diff confirm

[chinna]

in the process of stripping down the drive train on my 1990 m20b25 auto cabby. managed to clean the diff tag enough to get S3,73 8842. does this mean its a lsd? may need to get it rebuilt if it is as after 30 mins motorway driving i would get a horrible groan on right hand bends at normal speed.

[Speedtouch]

Yes, that will be a 3.73:1 LSD.

One way to confirm is to jack the back of the car up and turn a wheel; the other will rotate in the SAME direction if it's a LSD, and the OPPOSITE direction if it's an open diff.

[chinna]

just tested it. its not on the car but spinning one drive shaft turns the other the same way. next question is is there any reputeable diff rebuilders close to coventry. i'm only guessing the groaning/grinding noise is from the diff and not a drive shaft

[Speedtouch]

Have you tried changing the oil?

Gareth on here rebuilds them, but he's in Hastings, Sussex.

[Brianmoooore]

Chances are that if its never been rebuilt, it will have lost most of its 'locking' action by now anyway, but the groaning noise could be down to someone changing the diff. oil at some point for 'ordinary' diff. oil.

[chinna]

pap. oh well i'll go with bmwmad as he's only down the road and get a open diff if theres no reason to have the slipper. it's all off the car anyway. going for a clean and refurb on the underbody including all pipes, bushes and suspension. i've had the old bus for 7+ years and only done general maitenance on her so it's about time i treated it and hope she lasts another 23 years.

[gareth]

If it's only groaning one way, are you sure it's the diff? I'd suspect wheel bearings first.

Does the noise change with throttle loads etc?

[acridsmoke]

Doesn't make the noise in a straight line at all. It only makes the noise after motorway speeds and only on right hand turns

[chinna]

did it before and after i did the bearings and doesnt change with speed.