I had posted a few days ago about the wickid vibration I had after my clutch change. We were on the brink of putting a new flywheel in since that seemed like the only possibility. The vibration was there regardless of gear, stopped or moving, clutch in or out, and it got waors as RPM increased. As a last ditch effort before the flywheel change I decided to swap the stock tranny mount back in. I had put in an Energy Suspension mount. Hard as it was to believe, the tranny mount was the culprit. I don't know how, but the car now is running as smooth as it did when it was new. Maybe if used in conjunction with urethane motor mounts the vibration wouldn't be bad but I don't know. So after my experience I would recommend not using a urethane tranny mount unless you want your fillings rattled loose.