The owners manual says the differential requires 90 weight oil but all I can find is 80W-90. I called Mazda and they said they always use 80W-90 in the rear end but they include a special additive because it is a Limited Slip Differential.

Any recommendations? Is 80W-90 safe to use? Do you use an additive? If so, what kind?

 

80W-90 is fine the More important requirment is GL-4 or GL-5 compatible. You can use any GM additive in the LSD. I use it in my KAAZ.

 

I'm sure that 80w-90 will work fine... that's what I put in mine and it is OK

The additive is for clutch-type (slipping disks) LSDs like is found in a 1987 Turbo II. The third gen uses a Torsen type LSD which uses little worm gears inside there. There is no friction surface, so there is no need for an additive.

Brian

 

I agree about the clutch type comment but not with the NO friction surfaces. Those worm gears create a hell of alot of friction while turning against eachother. But good pointing that clutch type are the ones that "need" the additive.

 

True, but the power transfer is not dependent upon the friction, but upon the incline plane theory of screws. Whereas with the clutch type, or any clutch for that matter, depends upon friction to transfer the power.

 

Yep! Just didn't want any "bad" thoughts that gears don't create friction on eachother. Friction is a funny thing...It can work for you or kick you in your *****!!! Again, I wasn't flaming or saying wargasm is totally incorrect,It could just be taken the wrong way by some. Aloha, Dave