STi diff bushings and carbon driveshaft

[gpvecchi]

Lowering our car doesn't change pinion angle

[Matt93SE]

Originally Posted by churchx

My line of thoughts goes that diff riser bushings are not there with goal to just change said pinion angle for no reason. They are there "to fix"/revert pinion angle closer to stock on overlowered car (also reducing CV joint angles). That in turn probably means, that if car is not dropped very low, then their installment nets those mentioned problems instead of doing something good, and thus should not be used.

Changing the pinion angle is a nasty side effect of using the diff riser bushings. The people that made those bushings attempted to fix the CV problem by raising the diff in the subframe, but moving the diff causes another, more serious problem with the bad angles and driveline vibrations.

it's possible that the riser bushings could be welded into the subframe into a better spot to resolve that issue, but the instruction manual says nothing about it. It simply says to bolt the diff in place and weld. And of course with solid bushings, there's not much choice where everything lands. so I bolted in the diff in place and welded, just like the instructions. Well now that's pretty permanent, isn't it?! fortunately I was able to stick a die grinder in the holes for the rear mount and slot the holes to drop the rear of the diff and return the angles to their happy place. I then welded fat washers over the slots to hold it all still. Not the ideal thing at all, but I made the best of what I had vs. replacing the subframe.