The ES poly tranny mount is 1/4" higher (with preload plate) than the stock one. So the tranny sits 1/4" higher. How much do you think this changes the pinion angle? and if so, negatively?

-- Joe

 

Yes it will change the pinion angle. Whether it does negatively or not depends on what your pinion angle was before.

 

you dont NEED the shim plate... so if theres a prob, you can try it with and without....

 

I got really bad vibrations with the shim in - took it out and now just have a slight one at 2200 rpms

 

i used washers to drop the crossmember down a bit, that way i could still use the preload plate, and my tranny was in the right spot.

 

Maybe not on a 700R4.. on a T5, the backing area is hollow, so the poly material doesnt compress correctly. Thats why they call it a preload plate. Its most neccesary.

-- Joe

 

It doesn't change the pinion angle itself, directly; but it does change the drive shaft angle where it meets the pinion, especially if you use the plate. The end result is the same: the pinion is pointed downward farther compared to the drive shaft, because the drive shaft points more upward as it extends away from teh yoke toward the trans.

The only way to restore the pinion angle to the stock range is to have an adjustable torque arm.

I'm not at all sure about this "preload" business having anything whatsoever to do with compressing the mount material. It wouldn't surprise me if what the real intent is, is to increase the negative drive shaft to pinion angle, such that when the rear end torques up, if it was moving too far (all the way through zero to positive), the correct angle under load is established (which would be near zero). But, I don't know any of that for sure, I'm just guessing. Maybe somebody from ES could tell us more.

I can tell you though, the plate made no difference whatsoever on my T-5 installation. Not to hookup, or vibes, or anything else. I ended up not using it.