I was wondering the same.I'm confused as to the upside of taking the 330 ZHP diff out of the car and putting in the diff from a 325.
i've done this a few times on diffs. not sure which one you have, but Craftsman socket fit. not sure how many points my 30mm socket is but it's thin enough to fit. now if Craftsman made them thicker later i do not know.I'm swapping my stock ZHP diff with a 3.46 diff from a 325i. I need to swap the input flanges but neither my craftsman nor gearwrench 30mm socket will fit around the nut on the pinion shaft. Any suggestions? How has anyone else here done it?
because the 330 ZHP has a 3.07 ratio diff for it's manual 6 speed while a 3.46 diff will be a much better performance ratio mated to a overdriven six speed. Almost all magazines who tested the 330ZHP published how they wished BMW would have fitted the 3.38 or 3.46 for the ratio instead of 3.07. stock was 2.93Taking that nut off will put you in the position where you need to check and adjust the gear mesh between the ring and the pinion. Even if you don't replace the pinion gear, you will be relieving the thrust pressure on the bearings, this means that the gears will be affected.
I'm confused as to the upside of taking the 330 ZHP diff out of the car and putting in the diff from a 325.