Lsd recognition

[gomango]

Could someone tell me if I have a Slipper on board(1990 325i SE),The tag says 3:73 and the numbers come up 9902,I have the Car up on Stands and both hubs are spinning round together so to speak,Thanks in advance.

[Speedtouch]

If you turn one wheel and the other turns in the same direction then it's an LSD. If they turn in opposing directions, it's an open diff.

LSDs normally have an S on the tag prior to the ratio, e.g. S3,73.

[leeparkes]

Do a monumental wheelspin!
if you have 2 lines you have a slipper!
also do the checks maurice has pointed out.

[gomango]

Thanks

[mrLEE30]

If you turn one wheel and the other turns in the same direction then it's an LSD.

or its welded...

but as he says it should read S3.75 9902 if its a LSD, just 3.75 9902 indicates a 3.75:1 ratio open diff