Limited Slip Slips too Much
 

Gentelmen

I have an 88 560 SL with a limited slip differential. The other day I got the right wheel in the mud and the left wheel was on dry pavement. It was harder than expected to get out due to wheel spin of the right wheel. I jaked the car up put it in neutral and spun the left wheel. The right wheel made about 1/4 turn in the same direction and then completly stoped tuning.

I would like to know if there are any service proccedures published for this problem and what is the proper test proceedure for limited slip performance. My CD only has data for a standard rear end.

Thank You
John Roncallo

I know a LSD was standard on 560SEL and 190E 2.3 16V in '88, but I don't know about the 560SL though it seems logical it would have had a LSD standard.

Jack up one rear wheel with the car on a level surface. DOUBLE CHOCK THE DIAGONALLY OPPOSITE FRONT WHEEL!!! Now place the trans in neutral and release the parking brake.

Use a torque wrench and turning a lug nut clockwise, determine how much torque it takes to break the wheel loose and rotate. Be sure you chock the opposite front wheel or you could drive the car off the jack!

A healthy clutch pack should probably be at least 40 lb-ft. The preload is reduced as the clutches wear.

If the breakaway torque is essentially too low to measure with a 150 lb-ft torque wrench, it is probably an open diff.

LSDs can allow one wheel to spin freely - usually with a sudden torque application with significantly different traction coefficients on the drive wheels - like one on ice and the other on dry pavement, and this will rapidly wear the clutch pack. They work best when they are gradually loaded, especially when the is a large difference in wheel traction.

Duke

It does appear the clutch packs are shot. I did find specs that say 59 - 103 ft-lb side gear turning torque in Mitchels Manual. My owners manual says this is a limited slip diferential and does not specify any other differential as an option.

I will be replacing these clutch packs shortly but I was wondeting if anyone might have any experiance with this. There appears to be a reqiurement for three special assembly mandrels 115 589 04 61 00, 116 589 18 61 00 and 116 589 07 61 00. I belive one of these is to hold the clutch pack splines aligned until ready for installation of the axel shafts. I was wondering if using my axel shaft assemblies would suffice in this case. Are the others really necessary and what do they do. Mitchels is very indescript in the write up. I do have a lath and if these are simple shafts I could just make them. Also asside from the clutch packs might I expect to have to order anything else that would wear in this case. I would like to order everything necessary to complete the job. For example there appeares to be selective preload washers to adjust the side gear torque. Mitchels gives no hint as to how many sizes are available.

Thank You
John Roncallo

John, did you ever complete this project, replacing the clutch packs? I am running into a similar situation and was wondering how it turned out for you.

:)

EDIT: I PM'd John at the end of March, 2007... he hadn't attempted the project yet. Looks like I'm the guinea pig at the moment, lol...

:kid: