Any interest in 210mm 107/126 LSD Clutches
 

Clutch frictions and steels are no longer available for the 210mm LSD diffs used in the 107/126 and I believe some 124's. I am considering having sets sourced through China or possibly the US. Unfortunately that probably means getting about 10 sets.

So I would like to know how much interest there is in these clutch plates. The original MB set would cost ~500 if it was still available. I would expect I could have some Chinese clones made at under $300.00 USD.

So I would like to know how many people here would be willing to commit to buying a set.

JR,

As you have certainly discovered, on these forums there is plenty of "interest"; "commitment" tends to be scarce.
To generate a committed, prepaid group of purchasers will require a firm quote from a supplier. That quote would need to be made at a number of quantity breaks: 20 sets, 50 sets, 100 sets, etc.
Following that, the number of prepaid subscribers by a given cut-off date will determine the price.

The OEM MB sets relied on a selective thickness, 1/2 faced friction for stack adjustment. Producing that piece in a variety of thicknesses would be quite expensive. A work-around could be to make the 1/2 faced friction in only one thickness, and make a steel in a variety of thicknesses as the selective part.

I am working on the quotes. For the 1/2 faced friction I propose using two double sided plates stacked together. That would be about the same thickness as the 3.6mm selective which would be on the heavy side. Then I would use a selective steel against the carrier case. Possibly reduce the thickness of all the steel plates from 1.1mm to 1.0mm and use a selective washer behind the last plate.

The use of two double-sided frictions would seem to be possible, with this caveat: check that a thin friction cannot slip into the relief groove at the inboard end of the teeth on the side gear; the thickness of the OEM single-sided friction prevents slipping into that groove.

EDIT, is this diff built up like a standard USA type diff with limited slip plates inside the unit that the ring gear bolts to or are the discs on the axle flanges , side bearings? If the discs are on the axle flanges, this would still apply just a different execution.

Are the friction plates brass / bronze faced? ( the internally splined ones )

Does this diff use compression springs between the side gears / belleville washer under the side gears for limited slip preload or is preload strictly set by plate / friction thickness?

Assuming the plates are thin but in otherwise good condition, adding a hardened shim under a side gear would give more preload to a spring unit. If this diff does not have any springs, I'd look towards adding a spring.

Your caveat got me. It cant be done. That makes the requirement for a minimum 3mm disk required. That grove is about 2mm.

That really puts a damper on my plan to some extent. Most of the Chinese manufactures are listing 100 plates as minimum order. So I would have to check with them to see if they would accept 10 sets of 8 standard and 2 single sided thick ones as meeting that minimum.

But there are other options here. I have noticed that the steels and friction wear about the same and not too much at that, but enough to loose preload. For the unit I'm working with now I have lost about ~.5mm or 0.020" preload between steel and friction plated per side. That means I can just place one 0.020" 90mm x 60mm washer behind the last steel plate to get my preload back. I'm estimating there to be about 0.4mm material on each side of the frictions of which only 0.05 is worn off.

Mcmaster Carr sells custom made shims of thicknesses from 0.002" to 0.020". They sell for ~$60.00 to $100 for as many as they can get on an 11"x11" sheet. That would be 4 to 9 shims per sheet depending on how what kind of edge distances and staggering they will work with. I'm guessing they will do 9.

If I just had steel plates made in China, they would be dirt cheep and I could reduce my shim size down to 0.010 for my current case and allow margin for further overhauls without having to double up on shims.

Having new clutches made is still not out of the question but you would have to use the selective ones over unless I can strike some kind of deal for the set.

See the pics I posted.

Frictions are internally splined I believe bronze lined.

No springs, Preload is set by plate friction thickness. The concept of sacrificing one plate and using a belleville has crossed my mind, but I think you would really need to sacrifice two plates and place the belleville against a thick steel plate to keep it flat. It would become a science experiment. Mcmaster has a belleville 90mm in diameter by 46 ID which would be perfect but its 7mm thick. It also has a working load of over 7000# so I believe the thickness could be reduced and a solution may be doable but you would definitely need to give up a plate or 2.

The no spring / setting preload with shims is a disaster no matter what company designed it. As noted in your other post, it does not take very much clutch wear to end up with an out of tolerance setup.

Rather than make all new plates, some shims to tighten things up would be way less $. The shims really should be hardened but since this system apparently does not see axial shock loads, a stainless shim might live. Another source for shims are thrust bearing races found in automatic transmissions. Or even off the shelf thrust / Torrington bearing races as these are in the 0.015 thick range.

Brass / bronze bonded steel ( I don't know the official name for this ) is also found on rotary piston hydraulic pumps / motors as a valve plate. If you could find material in the US, cutting this on a laser table would be easy if you have a CAD drawing.

Is it at all possible to drill pockets in the yellow splined part then stack an array of compression springs or belleville washers that press on the first internally splined plate? ( and eventually the whole stack ) Maybe some springs behind the eared disc? Maybe both of only a belleville or two will fit.

I don't know about that probably true for motor-sport applications but all the MB differentials I have seen with loss of preload s still spin both wheels from a straight launch. I would find it had to believe most of these cars have any preload after 20,000 miles.

The current differential I am working on was not taken apart for traction issues. I is simply an ASD diff that needed to be converted to non ASD as well as a junk yard diff of unknown history as well as a diff that needed to be brought to show room condition.

I just ordered a 0.020 set from McMaster unfortunately they take 2 to 3 weeks to get back. Price is not bad. I'm even having them made like on of the steel plates with the ears on them. Why not they don't charge any more for it.

I agree, the shim solution should suffice but plates should be really cheep source from China, possibly cheaper than shims from Mcmaster. In cases where the plates are worn more than mine new plates may be an option to use to avoid having to stack shims as Mcmaster only does up to 0.020". The other reason to replace the steel plates is that they don't wear evenly. Like the clutches, measure them in three places and get three different numbers.

As far as pocketing the side or using belleville, I will pass .

I just do not get why you would spend any money or time on those lsd units. They at best last for around 3 trips around the block and so you have a fairly low bias unit for a short period of time for even if you get the clutches down to free they still have to taken out and rebuilt. So why not just invest in a wavetrac or quaife unit and be done for ever?

I am coming to the same conclusion. Between the PIA to find a diff with a LSD carrier that will fit the 2.65 to 3.06 gear sets and then the fact that it really needs to be refreshed with new clutches that are NLA I certainly don't see myself doing this again. The only diff I'm aware of that had that carrier in the states was the 350SD's with ASD and those are hard to find. If the junk yard knows what he has they will be $500 + about $100 shipping. I was fortunate enough to get this one for about $350 delivered.

However for the non track minded users. Sticking a shim behind the last plate in the carrier is a no brainier while you have one apart. Even without shimming all my 107's were able to leave two even stretch marks for the 1/4 mile track. Including the junk yard unit with the 2.47 ratio I have in the car now.

But I still need to find cars with 2.82 or 3.06 gear ratios to harvest the gears form. Does anyone know what those 210mm gear sets were used in the states besides the 350 SDL. I know the 2.65 was available in the early 129's

One other part that needs to be found when changing gear sets if you want to maintain ABS is the input speed sensor tone ring. Then are NLA. Fortunately for me the 2.82 diff from the 350SDL had ABS and I have this tone ring which I can use to make copies of.

My 91 300CE has a 210mm 3.06. FWIW, my 90 has a 3.27

Just go to epc or whatever it is called now and cross reference the gears. But 3.06 are mostly in the 91 up coupes all the e320 sedans and wagons had 2.65 for the most part. I am sure there are some exceptions. 2.82 is I think 500e and some r129 sl500. I am sure more. 210mm ring gears where used all the way up to 210 and some 220 chassis. Oh and clk w208. 55. might be good for upper 2.--.

Then you will end up with a sub par system.

The clutch packs apparently don't compress much so the window between tight and loose is very small. A spring maintains pressure over a wider total thickness range. Except for a clutch type locker or MB ASD any diff that has clutches has springs.

I'd drill the yellow part then arrange small springs / washers in a circle like an automatic transmission clutch drum piston return spring. The goal would be to set clearance at spec with full bind like the springs are not there then the springs would maintain compression as things wear.

Tie rods and ball joints use a spring / thick rubber ring to maintain zero clearance so this concept is in common use.