[Guest]

My original rubber trans mount was so bad the auto shift lever would jump during shifting, and the trans tail shaft could be seen bouncing up and down during idle. Since I was going to replace the mount, I went with a polyurethane type.
I didn't change the front motor mounts. I'm getting a noticeable vibration now, especially during acceleration. Is more vibration to be expected with the poly mount? The only other thing I changed at the same time, was the crankshaft pulley. I am installing the Vintage Air A/C system and the system comes with a heavier crank pulley. It appears to be running fairly true, though not perfectly so.

 

[68restomod]

Time to look at u-joints. Should be no play felt. Make sure parking brake on and put the car in Neutral to take the tension off the driveline.

Good luck!

 

[Guest]

I haven't checked the u-joints in a while, will do. I am, however, getting the vibration when I rev it up also in park or neutral.

 

[70Coupe]

I'd take a look at the motor mounts.

 

[Dinosawnj]

Since rubber has more give (insulation property) than poly, you will feel more vibrations. However, it doesn't mean that the source of the vibration can't be isolated and reduced. What's the condition of your damper?.

 

[dcudmore]

I also go with the u-joint. Took my 65 for first test run last night, also had a vibration, new u-joints as well..But, I guess one of the internal locks did not hold together and the u-joint went..Managed to keep slight pressure on it and drove the 2 miles back to the shop where it fell right off..New ones should be intomorrow..
Don

 

[Guest]

Thanks for the replies. The dampner is new. I just finished re-installing that Vintage Air crank pulley, it was just a little bit off (it's also a cast steel job, almost weighs more than a brake drum). Gonna check the u-joints and motor mounts now.

 

[Dinosawnj]

If the pully weights that much, I wouldn't use it (too much weight on the crank nose). A good stamped steel pulley (OEM or from someone like March) would be preferable. Just my $0.02. Bob.