cant figure out what differential i have.......

[Dustin792]

hey everyone,

I recently bought a 1990 240sx , if i can remember the person i bought it from told me there was an infiniti differential , im assuming he ment the j30 lsd . im not familiar with these cars and was wondering if theres a way i can identify which differential i have. If u look at it from the back of the vehicle theres a drain plug on the back and near the top left side theres a fill hole , also theres what looks to be heatsinks/fins on the differential for cooling im assuming. anyhelp would be greatly appreciated. if u have any questions i can take another look at the diff whenever thanks alot
Modified by Dustin792 at 8:01 PM 2/21/2009

[manzo240]

my car (91) has the stock open diff and it looks just like what u described, on the s14 there is a sticker on the side of the diff. also if u have any buddies with stock s13 diffs compare the bolt patterns on the axles cause there different than the j30s. the only other thing i can think of is the wheel spin test- car off the groung: transmission in nuetral both wheels should spin freely the same direction- transmission in gear wheel is harder to turn other wheel spins opposite direction hope this helps

[Dustin792]

so u mean if i spin the left rear wheel and the right rear wheel spins with it then its a lsd? and if the wheels just spin seperately then its a stock diff? thanks for the help

[Dustin792]

so u mean if i spin the left rear wheel and the right rear wheel spins with it then its a lsd? and if the wheels just spin seperately then its a stock diff? thanks for the help

[ashoe]

Yeah, that is all there is to it. The j30 gets put into the stock differential housing so there isn't any way to tell from the outside if it's different. you have to open it up to know for sure. Another way to do it is find an empty parking lot rev the engine up, dump the clutch. If you get two black lines you have an lsd. one black line, an unfortunately open diff. have fun.