Getting rid of rear end shake.

[RED LS1]

My car seems to want to shake it's butt when under full throttle. Whats the best fix for this? I stopped listening to rap music but it still does it under open thottle at higher speeds.

 

[charlief1]

The rear f the car is vibrating, but only under WOT conditions? Have you checkd the tranny mount on it?

 

[RED LS1]

IT doesnt vibrate. It shimmies back and fourth. I know it's common in G-bodys as my brothers car does it and my old MCSS did it as well at the top end track.

It probably needs better sway bar or bag in the rear...Im not sure.

 

[jdpolzin]

Check your lugnuts! Put the car up on jackstands and run it. See if the wheels wobble.

 

[charlief1]

If that's the case I'm thinking either bent axle or bad bushings. Do like Jeremy suggested and put the axle up so the wheels are off the ground and spin the tires. Watch them carefully and see if you've got something bent.

 

[RED LS1]

We just built the whole car on a lift. The wheels spin true as i've spun them at high speeds to test the trans and break it in a bit. The rear tires are actually a tad out of balance and vibrate at 65+ but thats not the problem i'm referring to.

When you get up to high speeds like top of seconed and into third (65-85mph) the back end of the car (the body) dances from side to side. Like it's not stable on the frame. Bushings may be an area of concern but it's a 50,000 mile unabused (well before I owned it) car. My other G-bodys did this also. This one I would like to correct the problem.

 

[charlief1]

Add a location to your personal data. Are you up north?

 

[TurboTnZ06]

My T did this when the stock 180,000 mile G80 posi wore out. It would wobble back and forth left to right under wot even though I was going straight. I put an auburn in, fixed the problem, but I blew that one up. Put another auburn in, blew that up. Put an Eaton in and no problems.

 

[FtCampbellBusa]

Mine is doing the same thing. It only does it at WOT at high speeds. I crawled under and shook everything and noticed that my upper and lower control arm bolts were pretty loose. I am waiting on my new oil drain tube to get here so no test drive to see if that fixed everything.

 

[RED LS1]

I'm in Philly area. I'm going to check/replace the bushings all through the rear control arms.

 

[charlief1]

There's a buch of guys in the Philly area that should be able to help you out with finding the problem. Are you a member of MAGNA?

 

[RED LS1]

I'm not a member. I just got the car together. I have been around these cars for 15 years. I'm sure i'll be able to figure it out with some minor upgrades I was just thinking someone had to have addressed this before with a simple fix.

 

[TurboTnZ06]

Are you running soft drag radials? I only noticed it when I was running drag radials. This was 10+ yrs ago, but I do remember the back and forth wobble from the rear and a new posi cured it.

 

[TRICKSIXPA]

I'm in Delco I think I had a PM conversation with you before. What are you running for suspension Stock? Even with a high milage car you shouldn't be feeling a swaying from side to side. I agree I don't think you have a body bushing problem but I would definitley make sure you check everything before giving your car a pull.

 

[RED LS1]

I'm in Delco I think I had a PM conversation with you before. What are you running for suspension Stock? Even with a high milage car you shouldn't be feeling a swaying from side to side. I agree I don't think you have a body bushing problem but I would definitley make sure you check everything before giving your car a pull.

Yes, we did have a PM conversation. You messaged me after ruining my for sale thread that my $4500 roller was only worth $2500 and I'd be lucky to get that because there not worth anything. Thats when I realized you didn't know anything about cars and I promised to ignore all your further posts. But since I got this far I may add that I still get offers on the car all the time for $4000 rolling.

 

[TRICKSIXPA]

LOL!!! Good luck with the SHAKES!! Some people are so touchy. I was looking for a Roller at the time and I believed your price was high. I winded up buying a whole WE4 after that.

 

[RED LS1]

Some people are so touchy. I was looking for a Roller at the time and I believed your price was high. I winded up buying a whole WE4 after that.

So than it's my fault you trashed my for sale ad and Pm'ed me that my car was overpriced? You never mentioned you were in the market for a roller either. So now the truth comes out you were just trying to wear me down and than buy it for pennys on the dollar?

 

[charlief1]

Knock the fighting off guys. Let's see if we can help figure out the issue at hand here and leave the other issues to PM's or email, ok?

 

[1quick6]

I would wonder about your posi too. Mine used to do that ... under full throttle it would feel like a fish swimming with the tail going side to side.

 

[RED LS1]

Ok so now i'm all over the posi thing. I was wondering why the car would fry the tires for 3 block with only 17 psi and no timing and today I realized it's only spinning one tire

Also the rear whines like crazy on the highway. Funny thing is that the rear was all gone through and fresh from drum to drum just before I got the car together. Guess i'll be paying the guy a visit.