Transmission Mount

[J-ROD]

Has anyone replaced the transmission mounts? If so, do you have pictures or any tips for doing so? Thanks

[myfirstbonnie]

Are you referring to the mount right behind the radiator on the left side?

[J-ROD]

Not sure. I'll take whatever anyone has. Trying to determine if it's something I want to tackle or not.

[00Beast]

Which mounts need replacing? The rear transmission mount normally doesn't fail, and is a PITA to replace.

[J-ROD]

Don't know for sure. When driving at highway speed, unless I'm accelerating, the steering wheel shimmies like the tires are out of balance. But I've had them rotated & balanced multiple times in the last few months & it's made no difference. I will probably replace the easier of the two to begin with.

[00Beast]

I don't think that's an engine mount. Does the engine seem to "shift" under acceleration?

[J-ROD]

Are the terms transmission & motor mount used interchangeably? I had my wife sit in the car & rev the engine, it moves a little, but doesn't seem excessive. How many different mounts are there & where are they located? I have found the front motor mount, below the radiator. I have also found the rear above the cross member. Where are the others? Also the reason that I asked specifically about the transmission mount in the original post, is because that is what a mechanic I had look at it said after he checked it out. I guess in my mind the "transmission mount" would be the one on the cross member in the rear. Thoughts?

[00Beast]

There are 4, 2 engine mounts and 2 trans mounts. The front and rear mounts are trans (the ones you saw), the other two on the sides are engine, bolted to the oil pan. Sounds like yours are fine.

[golfyeti]

Has anyone replaced the transmission mounts? If so, do you have pictures or any tips for doing so? Thanks

Jarod,

The front tranny mount is the common problem. And yes the front mount is interchangeably referred to as the engine or trans mount.

despite the subject line here is what I discovered with my front mount: http://www.pontiacbonnevilleclub.com/fo ... nt#p180353

also searh for posts in this thread for "puck mount" or "bucking" and "surging"

replacing the mount with oem mount or the pucks approach is a pretty easy DYI project

[J-ROD]

There are 4, 2 engine mounts and 2 trans mounts. The front and rear mounts are trans (the ones you saw), the other two on the sides are engine, bolted to the oil pan. Sounds like yours are fine.

When you say "sounds like yours are fine" which ones are you referring to? The front & rear or the sides? Just looking for some clarification, thanks.

[00Beast]

If the engine doesn't move while holding the brake and revving in gear, I don't think that is your issue. I don't think an engine/trans mount will cause a shimmy like that, either.

[2003BlackSapphireSLE]

idk about the whole rear trans mounts dont usually fail thing. i replaced my front mount twice before finally checking the rear mount and finding out it was bad. its a pita alright, but that probably the reason why so many people are going through so many front mounts.

[J-ROD]

I spoke with the mechanic that took a look at my car last Thursday. He said that the issue was a bad front transmission mount, which is right behind the radiator on the driver side of the car. As you can see in the pictures it is indeed cracked and therefore ruined. To remove/replace it.
I took the nuts off of the top and the bottom of the mount. Then removed the three bolts that secure the mounting plate on top of the mount to the engine block. It came right out. Then to install the new one, do everything in reverse. This took about 30 minutes to do. I took it for a test drive afterwords. The car drove smooth with no more shimmy in the steering wheel. Let me know if anyone has any questions.

[1oldman]

00Beast Posted “Which mounts need replacing? The rear transmission mount normally doesn't fail, and is a PITA to replace.”

Both my transmission mounts failed, but I’m not sure when. The driver side has been replaced twice (no, I do not ‘cowboy’ the car). The driver side was replaced around 160K miles. It was replaced a second time when the mount under the floor was replaced (210k miles). The driver side can be done in about 10 minutes. The one under the floor took me about 3 months to replace as I didn’t have a transmission jack or engine hoist. I tried to do it the way the dealer said, but there just ain’t enough room. I had to cut off about half the thickness of the nut on the stud closest to the oil pan. (This is definitely NOT recommended). That mount has three studs on it in a triangle pattern. The other two will fit fine. The rubber on the old mount had completely turned to a very soft goo. The dealer quoted me around $1500 to replace both. Per Edmunds my car is worth $0 ‘cause of the high mileage. I hope someone else can be of more help than I. Good luck.

[00Beast]

My front mount was failed in a similar manner, J-Rod, and it didn't cause a shimmy, and I don't think anyone else has reported a shimmy because of it. I guess you're an anomaly.

Old Man, if you're referring to your 92, it's a completely different setup, so it's apples to peaches.

[J-ROD]

Alrighty. I lied. This mount was definitely bad & needed to be replaced. However it didn't fix the issue. The new transmission mount reduces the impact of the shimmy. However, I can still feel it in the steering wheel. Taking it back to the shop for further diagnosis tomorrow afternoon. Hopefully it's still something that I can fix and not a high cost item.

[J-ROD]

The shop found nothing else obviously wrong. I am taking it back for a rotate & balance (mainly because it's free) to see if this will have any affect on the car. Still looking for suggestions. Not sure if an alignment will help or not. Let me know if you have any thoughts.

[J-ROD]

For anyone that hasn't seen my other post. The shimmy was being caused by a bad CV shaft on the driver side of the car. I replaced it Friday night & all is well now.