I was given this diff when I bought my two door shell off . I was told it was an uprated unit!!!! I know its difficult one to answer but any info would be good.

Numbers on the casing are (85, KN51).

http://i228.photobucket.com/albums/e...tyrd/diff1.jpg
http://i228.photobucket.com/albums/e...tyrd/diff2.jpg

Thanks Matt.

 

The casing could be the carrier for many different diffs.
From the photo I cannot tell but look into the LSD unit to see if there are a number of plates stacked together.
Typex a tooth on the crown wheel and count the teeth. Then repeat the exercise with the pinion to determine the diff ratio.

 

Looks like my Sti viscous to me.

 

Ok thanks, I'll strip the diff down and count the teeth. I bought the type r shell off John Stokes about 18 months ago but cant find his e-mail address anywhere. Basically ive been offered a sti 6 gearbox with the DCCD and wondered if the diff would be compatable.

Thanks Matt.

 

Since you have the cover off do as Harvey suggests and tippex a tooth, then count how many times you have to spin the prop flange to get one full revolution of the crown wheel.

As you probably know, it needs to be a 3.9 rear to be compatible with a DCCD 6 speed

 

Just stripped the diff down.
Large gear has 39 teeth.
http://i228.photobucket.com/albums/e...rdiff00239.jpg

Small gear has 11 teeth.
http://i228.photobucket.com/albums/e...rdiff00311.jpg

Thanks Matt.

 

3.54 diff then, but can't place the type or the car its comes from

Mark A

 

The 3.545 rear diff is fitted to uk cars with a 1.1:1 drop gear/centre viscuous diff.

 

Ok guys, thanks for your help.
Guess the search for a compatable diff continues.

 

Just to let you know thats not a viscous lsd, but actually a mechanical lsd, clutch type I'm pretty sure.

 

[From the photo I cannot tell but look into the LSD unit to see if there are a number of plates stacked together.]

Remember that the centre viscuos diff is the section bolted on to the rear of your gearbox.

 

Might help, this sis a visous rear diff from my Sti V3:

 

Check my thread for Diff pictures

Mark A