I have been worried for quite some time about vibrations in my drivetrain. When I first got the car on the road last fall I was worried about the flywheel balance - even with the car standing still and in neutral, revving up the motor made the whole assembly wobble. After replacing the clutch and having the flywheel balanced, this test produced very little shaking. However, the car still shook like crazy while driving, especially at certain motor speeds (seemed to be between 3000 and 3500 rpms). I mean, I thought the car was going to shake completely apart (not to mention reduce my fillings to dust!).
The other problem I've been having is that the clutch stops working from time to time, especially when it is very cold out. Not good. So, this weekend I replaced the clutch hydraulic assembly and reinstalled the original (rubber) transmission mounts. No pictures, but here's how it went:
To access the top of the transmission I had to remove the accessory battery, vacuum pump, and the "high voltage" electrical box (the box that houses all my shunts for measuring current). Then I removed the right-hand (driver's side) tray from the engine compartment. Then I disconnected the slave cylinder from the transmission and the clutch pedal from the master cylinder pusher rod. In order to pop the assembly off the firewall, I had to disconnect the brake master cylinder from the booster and nudge it away from the wheel well so there was room for the clutch master cylinder to be pulled straight back from the firewall. Installation was opposite of removal, except for the part where I accidentally popped the top of the reservoir and poured brake fluid all over the splashguard.
Replacing the transmission mounts was pretty easy, though I ended up loosening the left side tray in case the motor came in contact with it when I raised the transmission. Removed the driver's side front wheel, fender liner, and splashguards. Removed the solid torque rod from the top of the transmission and chassis frame, removed the nut which attaches the lower transmission mount to the frame and the bolts which attach the mount to the side of the transmission. Using a floor pump jack, I gently raised the transmission high enough to clear the stud which protrudes through the frame and removed the solid mount. Installation was the reverse of removal. Lowered the transmission assembly back onto the frame and installed the nut on the stud sticking down into the frame. Next I installed the torque rod on the top of the transmission and into the chassis frame. I had to push back slightly on the transmission to get the bolt to go into the frame (which means that the hard mount on the motor side is probably a tad off center).
After reinstalling the equipment trays and all the components I took my first ride with the rubber mounts. All I can say is the difference couldn't be greater. It was so quiet I felt like I was in a cushy Cadillac. And the clutch was working like a dream. Oh, the EV grin was back with a vengeance! I couldn't believe I waited so long to put those rubber mounts in. The car is a joy to drive now! There are still a few motor speeds where you can feel vibrations, which I think is related to the fact that the motor is still hard-mounted, but I no longer feel as though the car is about to disintegrate. I'm back in business!