I'm getting confusing results on EPC with this

According to the New Improved EPC

90 300CE was equipped with 3.27 gearset P/N 126 350 24 39 using the P/N 140 350 27 23 carrier.

91 300CE was equipped with 3.06 gearset P/N 126 350 28 39 using the P/N 126 350 09 23 carrier.

The problem is that both those carrier part numbers cross to early 107/116 cars which are known to be 185mm gearsets. But as far as I know the 3.06 gearset was only available in the 210mm size and the 185 size used a 3.07 gearset. So I cant figure out what is up with that and I have seen many mistakes in the new EPC. To make maters worse there is another 210mm size diff, the 1.4 liter diff used on later 129's and 140's that do not use anything in common with the later 126 style 210mm, 1.3 liter diff.

So this needs more investigation but thank you.

Do both these cars have LSD?

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John Roncallo

Sub par for what?

As far as I am concerned the only thing this style of diff is good for is getting you out of the snow or straight line acceleration. It does that very well with worn clutches or not with the exception of black ice. Putting spring pressure on those clutches at all times would have the effect of wearing out the clutches at an accelerated rate.

If you need a diff for going around corners with one wheel in the air, than this is not the diff to use at all, or to waste any time to modify it into one.

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John Roncallo

Thanks

See my frustrations with trying to do this in my last post. The new EPC is not as user friendly at doing this as the older version.

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John Roncallo

If I'm going to go through the effort to put a LSD in, I want something with a decent amount of bias.

With a worn clutch pack, you end up with what amounts to a pretty low torque viscous clutch. This type of clutch is dependent on oil thickness and will get looser with thin / hot oil.

Does the manual give a breakaway torque? Comparing this to other brands of diffs would give a good comparison. I'm really thinking the viscous clutch action was the intent of this diff rather than a traditional clutch diff given your does not have any preload springs.

Also, a traditional LSD with clutches behind the side gears, has higher breakaway under load due to the spyder hears forcing the side gears outward. This is a feature the MB diff does not have.

The MB has a constant level of torque bias where as a traditional diff has increasing bias under load.

Yes the manual gives a breakaway torque 40-90 NM

This is exactly what MB has.

Where did you get this information.

If you want to put a spring pack on your clutches just buy a phantom grip and put it in with the clutches.

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To see my 129 parts for sale visit:
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John Roncallo

Do you have a pic of the actual diff with clutches installed? My post 5 asked if the clutches were internal to the diff ( where the ring gear bolts on ) / behind the side gears or if concentric to the axle flanges. The yellow part in your post 6 lead me to believe it was concentric to the axle flanges since it does not show side gear teeth.

If internal to the diff like a USA built brand, the wedging action of the side and spyder gears while under power forces the clutches to compress. Take a shim / plate out and rotate the diff while holding both axle flanges. In this case, preload only gives some sort of initial torque bias. If your diff is made this way, installing a spring block would solve the problem. See post 1 here https://www.peachparts.com/shopforum/diesel-discussion/396681-lsd-conversion-kit.html This spring block is what most USA brand diffs use for preload.

If the clutches are outside the diff with some sort of way to engage the diff and axle flange, this would be a constant torque system.

Those who are not familiar with the specifics of the MB LSD should do their homework BEFORE coming to class.

The new EPC is utter garbage. Neither CE has LSD. Both are the larger diff.

__________________

90 300TE 4-M
Turbo 103, T3/T04E 50 trim
T04B cover .60 AR
Stage 3 turbine .63 AR
A2W I/C, 40 LB/HR
MS2E, 60-2 Direct Coil Control
3" Exh, AEM W/B O2
Underdrive Alt. and P/S Pulleys,
Vented Rear Discs, .034 Booster.
3.07 diffs 1st Gear Start

90 300CE 104.980
Milled & ported head, 10.3:1 compression
197° intake cam w/20° advancer
Tuned CIS ECU
4° ignition advance
PCS TCM2000, built 722.6
600W networked suction fan
Sportline sway bars
V8 rear subframe, Quaife ATB 3.06 diff

Pics

The yellow piece is a side gear modeled without the teeth.

Attached Thumbnails

   

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To see my 129 parts for sale visit:
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John Roncallo

Iv'e come to the same conclusion. And I don't see them fixing it for the older cars.

So if that is true. I might be interested in your 91 differential if you still have it. Preferably if you could carefully remove the ring and pinion for shipping or at least the carrier ring and pinion.

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To see my 129 parts for sale visit:
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John Roncallo

Here is some file info that may be of some use:

http://www.peachparts.com/shopforum/attachments/diesel-discussion/148188d1529372759-1987-300td-5-speed-conversion-torque-settings-mercedes-differentials.pdf

Hey Frank, those that can't make the effort to research a simple part like a clutch disc, should not work on cars nor claim to be a MB "expert".

My body of knowledge / skill stretches beyond the MB world and far beyond the automotive world in general so stuff it.

https://www.peachparts.com/shopforum/tech-help/396987-clutch-disc-search.html

Yep, this is the diff type I was thinking of but the drawing and some posts made me want to dig for clarification rather then guess or assume.

What this boils down to is MB apparently does not want much / any limited slip action at light loads. This prevents judder / squawk at low speeds / tight turns.

When you are applying a load, the side gears are forced outwards by the spyder gears compressing the clutch pack. This is why a " loose " clutch pack still works.

Rather than go through the mess of shimming the diff and if you can tolerate the slight chance of slight judder / squawk at low speeds / tight turns, use the spring block someone else posted in https://www.peachparts.com/shopforum/diesel-discussion/396681-lsd-conversion-kit.html

Install this and you never need to shim the diff again as it will now be like a USA type LSD. You can even tune breakaway by changing springs. They likely use readily available stamping die springs.

Using LSD rated oil or the friction modifier additive takes any judder / squawk to zero.

A concern on the clutch plates if they are really brass / bronze. EP oil ( Extreme Pressure ) is generally corrosive to brass / bronze , the sulfur leaches out the soft alloying metals leaving you with porous copper. I wonder what the plate lining really is.

Do you have access to an X ray material ID gun? At old work they would test all incoming material ( aluminum / copper / critical steel ) to make sure it was up to spec. I think this is the one they had. https://www.bruker.com/products/x-ray-diffraction-and-elemental-analysis/handheld-xrf.html

Some specialty metals scrap yards use these, just be sure not to use a spark type as I'm not sure if it will damage the parts surface. https://www.bruker.com/products/x-ray-diffraction-and-elemental-analysis/optical-emission-spectrometry/q4-mobile/overview.html

Thanks Thats a big help. You don't happen to have it in excel, I would like to add gear set part numbers to it.

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To see my 129 parts for sale visit:
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John Roncallo

What it boils down to is MB makes a diff for Luxury cars. You want a diff for something else.

I have one. Not that I remotely ever like it or even the idea of it. But at the time it was the only option available for the 1.4L case SL600 diff that was in my car at the time. That's why I'm going through all this trouble now. Its to get rid of that. I still have it and will sell it to you. It cost my $500 but I will let you have it for $200 because I'm a nice guy.. I see no reason why you couldn't use it to boost the clutch pressure on an LSD diff.

I use a Hewlett Packard Dual Column gas chromatograph

https://www.youtube.com/watch?v=ULATYrEpiJM

__________________
To see my 129 parts for sale visit:
http://stores.ebay.com/The-Mercedes-SL-Store
John Roncallo