunks when you hit the brakes makes it sound like you have a bad cv shaft in the front. have you checked it. when they go bad you can hear them make a clunk noise when you take off and stop.

oh i see you changed axles. my bad. when you changed it did the vibrating change or the clunking change at all. also, out of curiosity, can bad motor mounts cause this.

 

[rEclipserGST]

Yes motor mounts can as well. That was an overlooked possibilty and can be fixed by throwing poly urethane mounts everywhere

 

[williillii]

^I replaced the two mounts with polyurethane bushings, and the roll stops with 3m windo-weld and the poly inserts.

Nothing really changed when I did the axles. I will check the harmonic balancer.