sprog

Chasin a vibration on the mustang. Could the bushing in the tail shaft on the transmisssion be worn enough to cause a vibration?

Gun Jam

absolutely. If you press up and down on the yoke where it enters the tail shaft can you feel it move? If it has noticeable movement you'll need to replace the bushing AND the slipyoke. Dont mess around replacing just the bushing you'll end up chasing your tail.
Replace the bushing, slipyoke and the U joint bearings.

sprog

When I first bought the car I bought a new seal as that seal was leaking and I believe it came with that bushing. I didn't use it but now it seams that I need it if I can find it. Both u joints were replaced. Along with both seals. It is not a constant vibration but goes up and down at a constant speed. I'll try your suggestion. Also I have the dreaded shift/ kick down lever leak and have those to do as well . i'll let you know if it works out.

barstowpo

You might also try reclocking the driveshaft. Unbolt it, rotate it 180 degrees and reinstall it.

sprog

clocking the drive shaft was the first thing I did.

sprog

What about the rear end. Incorrect preload on bearing for input yoke?

sprog

I'm not sure how to set the preload on the rear yoke. had the tail shaft bushing replaced by transmission shop. 10 bucks. Noticed that the rear u joint is really stiff on drive shaft side. Could that be a problem. Previous owner just drove the car didn't do much repair. I did notice that one of the trans mount bolts had been buggered up.so while I have the thing apart iwill replace trans mount. would like to check direshaft balance but ther are no shops around here.
with the rear u joint being tight I wonder if the drive shaft ears are bent?