Does Tochigi Fuji Super LSD need a friction modifier?
 

Hi!

I ran into a small hickup while preparing a service for my friend, he has a 2003 sport with 6 speed and a locking differential. I personally have a Torsen so I have just always put a mix of lightweight shockproof and MT-90 into the differential without ever really thinking more about it.

I realized that he might have the Tochigi Fuji Super LSD since the car is a 2003 so I was wondering if that particular LSD needs a friction modifier to work properly or not. I understood that it is not like a traditional clutch based LSD, but instead uses cones of some sort.

Problem is quite simple, can I just tell him to put shockproof and MT90 without caring if it is a Torsen or TFS?

I wouldn't put shockproof in it. Wet Clutches are very picky about the oil they require. I would put exactly what it asks for in the manual and nothing else. Idk what the spec is, though.

For reference, I know of situations where the wrong oil caused the adhesive holding the friction material to be dissolved in a wet clutch system.

Also interested in what the Fuji calls for - anyone know?

Redline MT-90 will work just fine :)

I would use whatever is called for in the manual as well.

We did this in my MazdaSpeed 3 years ago, used whatever "super bad ass $$$$$$ fluid" that was supposed to be awesome, and it didn't have the right stuff. The car was back in the shop 400-500 miles later to put in the proper Ford stuff to get rid of the weird chatter/lockup issues it was having.

Hmm, i guess it is the best option then to follow the manual and put GL5 whatever that is. Thanks for answers. I am still curious however if this cone thing is actually sensitive to wrong oil or not.