I just received a used OEM diff and case from an S2ki member. It came off a car with about 15,000 miles. The seller was very straight-forward and I have no reason to doubt him. But something doesn't feel right when rotating the axle flanges.

When playing with the diff loose on the floor, I noticed that when turning the axle flanges by hand there seems to be some 'catching' or 'popping' when turning them in opposite directions. By that I mean that they'll rotate freely for a few degrees, then they get tight enough that it takes a fair amount of force to continue the rotation. You can pop the flanges free using only hand pressure on the flanges, but it's more than I expected. There's no noise or grinding feeling throughout this sticking and slipping.

Note that it is completely smooth when turning both flanges in the same direction (as if the car were rolling) or turning the input flange. This points to the torsen diff as the sole contributing factor in this feeling.

Should this be cause for concern? I've played with a Quaife LSDs in a couple cars and a torsen front diff in an '05 STi without feeling this, but in both those cases I was turning the tires on a complete vehicle so there was a lot more leverage.

Note that this will be used for A-Stock autocross competition where only OEM diffs are allowed, so don't bother mentioning aftermarket diffs.

 

Was it shipped with oil?

 

Good question the LSD will not operate smoothly without lubrication. Open up the fill bolt and set the rear level on the floor like it would be mounted in the car. Check to see if fluid runs out of the fill plug, if not add fluid to the rear until it does.

 

LSD unit is sticky.

Mine has been like that for 50k miles, and I've seen many s2k's like it. Mine sticks so much there is no way you could turn the dif flanges in opposite directions by hand if the dif was out of the car. It has no effect on the operation of the dif.

Run it

 

Billman250 Posted on Nov 11 2007, 03:09 PM
[QUOTE]Run it

 

Check on this

then do this

 

Duh - Didn't think that oil would affect the torsen!

I was planning to fill it with LE before using it.

 

Gears on gears, yep oil will have an influence. Torsen even advises using heavier weight oil for less differentiation.

 

INTJ Posted on Nov 11 2007, 09:07 PM
No, they don't.
Link please.

The S2000 has the T-2 (or Type 2 or Type B).
According to this website it is ATF compatible.
Not recommended for the S2000 though!
http://www.torsen.com/products/T-2.htm
At the home page of this site they recommend a GL-4 or GL-5 oil.
At the specific T-2 site (linked to above) the ATF is mentioned.
The bias is set with the gears.
Oil doesn't change it.

The final drive of the S2000 is the deciding factor IMO.
SAE 90 GL-5.