I am thinking of using a polyurethane automatic transmission mount like the prothane/energy suspension ones. I have read that sometimes they can increase the vibrations into the car. Anyone experience that, or any other reason I should not use one? I am using Anchor rubber engine mounts.
I heard of people ripping bell housings apart if the engine can move more than the transmission. As long as your engine mounts are stiffer than the trans mount, additional harshness and vibration are your main concerns.
Okay. I have been dealing with vibration issues for years. I've been considering it might be the drive shaft, which is always a possibility. U-Joints etc. The U-Joints check out fine. I have stock (replaced with NOS before engine went in) engine mounts, but a prothane (I think that was the brand) poly-urethane Trans mount. I wonder if that is what causes the vibration? It is not at all rpm's/speeds, but consistently when decelerating from say 50+ it gets real prominent from like 45 to 40 mph then subsides. I do feel it at highways speeds too though. The whole chassis has a high frequence vibration. All wheels have been balanced. It doesn't seem as severe when accelerating as it does when decelerating although I do still feel it.
Could be, so I have read. The trans cross bar has rubber at the ends which could be degraded and "short out" to the frame. That would transmit vibration from the drive train to the frame via the prothane trans mount.
I put new cross member pads on when the drive train went in but that was 13 years ago. Might vibrate right through them tbh though. Would just be worse if they were really worn out. I think I'll be replacing the tranny mount next spring with good ole rubber..
