I had an interesting result on my 1982 300D after changing the mount at the rear of the transmission. It was in pretty bad shape, going pretty soft - but not allowing metal contact.

With the new mount nicely in place, it seems to be transmitting a throbbing or strumming vibration up into the car that I didn't notice as much before. It's most apparent when starting off from a stop as a vibration and then at highway speed it tends to throb in and out about once a second. Not very noticable at all at Interstate speeds.

The flex disks looked good. I have new ones available and I also have a new center bearing and mount on-hand that I can put in. The existing flex disks looked good enough not to bother replacing.

Any insight into how often the rear transmission bearing goes bad? The other possibility, considering where the vibration seems to be coming from is the center bearing or perhaps flex disks. Changing out the mount either allowed more vibration to pass that was there all along, or has lifted up the transmission a bit and changed the load on the center bearing.

I suppose the next logical step would be to put in the flex disks and center bearing/mount that I have on hand. Anyone have any experience with the rear transmission bearing going bad? Don't suppose its replaceable from the back of the mounted transmission, is it?

Ken300D