I got off of work at 3am last night and decided to do some dougnuts in the parking lot (no one around, tough day). My lsd didnt lock up at all. I havent changed the fluid yet so im going to do that and see if there is alot of metal residue in it. The problem is I havent changed it yet so I dont know what im doing. I am guessing that the bottom bolt is to drain it and the top one is to fill it. am I right? any suggestions on what would cause my lsd to just stop working. It hasn't made any noises...

 

yeah bottom bolt drains and top bolt fills..fill it up to where its coming out of the top bolt and your set...now as far as the lsd quit working idk about that...i just got my car so im still learning but helping ppl if they need it....

 

please note that you have to use a lsd additive to the gear oil. i believe that s4 clutch type lsds have been known to go bad. also i think my lsd had a tag on the fill/check plug indicating it was an lsd. i could be wrong as its been a while since i looked at it.

 

You have an open rear.

 

you are wrong...88 GTU = lsd. straight from the FAQs:

Did my 2nd Gen RX-7 come with a Limited Slip Differential?
Only the following USA model 2nd gen RX-7s had a LSD from the factory:
86-88 GXL
87-91 T2
88 GTU
89-90 GTUs (however not the 89-90 GTU)
It is also rumored that a few rare 91 coupes with both the A (upgraded the interior trim, added a power sunroof, tilt steering wheel, cruise control, and 4 piston front disc brakes and vented single piston rear brakes) and the B package (leather seating, a CD player, and rear cargo cover) came with a LSD, but you should note that Mazda denies that any FC other than the T2 came with a LSD in 91). You can also tell by looking at the differential as there will be a LSD tag on S4 cars with a LSD.

I know it had lsd because the wheels spin the same way when jacked up in neutral and opposite ways when in gear. I used to be able to do doughnuts and when I burned out both wheels would spin.

 

i thought that the gtu was the s5 replacement name for the gxl? anyways it is possible that someone swapped out your lsd for an open diff.

 

It could be that the clutches are gone if it locked up before.
If you are changing the oil, make sure you take the top bolt out first. It sucks to have no oil from opening the bottom first when you cant refill it because the top hole is seized shut.

 

Hahaha, that would suck!!! I read that that happened to a guy doing a transmission flush... also, isnt there diff rear end oil for LSD and Open diff?

 

nice tip ima be sure and do that when im ready to change the fluid in my rear end

 

Changing the fluid fixed the problem.

 

now i know what i have to do when mine quits workig and what weight did you put in it?......