Hi, i'm new here...and i was needing a little help with a problem I have with my camaro.
It's an 83, Z28, t-top, 383 stroker, TH-350 tranny.....

The problem I have is that at any speed over 50, the whole rearend of my car shakes....and starts to shake my whole car...it's kind of like a vibrating....I've put on new shocks and struts, had 2 different people drive it besides myself, who said they didnt know what could be wrong with it...
So I was wondering if any of you have ever had this problem, and if so, what was it, and what did you have to do to fix it?

Thanks in advance, i appreciate your time.

Dave

 

Driveshaft out of balance, wheels out of balance, bent rims, bad tires (thrown belts), Where else do you want to start?

Have someone follow you when it starts to happen and have them see what's happening. Bad tires or bent rims are very easy to see.

 

I just picked it up from the shop from having an alignment, the tires are basically brand new...and the rims looked okay when Ihad the tires put on, so i wouldnt think it would be those.
I was thinking it could possibly be the driveshaft....whenever i punch the gas, it makes a kind of knocking/smacking noise from under the car for just a split second..

Do you think maybe it could just be a bad U-Joint????

Thanks for your quick reply.

 

Put it up on stands and check for something loose... Bolts fall out of something... Maybe the tork arm that attaches from the differintal to the transmission.. If so the differentail will change angles drasticly....Check the trans mount.... Check the U joints... When my car was new the bell housing bolts all feel out even ..

 

I suggest you listen carefully to the knocking/smacking noise on acceleration. It may be a broken transmission mount. This is fairly common (I had this problem on two of my four Camaros), and fortunately, fairly cheap to fix (about $30). With the car settin still, put it in drive without moving, put your foot on the brake, and hit the accelerator (you may need to do this rolling down the street slowly so the brakes don't absord the torque). If you hear a thud around the transmission hump, it's your tranny rocking and hitting the underside of the body. This may not necessarily be your problem. As the others have suggested it could be an out-of-balance drive shaft, bad universal joints, etc. But, the tranny mount is a common culprit that's worth investigating.

 

u-joints or d/s mounting to the rear end.

 

First thing you need to determine: is it at driveline speed or wheel speed?

Brand new tires is no guarantee that one is not separated. Happens all the time, especially with cheaper brands of tires.

Put the rear of the car up on jack stands, put it in gear, let it drive itself at idle like that, watch the wheels; check for runout in the wheels, lumps in the tires, etc. If a wheel appears to have runout, swap them to the other sides; if the runout stays on the same side you have a bent axle.

If it's at driveline speed, check the U-joints, drive shaft condition & balance, extension housing bushing int he trans, pinion bearings, pinion yoke, drive haft angles at the trans & rear end (should ideally be nearly the same, about -1½° at both places).

 

Another way to narrow down where the vibration is coming from...

Get on the highway , get up to a speed where it starts to vibrate. Now put the tranny in neutral....does the vibration go away or does it stay?

If it goes away, look towards something in the drivetrain...

As for tires...CHECK 'EM!!! I had rear tires on my IROC that looked fine....replaced 'em with some nice BFG KDWS' and my strange shaking between 65-70 went away completely. Car is glass smooth up past 100 mph now.

Where is the vibration felt the most when driving? Can you feel it in the seat? Thru the steering wheel? This will also help narrow down problems..

As for the driveshaft...try removing it and rotating it 180 degrees then reinstalling...if the vibration changes, you've more than likely found the culprit...


HTH