underneath the transmission there is a bolt i think , i dont know if it is the actual trans mount but mine is cut in half and the trans shakes. im pretty sure there is a rubber boot with it too but im not sure. anyone know the actual name of this part and if its replaceable or not and also where i could find one besides dealer

 

There are three transmission mounts. one on each side on roughly a 45* angle and the center one with the large stud through it. Mine was trashed to so I made a custom one as I didn't feel like trying to find a new one. The rubber has a metal sleeve that is pressed into the cross member, I had to use a hydrolic press to get it out. That leads me to believe it might now be replaceable and you might have to track down a replacement cross member.

 

The transmission is actually held up and in place by the "Y" blocks listed below. The crossmember is more obviously bad because it's bushing actually breaks, while the "Y" blocks rarely break, they just sag, causing the bushing in the crossmember to break out. If you replace the crossmember, but not the blocks, your new crossmember will soon fail. The bushing in the center of the crossmember is not designed to carry any weight.

Take a look at the following:
http://www.mazdatrix.com/g3.htm

Chances are the bushing in the crossmember is gone, so a new crossmember, Y bracket and 2 mounts and you'll be good to go. On the bottom of the Y there is a large washer and nut.

 

Anyone know the consequences of NOT replacing the crossmember mount? Mine is broken out and I just replaced the (2) side or Y rubber mounts. That is lot of money to spend just to get a little less side to side movement of the transmission

 

You get more up and down banging of the transmission. The side to side movement will stop but it will still go up and down with a broken bushing