The Stovebolt Site Forums The Shop Area Driveline '36 RD chevy (ton&half) vibration in drive shaft

Please someone out there help me! Been on this for 4 months! Truck has 2 drive shafts-support in middle with u joint, bearing and bushing all replaced. rear drive shaft replaced along with bushing and pinion bearing. Front u joint attaches at tranny also replaced.The only thing I haven't replaced is front drive shaft! When I have it on jack stands it seems to make a lot of noise in middle of drive train. Do u joints have to be aligned or balanced with drive shaft? Also replaced coupling on rear shaft which joins short section to a large bearing and pinion bearing going into rear end. Please help.

Have you checked the alignment of the driveshafts at the support bearing? Sounds like something is out of wack.

Thank you for answering. No I have not checked the alignment. I am totally ignorant of these kind of things. I can take them apart and reassemble but not totally understand them. How would I go about doing this? Do I need to take it somewhere to have it done?

You might have two issues. There is a "slip" joint that allows for length changes as the rear end goes up and down. And there can be a balance issue when all the parts have been changed out. My bet would be on that slip joint as worn and loose. Find a good drive shaft shop. They usually do third members as well and have that drive shaft checked out.

Thanks so much for the feed back. I have taken this drive line apart 3 times and the only thing that might be a slip joint is a coupler that connects the rear shaft to a short shaft that houses a big bearing and the pinion bearing at the very end inside the differential. I also replaced this coupler. Do these garages check for u joint alignment? All the noise seems to be coming from where the two shafts are joined by a u joint, bearing and bushing. Thanks for your help.

Yes and, you might need to align that carrier bearing as well. I had one in a 67 C20 that was cocked a bit. The mount holes in the frame had taken a hit some time and the flange was tweaked. A little time with a burr grinder and all was well. Go figure.

Thanks so much for your help. I called a place in Austin that balances drive lines and he told me to bring in both drive shafts with u joints and they could fix me up. I will keep you guys informed in a couple of weeks as to what happens. Thanks in Texas.