High speed Vibration - tailshaft bushing question

[charger360]

I have the same problem with my 74 not really bad but not a smooth as I would like. I have tried a different drive shaft new bushing, tires, wheels, alignment too. next up drive shaft angle, I am going to use some wedge shims to see if it helps, I am about 2 degrees down right now but under load it may be getting to zero or angled up.

 

[Bill Monk]

UPDATE:
Took the drive shaft in to be re-balanced. U-joints are good. Spline is good. Balance was off a little bit. They moved the front weight and the shop said it was running smooth on the machine. Put it on the car--it's running smoother below 60 (I thought it was good before), but the 60+ mph vibration is still there.

I don't want to spend time or money replacing the tailshaft bushing if that's not a likely culprit. Maybe I'll go back to wheels, tires, and brakes. Brakes are new, but I don't think the drums are. No vibration when stopping hard. Tires are new and have been balanced twice. Maybe a wheel is a little bit out of round. Front end has been completely rebuilt.

Just out of curiousity, were the tires road force balanced? As far as I'm concerned, it's the only way to truely balance a tire/wheel. It will also show any problems with out of round issues

 

[70Bronco]

Just out of curiousity, were the tires road force balanced? As far as I'm concerned, it's the only way to truely balance a tire/wheel. It will also show any problems with out of round issues

I don't know if they they were road-force balanced. I know it has its benefits, but I've seen significant tire issues visible on a spin balancer too, so who knows?

 

[70Bronco]

I have the same problem with my 74 not really bad but not a smooth as I would like. I have tried a different drive shaft new bushing, tires, wheels, alignment too. next up drive shaft angle, I am going to use some wedge shims to see if it helps, I am about 2 degrees down right now but under load it may be getting to zero or angled up.

Good luck, man! If I learn anything that fixes mine, I'll post an update.

 

[Bill Monk]

Geez, I hate that you are dealing with all this. Vibrations can be rough to figure out but you'll get it, please let us know what the issue was once you pin it down. Threads like this can be a huge help to somebody having similar problems. Good luck bro!

 

[resq302]

Where can I buy this tailshaft bushing removal / installation tool ?

I'm now getting a vibration in my 69 GTX convertible at lower speeds around 35-50 mph with the foot off the gas or partial throttle. I have what I think is considerable play in the slip yoke and the U joints are new. I tried rotating the tires front to back and no significant change. I just put new radial tires on and I never noticed this issue with the bias ply tires but I also never noticed the play in the tail shaft before. Any help as to where I can get this tool ?