rear sub frame bushing restoration

How to restore rear sub-frame bushings with polyurethane for approximately $30. Using 80A durometer 2 part polyurethane casting compound from Mcmaster Carr (mcmaster.com), part number 8644K11 for $26.66.

Cut the stock rubber "bumpers" off the bushings. Then drilled 3 1/4" holes (to make 1 wide hole) all the way through the rubber bonded to the outer case (not the rubber connecting the case to the center piece) to have a rough area for the poly to bond better to, to get rid of more of the soft rubber, and to have 2 more through cannels for the poly to flow through to connect the top "bushing" to the bottom "bushing" better.

I made my "molds" out of cardboard sealed in duct tape and things turned out very well. Make sure you don't spring a leak. Mine started to set up just in time to stop the leaking before I ran out of urethane.

It made a big difference in the tightness of the whole car, and really cut down on rear body roll. There is slightly more vibration and road noise, but well worth the improvement in handling. Before, I used to get rear wheel hop and the subframe would slap the bottom of the car. This really cut down on the wheel hop and the subframe stays put.

Source: http://www.cardomain.com/ride/785257/1981-bmw-3-series/page-7

Author: Member ID: jrcook320

Location: Van Wert, OH  

NOTICE:  This is a cut-n-paste of a brief essay i found at cardomain.com and thought that the information was so important to me i wanted to store it here so that i would have it at my disposal and i also felt that the information in the essay is so valuable to the true hobbyist, and therefore worth passing along to the Legion.