Need some help!
 

I installed the aluminum rear gearbox (just front cover so far. I'm still waiting on the rear) and a derlin main gear (and a crap ton of other aluminum parts) but once I installed the front cover for the gearbox, the differential and the main gear wouldn't make sufficient contact. Has this happened to anybody?

I should probably list the upgrades i have in the car now, because who knows, it may be one of them causing the problem.

It has:

Aluminum rear gearbox front cover
Aluminum rear knuckles
Aluminum rear swing shafts
Aluminum rear suspension plate
Aluminum tie rod cover
Aluminum front lower arms
Derlin main gear
Stage 2 motor
medium stiffness shocks in rear and stock ones in front

Never had a issue like that before, did you install it correctly and place the spur,differential, and spacer in the correct spot? I changed my gearbox front and back all the time , but then agian when I change them it was either GPM or stock front and back never mismatched maybe that can be the issue, sometimes when its the stock and gpm it it doesnt match up properly. You should upgrade to bearing while your at it =) if you havent done so. Hope this helps.

Thanks. Yea, I'm waiting on GPM rear cover and ceramic bearings in the snail mail. Im hoping thats the problem because this is my favorite car

what kind of car is it? I have a collection of xmod body its ridiculous =D

Its my 370Z that I'm converting to a police car. I have a lot too lol :) everytime they were on sale I found myself buying one.