I have a 91 T/A with a 305tpi amd a 700R4 tranny I replaced the rubber mount with a steel mount from moroso but the center(and only)bolt that mounts to the crossmember keeps getting ripped out has anyone else had this problem? and how do I fix it I was thinking about drilling two more holes in the crossmember because the mount has 3 holes
if this wont fix it will a polyurethane mount be able to withstand the abvuse of hard launches?

 

A poly mount should hold up to just about anything. I dont know what kind of setup you have but unless it is something major, a poly mount should be fine.

 

I'm not expert on the subject, but I have read that you need to use soild motor mounts with the solid transmission mount. Obviously when you launch the engine twists in it's mounts and if you're not running the solid mounts on the engine and you are on the tranny then you're disrupting the drivetrain geometry. This supposedly puts undo stress on the tranny mount and bellhousing bolts, etc. because you're allowing the engine to twist but not the tranny. This may or may not be your problem.

As far as polyurethane mounts go, they should work just fine. I had my stock rubber mount break on my during a launch at the track and I replaced it with an Energy Suspenion polyurethane mount. These also have metal inside that prevents seperation in case the polyurethane fails. I have had no problems with it at all.

Hope this helped,

Jason

[This message has been edited by 89BlwnRs (edited February 21, 2001).]

 

Thank's i'll try the polyurethane and see how that work's out

 

From all i've heard, solid tranny mounts are a bad idea, even with solid engine mounts. Reason being, the aluminum of the tailshaft is not meant to be subjected to the extreme twisting forces of driveshaft torque without at least some buffering of the load through a poly/rubber mount. At best you'll luck out and rip the mount-xmemeber bolts (as you are.) At worst, your tailshaft will crack leaving you stranded. In between, you could simply rip the mount-tranny bolts out, or simply carck their holes. You woldn't be 'stranded' but you will have an ugly problem to fix.
...ed

 

This is exactly why a solid tranny mount should not be used with standard motor mounts. A torque strap may bandage the problem but I think the bolt may rip out again.

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82 z28 350cid, vortec heads, comp 262h cam, Holley 600cfm carb, 2in twice pipes, MSD ignition, turbo 350 trans, 3.73 posi, manly b&m megashifter