SHouldn't both rear wheels spin when an LSD is installed...?

[shaytanabyad]

Guys,

Am I missing something (like a working LSD)?

[mottati]

stock is only 25% lock up, so not necessarily all of the time. but looking at the video, i'd expect you to get some motivation from the right rear. Probably worn out.

[PorscheH6]

fried clutch pack

[konarider98]

Have you had both rear wheels off the ground and rotated one wheel with the e brake off in neutral?

If both wheels rotate the same direction you have a limited slip differential.

If the wheels rotate opposite of one another you have a open differential.

If you don't know what I am talking about ask whoever installed the "3.15"

[shaytanabyad]

Sorry. I should have given some backstory... My brother and I installed the diff and it had the coveted "S" on it...


The donor car never ran so it wasn't pre-tested. Would a "fried clutch pack" essentially turn an LSD into an open diff? Any way to check w/out taking everything out?

[Leonator134]

Yes, yes they should.

[demetk]

Would a "fried clutch pack" essentially turn an LSD into an open diff? Any way to check w/out tacking everything out?

Have someone slowly turn a wheel in one direction. If you can freely turn the other wheel in the other direction without any resistance the clutch is gone. On a bad diff, I could easily turn the output flanges in opposite directions by hand. On a good diff, I could not. There are write-ups on changing the clutches. It doesn't look too complicated.

[Hofmeister]

Seems like fried clutches from the whine.

Also lol at 'stupidest thing ive done'

[Binjammin]

Seems like fried clutches from the whine.

Also lol at 'stupidest thing ive done'

Fried clutches won't whine, they just don't grip. Whining is bearing noise.

[RobertFontaine]

both my wheels chirp.

[shaytanabyad]

Whining is bearing noise.

Which bearings, where?

From what I'm hearing, I think, moving forward, assuming a fried clutch pack is the thing to do.

Thank you for all the help.

[Binjammin]

Which bearings, where?

From what I'm hearing, I think, moving forward, assuming a fried clutch pack is the thing to do.

Thank you for all the help.

Didn't watch the video, but if someone was hearing a whining noise, that's what my post was referring to.

[slippyM395]

Looks like it could be a broken pinion gear, but I'm no expert. Have you tried to spin them on dry? If its a healthy LSD it should be able to do this.

[K Fox]

Would a "fried clutch pack" essentially turn an LSD into an open diff? Any way to check w/out tacking everything out?

Yep. So it's just all tired and worn out. Aside from having to remove the diff to do it, the rebuild isn't too bad. Plus, if you want to, you can upgrade the clutch pack to 40% lockup. Jon (5nail5) has info in one of his threads.

Fox

- - - Updated - - -

Looks like it could be a broken pinion gear, but I'm no expert.

Uh, on this one I think not. Generally a broken pinion would make the car not move - the pinion is the input point for power. So I highly doubt it's that (like 99.9995% sure). I'm about that sure it's the clutch pack - the 'whining' that someone mentioned could easily be the clutches slipping and chattering at a high pitch.

OP - do you know how many miles the car the S3.15 came out of had? Still going to end up needing a rebuild, but I'm just curious.

[shaytanabyad]

Not sure how many miles in the donor car but I look through my records and can try to find out. Anyone have a good source for new clutch packs? I'm not sure if I need 40% but will look into it more.

Found this...

http://www.bimmerdiffs.com/products/...-kit-25-lockup

Thoughts? 2-clutch set gives 25% lock-up and there's a 3-clutch option, which requires some machining, that gives 40% lock-up. I think 25% will be just fine for me.

Also, check out Jon K's AWESOME video here...

http://www.bimmerdiffs.com/pages/guides-videos

[ShapeShifter]

Jon posted some videos on youtube doing this.

[shaytanabyad]

Jon posted some videos on youtube doing this.

Pat - Thanks. I posted a link to one of them above...ha.

[K Fox]

Not sure how many miles in the donor car but I look through my records and can try to find out. Anyone have a good source for new clutch packs? I'm not sure if I need 40% but will look into it more.

Found this...

http://www.bimmerdiffs.com/products/...-kit-25-lockup

Thoughts? 2-clutch set gives 25% lock-up and there's a 3-clutch option, which requires some machining, that gives 40% lock-up. I think 25% will be just fine for me.

Also, check out Jon K's AWESOME video here...

http://www.bimmerdiffs.com/pages/guides-videos

IF you've already got to rebuild it, why not 'do it right'? The 40% option doesn't really have any drawbacks, so why not? I'll be going that exact route when I get a 3.15 myself (hopefully sometime this spring). My $.02

Fox

[Leonator134]

Fox there's a 3.15 for sale in the classifieds.

[shaytanabyad]

... why not 'do it right'?

Honestly, it's a bit scary (to me) because of the machining required. Plus it's a bit more expensive... But I might...ha.

[me78569]

Does the s on the case itself mean lsd or is it only a s on the tag?

I seem to remember my 3.15 lsd having a s on the case, but I don't remember the stocker.

[gixxerboy63]

Check this out:
http://diffsonline.com/bmw-540-diffe...l#.UuxUqdiYa4Q

they also have 6speed Getrag transmissions for our cars
http://diffsonline.com/getrag-6-spee...l#.UuxVj9iYa4Q

Cool stuff

Gixxer wants^

[Hofmeister]

Does the s on the case itself mean lsd or is it only a s on the tag?

I seem to remember my 3.15 lsd having a s on the case, but I don't remember the stocker.

Both mean that. My current lsd had 2 S's on the case.

[me78569]

thanks for the insight

[Hofmeister]

thanks for the insight

Lsd cases are also painted black.