drive shaft question

mhunger · #1 (**permalink**) 05-25-2008, 10:43 AM

Hello all!
I have a strange problem with my 66 sprint GT. I have a groaning/vibrating noise in the driveline when I come off power at highway speeds.

My mechanic pulled the drive shaft and noted that the U joints at either end of the shaft were not perfectly "in phase". That is: the U joint at the one end is slightly misaligned to the other end. Is this normal, or is it someones bad repair job?

thanks for the help.

marc

**Andrew** · #2 (**permalink**) 05-28-2008, 10:55 AM

Sounds like the sliding spline joint was not reassembled properly. The are supposed to be in line.

There are lots of sources of driveline noises and vibrations, which I know have been covered in depth on the BB here if you search. Suspects: U-joints, alignment, balance, straightness, center bearing and rubber carrier, trans output shaft "ball" and matching bushing, diff condition, exhaust condition and mounting, trans mount, engine mounts, ad nauseum.

Andrew

mhunger · #3 (**permalink**) 05-28-2008, 07:17 PM

engine mounts, engine, trans, clutch, T.O. bearing, and diff are all new. U joints are fine, spline is fine. center support is old and is the old style. exhaust is old. I think it could be the drive line, but I don't understand why I only get the noise *between* power and engine braking. I suspect the exhaust could be hitting somewhere. I will let you know what I find out.

**Andrew** · #4 (**permalink**) 05-29-2008, 08:20 AM

On several of my cars over the years, I've gotten a vibration/rumble in the narrow band between power and coasting that I put down to something in the diff (gear mesh run-in and out in the ring and pinion when not under load?), but maybe it's in the spline, as sloppiness when it's not torqued one way or the other?

Andrew