Rear Differential

[mshaw067]

ok now i have a question, my 87 had a posi track rear end. no lsd now when i am on the highway doing about 100 to 120 sounds like it is wining....... could that be the rear diff i dont think the rear diff lub has ever been changed. how do i change it and what should i use for the posie track rear end. also can i up grade the rear gear for a higher top speed. I think my car has the 4.10 rear end, can i put a 373 or something like that would that be worth it..?????

 

[RazoE]

If your car's a turbo, it's a 3.91, if it's NA it's a 4.3..

You can put in any differential from the US

87/88 Turbo = 3.91 LSD (posi)
89-92 Turbo = 3.73 LSD
86.5-92 NA = 4.30 LSD/Open

I have a TT-R (JDM) differential in my 89 and that's a 4.10 Torsen differential, but you have to swap pumpkins if you want to use your stock hardware, otherwise you need all the rest of the associated differential items if you want to swap the TT-R diff in without swapping pumpkins...

 

[te72]

There was also a 4.30 LSD in the sport package equipped (TEMS, headlight squirters, etc) NA's... putting a 3.73 in it will return both higher potential top speed and mileage, but at the risk and sacrifice of acceleration.

To answer your question of what fluid to use and how to change it, it's not very hard at all, however I'll offer this tip: PULL YOUR FILL PLUG OUT FIRST. You really don't want to drain all the fluid only to find out that the fill bolt it seized shut.

The fluid should be 75w90 or 80w90, I forget which. Either should be acceptable, but check your manual and do your homework.

 

[mshaw067]

ok thank you. In my mk3 n/a I have the TEMS head light squarters and posi rear end. no targa or moon roof though.

 

[hvyman]

Have to look on the door jam or diff cover or jack up the rear wheels and spin them to find out for sure.

 

[mshaw067]

for the posi. I have loked under the hod at the axle code it is posi. I drive race the car and the ass hooks very well. thank you though.