Missionary

Hi Folks.

I am installing a Quaife and need to to re-shim as the backlash went from 0.10 to 0.18mm.

I haven't touched the pinion but I am having to start from scratch on the carrier with a set of ground cir-clips I got from Autotech.

What is the fully assembled preload setting for the 215?

Pinion spec range
Carrier spec range

whipplem104

You should still be fine at the new backlash. .18mm is only .006-.007"

Missionary

I am going to shim it to within spec. 0.06mm to 0.14mm. I am thinking the carrier bearings will be about 1.0 - 1.2Nm. Anybody with access to the factory setting?

whipplem104

There are no factory specs for this differential or any rebuild procedure from Mercedes. You get a whole differential. You cannot even buy most parts for it. Seals is about it. I have cross referenced some of the newer diffs to older cars that used the same parts but that is a pain and you need to know what diffs came in what car and go hunting.
If you are just adjusting lash then all you need to do is have the total snap ring thickness be the same to have the correct preload. Then adjust the thickness from side to side. So take .04-.12mm off the one side and add it to the other side.
Also if you spread the case to get the snap rings out then you have to be careful not to spread it to far as that can effect your setup as well.

Missionary

I had to re-shim it as the original carrier had different bearing land settings to the Quaife. I could feel the cir-clips were harder to get in as well so using the original pack total will be too tight.

There will be specs on this just a matter of finding someone with the access... Daimler maybe? The 215 axles are all the same.

E55Greasemonkey

Mercedes does not publish these specs to the dealerships, the differentials are "not serviceable" like whipple said. When something goes wrong you get a complete unit, assembled from MB.

Missionary

The tech's who put them together will know. I wonder if Daimler is more forthcoming. Dana from Wavetrac is looking into this while we speak.

whipplem104

Mercedes shares nothing. They do not even like to tell the techs very much of anything. Even corporate level people really do not have very much access to info. The only way you would be able to find the actual info is to measure it yourself. Like I said you could easily measure the total preload. If the quaife is thicker and all you have to do is put a thinner shim in to reduce the lash on the one side. Measuring was a little easier with the bolt on side covers. but with the c clips you need to measure the original case spread. Measure with the c clips out and the c clips in and the difference is your preload. Make it the same on the new unit. To make this even a reasonable effort you need to order bunch of snap rings and have them knife edged to about .001 steps down from factory. Have a bunch. Because when you adjust preload it will also adjust the lash at the same time. So you need a lot of adjustment to move around back and forth. I used to do a lot of the older diffs and they had steel shim plates and it was a long process to set everthing up.

Missionary

Yes, that is exactly what I have done. The cir-clips have arrived but I don't have a engineers flat to get carrier bearing land dimensions from both carriers. I did not measure the fully assembled preload just the backlash on disassembly.

I had a discussion with the Timken manufactures of the bearings and it seems rolling torque for a particular bearing is calculable based on rolling speed, lubrication and cooling. It looks like .2mm preload and around 1.1 - 1.2Nm is the sweet spot for maintaining the tight backlash settings that these units run without introducing excessive heat.

If anyone is doing this job at the moment it would be interesting to see what the actual numbers were on a factory unit.

Missionary

I settled on 0.21mm preload after consulting
http://www.jp.nsk.com/app01/en/ctrg/...sk_cat_e728g_7
http://www.timken.com/en-us/Knowledg...r-Bearings.pdf

This worked out at 1.2Nm rolling torque lubricated starting torque was up around 2.1Nm. The feelometer agreed as well and nice to have the back lash dialled in at .008 - .009mm rather than .018mm. The contact pattern was very slightly drive toe/coast heal but nicely centred vertically and no where near the edges.

I also de-burred the ring gear flats while I had it out. Happy to have bottomed out all the loose ends.

carguyshu

where did you guys get the different c clips? I need some for my 03 SL55 and when I google autotech I just see a website that has VW parts.

Missionary

I got a whole set from wavetrac.

JoeJErnst

Here's a direct link to the product page of their catalog:

http://autotech.com/index.php/185wk-...84-4-22mm.html

Alex L

Are these MB/Chrysler shims (from Wavetrac or Autotech)? May need shortly to set the backlash in my own diff.

JoeJErnst

They are probably MB snap rings, but they have been machined to varying thicknesses. If you order some from MB they will come full thickness and won't do you any good until you grind them. FWIW, I was able to take .004" off my old ones by hand, but you won't be able to do that with a new one; it's WAY too thick.