Rear motor mount

My 95 Galant with 150KM makes a slamming noise when you shift to reverse 8/10 times. Recently the car also vibrates in reverse. The tranny is not slipping. I have changed 2 out of four mounts. I am suspicious of the rear mount now.

1) I put a jack under the car and supported the tranny and the slam and vibration were REDUCED significantly. Is there any other way to know if this is from the mount BEFORE changing the mount.



2) The bolts for the mounts are stuck and lots of stuff on top of them, the fuel filter one of them. If I use a joint to get my extensions on there and then with a long torque put force on it will the joint hold up?



TIA

I guess the question was not very clear. How do I tell whether the reverse slam and vibration is from an engine mount vs the tranny?

Yes that rear mount could be the problem. It is actually called the ‘roll mount’. I am not sure of the location of all the mounts on a Galant so I might be wrong. One way to check the condition of the mounts is to stand to the side of the car while someone else puts the reverse and holding the brake. The top of the engine should move smoothly and less than an inch.

Visually check the integrity of the rubber part of the rear mount. One way to check it is to light up the mount as you lever the top of the engine forward. The best approach is take it out and inspect it. With the mileage on the car it is likely the mount has disintegrated.

Hope that helps. Let us know what you find.