I've got a vibration at 80 mph. I've done the following and problem not solved:
- rebuilt rear axle which is a 373 posi
- bought a new drive shaft from Bears which by the way is my 3rd drive shaft
- rebalanced the four aluminum wheels

none of these were the problem.

Can anyone help me ? Any suggestions? Have been working on this for four years. Hoping someone can help

My Z28 is a 383 stroker, 4 speed borg wargner, 373 posi rear

Waiting patiently. Thanks everyone

zapper dan

 

If the vibration is speed related, the thing to look at would the drive shaft and U joints, but after 3 drive shafts this is probably not the problem. If the vibration is RPM related, then the balance of the engine is suspect. Do you have the proper flywheel for you engine? 383 engines can be either internally or externally balanced, depending on where the crankshaft came from. Also, are you sure the engine is not misfiring under heavy load?

 

from 0 to 70 mph the car runs very good. As soon as it hits 72 mph vibration comes in and fades away. Some days when I go for a ride on the highway it does not do it at all. U joints have been changed to better ones. Bottom end of engine is blue printed and balanced. I am thinking of putting in an aluminum flywheel - also thinking of pulling out 4 speed out of car to get bearings and shaft checked. It's not misfiring - got it checked out. When car was stock 350 175 hp the vibration was there. I can't think of anything else. I really don't know what to do next.

Thanks

Dan

 

When you're up to vibration speed, does it go away if you pop the trans in neutral? If it does, you can rule out suspension, front wheel bearings, and wheel/tire balance.

 

I will try your idea. I'l let you know.
Thanks Overdrive. Nice Camaro. Same color as my '79

Dan

 

Check the U joint if it's not that it must be a bearing in the rear end gear box.