Limited Slip Differential Tag - Where?

[Engr693]

I have a 73 450SL and my data card has the code for a limited slip differential. I have read somewhere that there is a tag on the diff someplace identifying it as such. I cannot locate this tag on the differential. If the tag is not there is there another way of verifying that it is indeed the LSD?

Thanks

[mbdoc]

Should be a metal tag between 2 of the rear cover bolts...tag should say "Special OIL & sperrydifferential" in German.

Removal of the rear cover is the only real way to see if the car has that limited slip differential.

[Engr693]

Thanks for the reply doc...Is it removable or a permanent tag. It looks as if the cover had been removed at one time for maintenance because there is some orange form-a-gasket or something that has oozed out between the mating surfaces of the cover and housing. I cannot find any tag on mine.

I assume this tag is something that could have been lost, misplaced, or forgotten to be reinstalled after the cover removal.

One more question/scenario: Lets assume that the Limited Slip Differential has been replaced with a standard one by a previous owner. Lets also assume that as the new owner of the car I still think it has the original LSD. If I put limited slip differential oil in a non-LSD rear end, will it cause any problems?

If I do remove the rear cover, what would I be looking for to identify it as a LSD? Thanks.

[mbdoc]

With the rear cover removed the LIMITED slip carrier has a set of clutches on the side gears....a non-limited slip has 4 side gears w/o the clutches.

MB limited slip differentials require special fluid (oil).

As I stated the tag is supposed to be bolted between 2 of the bolts...easy to leave off.

[Engr693]

Will any limited slip diff oil work, such as a kind I can find at NAPA or Pep Boys? Or can they only use MB hypoid gear oil?

Also as I asked above, if I by some chance do not have the original LSD still installed and it was changed out to a regular diff. Will filling with limited slip oil damage a standard differential.

If I put both wheels up on jack stands, and I turn one of the wheels, how will the opposite side wheel react? Could this be used as a test to find out if the LSD is still installed? Or if I only jack one side up and try to turn the wheel, what will be the result?

Thx...
Gary

[mbdoc]

MB's limited slip used clutches coated with brass & they alternate with steel clutches..the fluid uses a special additive that allows the brass to expand & grab the steel plates upto about 40% lock-up..

IF regular fluid has been used then the brass plates are worn & most likely there is too much clearance for them to expand & lock-up.
IF the car still has the limited slip you would need to disassemble & replace the brass plates...

[Engr693]

Will filling a standard differential with limited slip oil damage a standard differential? (I would be assuming I still have the LSD installed)

Will any off-the-shelf limited slip diff oil work? Or only MB hypoid gear oil?

As I asked previously...
If I put both wheels up on jack stands, and I turn one of the wheels, how will the opposite side wheel react? Could this be used as a test to find out if the LSD is still installed? Or if I only jack one side up and try to turn the wheel, what will be the result?

Thanks...

[t walgamuth]

does anybody know this answer?

Tom W

[crhenkel]

I do not know if limited slip diff oil will damage the rear diff, I doubt it, but not sure. I do know that you can use the limited slip additive that is available at the auto parts stores instead of the MB limited slip oil. I use it in mine and it still locks up as it should. I use Mobil One syntetic diff oil and add the limited slip additive and it works fine. I guess techmically you should use the MB oil, but technically it is special order and it is very very expensive in comparison. I believe it was over 3 times the cost per liter and it was special order only at my local dealer. I believe if I remember correctly it was something like $30 a bottle. Dont quote me on that, call the dealer.

[Brian Carlton]

Originally Posted by M.B.DOC

MB's limited slip used clutches coated with brass & they alternate with steel clutches..the fluid uses a special additive that allows the brass to expand & grab the steel plates upto about 40% lock-up..

IF regular fluid has been used then the brass plates are worn & most likely there is too much clearance for them to expand & lock-up.
IF the car still has the limited slip you would need to disassemble & replace the brass plates...

Pat, I'm going way back to my days at Chrysler, so, my recollection may not be accurate.

With the wheels elevated and when rotating one wheel on an LSD, the opposite wheel would rotate in the same direction due to the clutches. However, in the traditional diff, the opposite wheel rotates in the opposite direction due to the lack of clutches and the function of the spider gears.

Would this apply to the M/B diffs as well?

[david s poole]

i think that with limited slip diff with both rear wheels off the ground when you turn one wheel the other turns in same direction and with normal diff it turns in opp dir.

[mbdoc]

MOST MB's equipped with LSD's have worn out clutches & won't lock even 10% now days!

The best way to KNOW is by removing the rear cover if there isn't a TAG that states LSD use special oil!

[Dee8go]

Originally Posted by M.B.DOC

MOST MB's equipped with LSD's have worn out clutches & won't lock even 10% now days! . . .

Does this mean they no longer work as they were intended too, but instead work like a standard differential? Does operating them with worn out clutches hurt anything?

[t walgamuth]

no worries, they just don't lock up.

tom W

[Dee8go]

I have no idea what mine are on the 300TD. Do they tend to be the same on a given model/year, or would this have been an option?