soulvoid86

Hello,

So where do I begin.. I have a 98 Firebird V6 with about 95k on it. Motors strong, trans is strong, and drive line is strong.

About 2 years ago, I blew the rear. Broke the pinion rod in half, which then caused everything else to just yoke up. Needless to say, I rear built the rear. Put a 3.73 posi in. The rear is great, gave the car a hell of a lot more pick up, and the posi is just fun. I also then put a set of American Racing rims on, with 10.5" rears and 9" in the front, 17" rims, not the 18". Also put Sumitomo tires that are rated up to 183mph.

Now to rebuild the rear, I ended up having the drop the axle, not going to get into that because the story as to why I had to do this is irrelevant.

After the rebuild, we put the rear axle back up, torqued everything down to spec, lubed up all the bushings and replaced the sway bar links. But for some reason, the rear end wobbles like hell now. The struts are good, the car isn't sagging or anything like that, doesn't bounce up and down or anything. However, the car wobbles side to side horribly, to the point that I can't take it on the highway over 55 or it feels like the rear end is going to whip out. Bumps have became extremely rough, and there is a loud clunk.

I have been in school and working full time, so I haven't had a chance to tear anything apart to check bushings or anything, with the traction bar or anything, but I did replace all of them on the sway bar. Like I said, everything is torque to spec that the Hanes has listed. Other than the posi and rims/tires, this car is completely stock. This never did this before I dropped the axle. Only things I disconnected were whats necessary to remove the axle, no bars were completely removed.

Any advise as to what to check?

I might be able to get pictures from the orginial teardown in a little bit, to show what was still attached and what was removed.

Many Thanks

soulvoid86

Also, when I rebuilt the rear, all bearings and seals were replaced. Only used parts were the axles themselves, which were fine.

soulvoid86

It does this when your on the throttle or not, it has nothing to do with throttle, I don't believe anyway. Also, it seems like when I hit about 65-70, it feels like a tire is off balance, but I've had the tires checked by 4 different garages. There's also no body roll either, the car sits completely flat going around a corner. I can take very sharp corners at 45 full throttle, and the new tires just stick to the road, but if there is any type of bump, the car will fly all over the place.

1320Chicken

iTrader: (4)

Long ago I installed a set of bolt in control arm brackets and mine would do the same thing. I decided to weld them and problem solved. From my experience it sounds like something is loose allowing it to shift from side to side.

Just dumb question but was the suspension loaded when you torqued everything? I'd look at control arms, panhard, and tq arm bolts and bushings one more time just to be certain nothing is loose and none of the bushings are shot. I don't know if uneven tq or misslignment of the sway bar would cause this or not.

SSellers

Make sure you didn't do something that would be my speed which is leave the c clips out so the calipers are holding the axles in. Also put a micrometer on each tube and check the runout of your axles.

soulvoid86

Hmm, thats def. something for me to look into. When I torqued it down, I had it the back end of the car on jack stands sitting on the pinch point on the body, no tires on or anything like that. I have checked all of the bolts and bushing 3 times now, and everything is fine, a little worn, but not to the point that it should be causing this.

I did torqu the sway bar a little past spec (by like 2-3lbs) and that seemed to help a bit.

soulvoid86

Everything in the rear is fine, I've pulled the cover off and checked everything when I changed out the break in fluid. As far as I could tell everything seemed fine. The c clips are still there, and the axles are not loose at all.

I don't have a micrometer, so I can't do that, but the shop that I had shim my rear, said that the axles and the actual rear it's self is fine. I know that I need to have my gears re-shimmed, because they do have a small amount of slack, but simply from it being broken in. The new chunk and gears only have about 2000 miles on them.