Jasonoff

Damn, I didn't realize it was hacked together. Should I be worried?

Ingenieur

Car stationary on ice
Tcs on
Slam throttle
Rears spin
Fronts stationary
Slip infinite rear speed/front
Od does not matter
It looks at the difference
And full throttle but no torque delivered

The system looks at wheel speed ABS sensors
Not road speed
Tire circumferance is not a factor

Car starts to move
Front wheel 10 rpm
Rears 20
Still cutting power
Rears slow to 11
Power stabilizes
Within 10%
You can 'crawl' and crab
If 2% you couldnot do this

Ingenieur

Not as much about the diff as your thought process
If you knew it was hacked you would have someone else do it
But you don't know what you don 't know
Don't sweat it
It's the least of your 'worries'
It's only a car
Just keep your fingers crossed
You can always have someone else do it right
Lol

So are there shims or not?
Lol

Jasonoff

Sure glad we have someone like yourself, who knows everything, to look up to on this forum...

Manofsteelpt

Thx

Ingenieur

for every person like you there is an opposite
thankfully for me

so, do we need shims if end play is excessive?

Ingenieur

drove it today in heavy rain with 50% worn tires
like a different car, much more stable, before it was pretty 'greasy' and 'squirrelly'

Jasonoff

There are no shims to centre the differential.

The differential housing has a groove for each circlip. The circlip holds the bearing cup in place. The tapered roller bearing that is pressed onto the differential mates to each bearing cup. Both bearing cups (I believe a different size per side) locate the differential inside he housing. There is no side to side play. I can draw arrows on my pictures if required.

That link you sent with the shims look like they are used to set pinion depth on a W201. (didn't read through the whole thread..) I don't even think Wavetrack makes a unit for a W201 so I have no clue what Wavetrack sent your installer. They didn't send me anything 2 years ago when we installed mine.

Who knows, maybe there is a way to do some magic to make pinion depth adjustments inside the C63 pumpkin but I didn't dig that far into it to find out. My backlash was within spec before and after so I didn't need to.

But like you said. My diff is just hacked together so it's probably going to grenade anytime now.

whoover

Both pinion and ring gear, in any differential, are adjusted for bearing preload and for mesh. In the MB, pinion bearing preload is set with a crush sleeve and there are, in fact, shims to set the pinion depth. But in this job, the pinion is not moved, so its bearing preload and depth don't have to be reset.

But the ring gear does need to have the same lateral position as it had in the old diff. Both preload and position are set with shims, which might need to be changed because of the swap. Preload torque and position (via mesh pattern) should ideally be checked during reassembly. This is diff 101.

Jasonoff

Where do said shims go?

whoover

As I said, I've never done an MB diff but the shims are normally installed on one side of the carrier bearing or the other, depending on manufacturer. Changing relative shim thickness on the two carrier bearings moves the ring gear laterally while the sum of the shim thicknesses determines preload.

Ingenieur

the MB diagram shows shims and gives >a dozen part numbers for varying thicknesses


I saw the shim kit


not pinion depth, there are no pinion shims
only ones that sit on each side of the diff

Ingenieur

dogs and cats living in harmony!
we agree on something

the shims go on each side of the diff as required to align it on the pinion since it can't be adjusted laterally, only depth/penetration
they are shown in a link I posted (different model, same concept)
MB won't publically share the C63 diff diagram, you have to buy the whole thing
although they supply a shim kit
unless the car has high miles or improper fluid, chances are they don't need replaced

OlegKouz

Can't wait to order mine. No LSD on these cars sucks, will have to hit the track and make up for lost time (literally)

Ingenieur

Do it
Now
The more I use it, the more I like it

Jasonoff

There were no shims in mine (2010) or my buddies (2009).

It's possible some applications have shims if the housing has a +/- tolerance. In my case, there was no way to shift the differential from side to side in the housing.

Since no shims were used in your install it appears it was the same case.

Jasonoff

I wasn't disagreeing with you on the concept of shims. It's how the S2000 differential works. It wasn't the case inside the my or my buddies C63 differential.

That link you posted of diagram 17 was for a thrust washer which is used for setting side/spider gear friction inside the actual differential.

Ingenieur

They are used only when worn
Not installed when new
And very, very thin

With modern metals, manufacturing metods/tolerances and lubricants might take a few 100 thousand miles to need them

Jasonoff

When what is worn?

atypicalguy

This is a great thread. There doesn't seem to be much info online for setting these rear ends up.

I believe the shims are for setting the backlash. Some thicknesses are NLA and require machining down from the thicker ones.

Resetting the pinion is difficult to do properly without special tools, as it is done in a jig at the factory and adjusted for minimum noise, and getting it back to that position after removing it is impossible to do correctly without a jig of some type.

Anyway just wanted to say thanks for posting. It will help me get my wavetrac installed in an older 500SL diff.

kavik

Anyone know where closest good shop for an LSD install near Nashville TN is ?? A few hours drive is fine...

MBNRG

Had mine done by Tony Barber at Turn In Concepts near Cincinnati, OH - ~4 hour drive from you. Great dudes, great shop!
They work on a lot of C63's, and one of their lead techs owns a C63

Another alternative is ShepTrans, a bit further, outside of Akron, OH. Shep himself owns a few AMGs, and is also very meticulous and versed in LSD installation.
Shep installed member Ingenieur's Wavetrac

BLKROKT

Jasonoff

My hacked together Wavetrac has been going strong for 6 years and ~90k km (56k miles).

atypicalguy

thanks. Good to know.