Quick backstory: Been experiencing a mild vibration in my 85 TA since I got it running well enough to get it up to highway speeds. Started around 50-55 and continued through as fast as I was able to push it (about 70mph). Vibration seemed steady, did not worsen at higher speeds. Pushing in the clutch to disconnect engine and trans did not lessen the vibration, maybe made it a little bit stronger. I had replaced the tires back in November on a Black Friday deal, but took the car in yesterday to have the wheels and tires rebalanced. Then I started reading here... No answer why I didn't do that first as I have been a steady visitor since buying this car back in October. Balancing the wheels did not take the vibration away, but after reading all the posts on the poly trans mount transmitting vibrations, I knew that was a good place to start looking, as a PO had installed a poly mount.

Picked up a rubber trans mount from OReilly's for $17 (Power Torque B2811). Prices seem to have gone up in the past few years - tariffs maybe?! Part is made in China, is not a solid rubber piece but looked solid and I decided to give it a go.

Purchased at OReilly's for $17, including tax

Before removing anything, I wanted to check the pinion and trans angles to see if there was any change. However, I just realized as typing this out that I probably did not measure it correctly. I attached my angle finder to a bracket off the trans and the torque arm, but probably need to stick it to the driveshaft?

Here are height measurements of the two pieces and a profile picture of the rubber mount:

Rubber mount = 52.5mm

Poly mount = 45.9mm

Cleaning the trans crossmember and hardware took more time than removing and reinstalling the trans mounts. I did find that the mounting bolt was just a hair off center. Even with the adjustment slots in the crossmember, I had to give it a nudge over to get one side of bolts in.

However, once reinstalling and torquing to spec, I took the car out for a spin. Vibration is GONE. That was cause for a celebration, and it was right at happy hour, so...

Car has all new front suspension components, cannot speak to the age or condition yet of the motor mounts or rear suspension. Rear will be getting replaced when I convert to fuel injection, and I wish I would have replaced the motor mounts when I had the engine jacked up to change the oil pan gasket. Next time...