Different Material for Motor & Tranny Mounts

[vinsanity]

I installed a universal crossmember tranny mount under my AX-15 so I can drop my skid plate without supporting the drivetrain. It is hard mounted to the transmission & t-case and then has poly bushings at the frame. I feel like I read long ago that it's not a good idea to mix rubber and poly. Either motor & tranny need to be both rubber or both poly. I can't find that thread anymore though.

Is this true? If so, how big a deal is it? I've read it's pretty unpleasant to have poly engine mounts, and I couldn't find the right size rubber bushings for the crossmember. That said, if I'm risking cracking my transmission housing... I'll do what needs to be done.

 

[Goatman]

Poly dosen't like to move. Rubber does. Some claim the movement at the rubber engine mounts gets concentrated at the poly bush due to it NOT moving and can cause the trans to crack or split from the stress. Others claim not. All I know is don't use poly bushings unless you want to feel all that vibration up into the body. Stick with rubber. Far better for this (really any bushing location) use.