E28 M5 motor mount part #?

[Jason89i]

Both of my green mounts have torn at the lower stud and compressed enough that I've had to add an additional 1/4" of spacing for the oil pan to clear the rack. This is after about 30k daily-driven miles, about 7 autocrosses..

the motor mounts should fit freely in the holes. both mating surfaces should sit square. i have noticed A LOT of swaps where the motor mounts dont sit square on the arm or the subframe.....the owners just tighten the bolt enough to force it into square. (i too did this my first couple of times.) you will see the green paint crack as the rubber gets a horizontal force and the stud gets a moment arm along the long axis. you will see early motor mount failure as the moment force compresses the rubber on one side, streatches it on the other, tears the rubber away from the metal housing and ultimately horizontal force sheers the bolt.

i have noticed that some cars (specifically my 3/87 m3, and an86es) needed to have the subframe mounting holes spread apart by about 1/8" total. (not noticed on the 7/89m3, 91is, 89i, 90i or the 88is.) and since everyone should be reinforcing the front subframe, its an easy job.

cheers, jason

[dougsic]

the motor mounts should fit freely in the holes. both mating surfaces should sit square. i have noticed A LOT of swaps where the motor mounts dont sit square on the arm or the subframe.....the owners just tighten the bolt enough to force it into square. (i too did this my first couple of times.) you will see the green paint crack as the rubber gets a horizontal force and the stud gets a moment arm along the long axis. you will see early motor mount failure as the moment force compresses the rubber on one side, streatches it on the other, tears the rubber away from the metal housing and ultimately horizontal force sheers the bolt.

i have noticed that some cars (specifically my 3/87 m3, and an86es) needed to have the subframe mounting holes spread apart by about 1/8" total. (not noticed on the 7/89m3, 91is, 89i, 90i or the 88is.) and since everyone should be reinforcing the front subframe, its an easy job.

cheers, jason

Great observation! Thanks.

[Brew]

Got the new mounts in about a week and a half ago. Turns out the "right-side" e28 m5 mount is the hexagonal type. They look just like the green ones but are painted gray...
Anyways, if these are the same mounts as the green e28 mounts I had, my old mounts were compressed by about 1/4" after 30k miles or so. No noticeable noise or vibration increase with the new mounts, but I don't notice much with all the diff noise coming through the poly subframe mounts and rollbar.

[Mohammed_A]

which are the e21 tranny mounts, any pics of the e21 tranny mounts?