The rear mount for my differential has started to fail, with most of the rubber detached from the metal housing. While I could order a new one from Toyota, I decided to try a cheap trick used in the hotrod world to stiffen motor mounts -- filling the mount with urethane.
I used 3M Window Weld, available at many auto parts stores in the US, to fill in the voids of the mount. The black urethane material has a shore hardness rating of 50-60a, with is relatively firm but still flexible. Some of the high-horsepower guys use a filler that's in the 80-90 shore range, which provides a very stiff mount that can transmit a lot of vibration and torque into the body of the car.
Here's a DIY article on someone using Window Weld to fill a motor mount:
http://importnut.net/motormount.htm
Here's pics of my mount and the finished product:
![Image]()
It's hard to tell in this picture, but the only part of the mount attached to the housing are the two big tabs. And the tab on the left has begun to tear away from the mount.
![Image]()
The finished product curing on a shelf. It takes 24-48 hours to fully cure. I started filling only the voids around the rubber, but ended just filling the entire thing. I left the existing rubber in place, completely encased in the window weld material. With the mount attached to the differential, it's possible to wiggle it back and forth just a bit -- I would say it's firm but not solid.
After a couple days of driving I’ve felt no hint of vibration and no odd clunks or other sounds from the rear. The mount seems to be working as it should.
Only time will tell if this was a good idea. The Window Weld cost me around $15, so I'm not risking too much. However, I would say it's a workable idea if you're on a tight budget.
I used 3M Window Weld, available at many auto parts stores in the US, to fill in the voids of the mount. The black urethane material has a shore hardness rating of 50-60a, with is relatively firm but still flexible. Some of the high-horsepower guys use a filler that's in the 80-90 shore range, which provides a very stiff mount that can transmit a lot of vibration and torque into the body of the car.
Here's a DIY article on someone using Window Weld to fill a motor mount:
http://importnut.net/motormount.htm
Here's pics of my mount and the finished product:
It's hard to tell in this picture, but the only part of the mount attached to the housing are the two big tabs. And the tab on the left has begun to tear away from the mount.
The finished product curing on a shelf. It takes 24-48 hours to fully cure. I started filling only the voids around the rubber, but ended just filling the entire thing. I left the existing rubber in place, completely encased in the window weld material. With the mount attached to the differential, it's possible to wiggle it back and forth just a bit -- I would say it's firm but not solid.
After a couple days of driving I’ve felt no hint of vibration and no odd clunks or other sounds from the rear. The mount seems to be working as it should.
Only time will tell if this was a good idea. The Window Weld cost me around $15, so I'm not risking too much. However, I would say it's a workable idea if you're on a tight budget.
