well i did a hard 2nd gear down shift around a corner and pop goes my pinion shaft.

is this a comin thing to go out on an fc?

i have full 3inch exhaust, wired open 5/6th ports, coldair intake, ACT stage 1 clutch, 18inch rims with 235/40/18 kumos ectsa's.
the car a 167,000miles on and about 50,000 on the motor. the gear oil in the rear was clean and toped off about a month ago and has no leaks.
id just like to know what made this happen.

 

if i had to guess, something had to be wrong like the pinion nut loose. with an n/a it woudl be hard to break the pinion.

 

Very UNCOMMON..