What are your part numbers?

You should have.....

3-1116R or 3-1116G (Passenger's)
3-1127R or 3-1127G (Driver's)

The R is red and the G is black.

Mine were a perfectly snug fit in the shells.

 

I had this problem after about 10k miles. I ended up replacing the ES mounts with factory mounts. If I were you and was set on poly mounts I would put the clamshell in a vice and crush the center of it a little. Then try and install the insert again. That should create a snug fit.

 

Ace, those are the correct part numbers. The passenger side wiggles from side to side. If I stick a screw driver inside the bolt hole, I can manipulate the poly insert by moving it side to side.

 

The vice idea sounds like it would work. He had the clam shells welded shut instead of bolting them together.

 

'Goat, you went back to factory rubber because the poly mounts became loose?

 

He has brand new gm mounts but he keeps breaking the trans mount. He thought the motor maybe twisting to much and causing the trans mount to break. The car has a decent cam and makes good torque. It also has a modified trans.

 

I had them out for whatever reason and noticed they were loose. Instead of dealing with having to take them out again in the future, I put original parts back in and haven't had a problem since.
I've never had an issue with my trans mount. When they fail are they separating?

 

The stock gm trans mount breaks all the time. That and optisparks are the worst thing on these cars. ES makes a strong poly trans mount.

I personally like solid motor mounts and solid trans mounts. You will free up 1 to 2 hp with the solid mounts. But its a little rougher ride. especially with a cam.

 

Yeah, the trans mount is a stock replacement from the local auto parts store. It only lasts about a week before the rubber has separated and the trans begins to hit the tunnel. Ill tell him to get a poly trans mount and see if that
will solve the issue.

When you replaced your poly engine mounts with the factory rubber, did you leave the poly trans mount installed? If so, did you notice any ill effects?