Is there a final say - w123 with limited slip?
 

My 1984 Euro 280E has it. Did any (US or Euro) come with w123? I've searched many forums and can't seem to come to a conclusive answer.

USA W123 models did NOT ever have limited slip!

What about Euros?

One of my 300CD's is an American, and it HAS a limited slip in it, as well as a host of other goodies, not usually seen, on American versions. Kinda weird car, but definately, NOT a Euro car....Unfortunately. The car is all stock, as delivered which is what makes her so strange...Maybe she was custom spec'ed by the first owner, and ordered with certain options..I don't have any idea though. Any input?

Some of them have ASD instead of ASR.

What years was ASD used?
What years was ASR used?

Based on what I can find, a limited slip diff was available to the w123s in Europe. Any confirmation of that?

What's ASD?
What's ASR?
Who am I ..?
What am I doing here?
Why am I duct taped, to a chair?
I'm not familiar with what ASD, or ASR means..

THERE wasn't ever a USA model that came with limited slip..NONE.

That includes truckinik's 1984 300CD.

ASD & ASR didn't even come to the USA until 1991!

Yeah sure, Just like when they say that no Skylines are, or ever were brought into the US also.. There's always gonna be some, and I know mine can't be anywhere near the only one with a limited slip in it. Don't forget also, that I do live in the North East, and a lot of people up here like to have certain features on their cars, for winter weather, so it is entirely possible it was an ordered package, by someone. I've run my Vin through MB.USA already, and have varification of it at home....But never mind, it doesn't matter...

i have never seen a 123 euro or us with lsd.

tom w

What started me on this question was a conversation with the ex-owner of AMG of Missouri (the importer of my car). He said that every six-cylinder they brought in had an AMG mild to hot cam and a limited slip differential. "They all did," he sternly said.

So I tested my car today to see if I had the LSD - I most certainly do; 100% positive I do. So then the question is raised - is that LSD from MB or AMG? When I run my VIN through the Russian Vin Decoder, I don't get any option codes specifying a limited slip.

That's why I asked.

My 560 SEC AMG Euro, has limited slip in it. I know it didn't come this way from MBZ. I've got the AMG paperwork for the car with the list of mods AMG made to the car. Pretty cool. There's also no doubt about it when you MASH the gas pedal and both rear tires spin and smoke all over the place....LOL.

now i think a lot if not all 560s have lsd.

but not 123s.

tom w

are you saying there are amg 123 280s?

tom w

Barry over at Richmond Mercedes, in Richmond, Cal. tried to sell me an AMG 280 CE, for a lot more money than I thought it was worth to me. The car most definately has a limited slip in it also. He actually used THAT as one of the selling points, in his sales pitch, along with a lot of other features. He told me it is, in his words, "The only AMG 123 COUPE in existence, and a little old lady, in the San Fran area owns it, and wants $110k for it." But it is supposedly the ONLY AMG 123 COUPE ever built. So I guess there's one in existence...Coupe anyways.

Yes. Barry Taylor told me he knows of two AMG w123s that did not have the 5.0 (mine is now the third on his list), Richard Buxbaum (ex-Pres/Founder of AMG of NA) told me they exist, and Al Mahanna (ex-owner of AMG of Missouri - my car's importer) said that all 6-cylinder cars that he imported had at least an AMG cam and an LSD; he also stated that he didn't remember importing many 6-cyl cars.

Yes, Virginia, w123 AMGs with a M110 2.8 do exist, and as far as I can tell, I have one (I'm still missing the original Bill of Sale, but I'm getting closer to those papers). Look at the brochure on the following page and it shows the AMG engine kit for the M110: http://www.geocities.com/johan01.geo/AMG/

PS - Option code 256 is the code for the w126 limited slip - that was easy to find.

Wow, Now that's what I'm talking about...Cool.

and how have you determined that yours has the lsd, please?

tom w

Jacked up the rear and turned the wheels in gear. Both go forward.

that is pretty good evidence!

it is an amg though, right?

tom w

AMG installed Gleason Torsen differentials in there cars. If you truly what know, with out any doubt if you have an LSD, remove the rear cover and look. Post a Picture

It is an AMG - therein lied the question. Was it installed by AMG or by MB? I still can't find a definitive answer that says Euros could/could not be ordered with limited slip. No one seems to know for certain.

I know I could open it and look, I'm just trying to avoid that mess simply to satisfy a curiousity.

Check to see if its a LSD mercedes differential or if its a GT differential. AMG installed GT differentials.... not mercedes LSD differentials.

Also, ASD is a hydraulically regulated differential. It will have the same oil canister that SLS equipped cars have in the engine bay. when it detects wheel spin, it will lock up.

ASR is from what I understand something to do with braking when it detects a difference in speed. I don't believe any W123's had ASD or ASR even offered as an option.

it could also perhaps be a lsd from a 126 body.

have you looked for numbers on it?

tom w

If it’s a true AMG, tuned in Affalterbach in the 80s, you should have a Torsen differential, that’s the differential AMG used then. Removing the differential cover will answer your questions, a Torsen is unique, its looks nothing like an LSD.

Again, FROM the " MB factory" no USA version W123 chassis came with limited slip.

IF you are asking about tuner cars go to the performance paddock!

AMG cars were EURO cars until the C36 came out back in 1995 here.

I understand that; I got it. Mine is not a USA version. Hence, the question remains unanswered, and it seems it will continue that way until I open up the pumpkin.

I wish I had a limited slip...

I can't get even one tire to spin. I'd love to have a Torsen in my road racer, but my commuter diesel it's just not worth it.

According to my trusted Diplomatic and Tourist Worldwide Sales Prices/Specifications/Options brochures (ref. years 1979/82/84/85) there was a Limited-slip Differential, M-B option code No. 256, but it was available ONLY for W126s and SLs. The option had to be ordered in conjuntion with code 601 (Special oil for rear axle with differential).

There was no limited differential available for W123s.

The only rear axle option codes available for W123s were:

Code No. 230: Rear Axle ratio 1:3.69, which by the way was mandated to be combined with option Code 646 (Tyres 15" tubeless). This extra cost option was only available for the 300D/230E and 280E models -sedans, wagons and coupes-

Code No. 212: Rear Axle Ratio 1:3.92. Code 646 had also to be ordered and this option was available only for models 240D/200 -sedans, wagons and coupes-.

I have a seen few W123s here with either of those options, they used to easily recognizable because of the 15" tires instead of the 14". But, as far as I know, I have never seen a W123 with a limited-slip differential fitted from the factory.

The limited-slip differential was a popular post-factory option. I have seen it installed on a Holland imported W123 (300TD) and a French 280CE. Several brands were available (as I remember seen several ads on european car magazines at the time).

Hope this helps to clarify the issue.

so if a car came with the optinal 15" wheels, what did they look like?

and if you ordered them did you get taller springs too for more ground clearance?

tom w

Absolutely it does. Thanks for the answer.

The 15" wheels fitted to the models with optional rear differentials were exactly the same as the 14"s.

The light alloy design was the same and the regular wheel with hubcap were also the same design. Although, visually, you could easily tell the models at the dealer garage with 15"s because the tires looked bigger and the cars looked much taller.

I will asume the springs were also different for the cars fitted with 15" wheels. I have been told by the shop manager that each class could have up to 12 to 14 different types of springs (depending of country of origin, original and optional equipment fitted, and factory tires). Just one example: cars fitted with A/C have completely different springs from cars without A/C.

As most equipment is standard in the U.S., I will asumme spring variences are limited, unlike in the rest of the world.

Do they put part numbers on springs, and if so, where?

so would the diff be marked #256? if it is a lsd?

tom W

OK we took the limited slip out of the 190 16v today
 

and installed it in the 123 housing with the 3.69 ring and pinion. Just a test fit, but preliminary measurements suggest it will fit just fine. After taking it all apart we were looking at how the carrier is shimmed in the housing to get perfect meshing on the pinion bearing and my favorite machinist said Viola' or words to that effect and measured the rather large circlips the hold the bearings in the housing and said "these circlips are used to center it....they are different thicknesses." ....and so we measured the ones from the 123 rear and they were 54 and 62 (thousands?) and the ones from the 190 diff were 56 and 60....so both pairs added up to 106. He said ......"they must have pairs of these and pick them in varying thicknesses to center the carrier."

So after christmas he will disassemble the clutches and measure them so I will know what clutches to order. We feel the bearings and races will be fine and so I will be ordering seals and shims (clutches) and that is it.

He was just chortling at the end. He has never had a benz rear apart before but he was duly impressed with the robust nature of its construction.

Hooooohaaaaaa!

Tom W

I think they all should have limited slip. In snow, one-wheel-drive is a cruel joke. Useless.

we took apart the clutches yesterday and measured
 

for wear. Actually my favorite machinist did and I watched and held onto things while he hit them with large hammers and similar important tasks!:)

We measured everything and I will be ordering end clutch rings that are 3.2, 3.4 and 3.6 to make up for the wear in them and in the thin double faced friction discs.

He likes to tease me about how the benz hardware is strange and all but he is truly impressed with the quality of the construction. He said the spider gear shaft on any american made diff you can push out the shaft with your fingers after removing the split hollow shaft locking it in, and pointd out that on the benz you have to press it in and out.

So depending on how long it takes to get the parts I should have a working benz limited slip in my autocrosser with a 369 ratio in a couple of weeks!

Thanks to all who have made helpful comments to keep this moving along.

Tom W

Wow, there is a lot of speculation in this thread. ;) Pretty much everything MB Doc has said is absolutely correct. No W123 was available anywhere in the world with limited-slip from the factory, but yes some may have come from AMG with limited-slip. (And probably a G-T LSD, if it was from AMG.) Or someone may have installed an aftermarket conversion. If it's factory LSD, the VIN will show option code 256 in the datacard, and no, that is not stamped anywhere on the diff. There will be a little metal tag under one of the diff cover bolts, with German text specifying special diff fluid. That's it.

For the record, the only models I'm aware of that came to the USA with true LSD are the 116 6.9, the 190E-16, and all 560SEC/SEL models. The end. A handful of 124 and 140 diesels, and also a 202, had optional ASD, which is an LSD plus some hydraulics to allow 100% lock under 19mph when wheelspin is detected. ASD was more common in Europe than in the USA. The vast majority of US cars with any kind of traction control used ASR, which was an electronic simulation of LSD, but ASR cars have open diffs. ASR will reduce throttle and/or apply the brake to the spinning wheel to mimic the effect of LSD, without pesky diff clutches to wear out.


Tom, about your project: Yes, the large circlips are of various thicknesses, and yes they are used to adjust the backlash. However, they are ALSO used to adjust the bearing preload! You need to measure & set both backlash & preload. Now, I know you're dead set on using the 3.27 LSD carrier with your 3.69 gears, but if it were that easy, Mercedes woudn't have created a different part number for a 3.69 LSD carrier. I will almost guarantee that you won't have enough adjustment with the circlips to correct the backlash with that setup. If you're lucky you might be able to have a spacer machined, but it will be a full custom job. Let's hope I'm wrong though. :o

Finally, about the friction discs. Ordering 3.2, 3.4, 3.6 is too wide of a spread. If you studied the photo below, you'll see that with the rest of the clutch pack replaced, the tolerances on the end discs were in hundredths of a mm, not tenths. I tried going up +0.2 from the old ones, for the same reason you did... "to make up for wear"... but they wouldn't fit AT ALL. Even +0.10 was too much - it would assemble, but refused not rotate; it would bind up. If your worn disc(s) are 3.2 (or less!), then +0.40 is way too big. The good news is that you can machine the back side to make them thinner as needed. I had to shave off a couple of hundredths at a time until it worked properly, which ended up at +0.05 (+0.07 was still too much). Also, remember that the thicknesses may be different left to right... if so, you must retain the delta between sides! Othewise you'll end up with one side too loose, and the other too tight. Note that mine were 0.10 different left to right. I don't know how to measure that if you lose the factory baseline, so I hope yours are the same, or your tech wrote down the number as he took it apart.

:toff:


http://www.w124performance.com/image.../clutches3.jpg

Coil springs have the part number stamped into the last few inches of the bottom coil. Sometimes you can read the number with the spring in the car, sometimes it has to be removed. IF there is an corrosion on that area of the spring, the part number may be difficult or impossible to read. I've seen springs where you'd almost swear the part number was never there, but it's just corrosion that made it vanish...

:stuart:

I will go talk all this over with my favorite machinist.

We were not planning to get new two sided friction discs as you did, so that is making our extra thickness in the one sided disc more in comparison to your situation. Does that sound like an ok decision to you?

We also measured the wear on the non friction discs. That dimension was IIRC .0001". Just putting in all new friction discs including the one sided one would nearly put you back to the original setup with the exception that you would have the wear on the plain discs as extra clearance. So with the pretty small wear on the plain discs as the only thing not restored by replacement, you would indeed have a very slight increase in the one sided friction plate. I think I am seeing this correctly, am I missing anything?

We measured the distances from the mounting position of the ring gear for the 327 ratio and the 369 ratio and they appear to be the same. How thick was the spacer that you needed?

Tom W

Hi Tom,

1) I would not leave the old, 2-sided discs in place. The only thing creating friction are those discs (and the end disc), for a total of 9 friction surfaces. Replacing one, and leaving in 8 old friction surfaces, seems like a recipe for having more slip than limited (i.e., well under 35% lock). ;) If the plain metal plates look OK, those can probably be re-used, but I would definitely replace all discs with friction material on them.

2) With all new friction discs, yes, there should only be a very small increase needed in the thickness of the end plate, possibly less than +0.10 (each side) like mine, and almost definitely less than +0.20... although I'm very interested to find out what your final selection is. When you talk to your machinist, see if he can tell you what the old discs measured, and post that info here if possible. I'd like to compare your numbers to mine.

3) About the position of the ring gear. I can't explain it, but there is something different between the carriers for different ratios that is not obvious. I went through this same thing while helping someone else with a 210mm LSD buildup. He got a carrier from a 2.47 diff, and it didn't work right with his 2.82 gears - couldn't get backlash anywhere near spec. I said yeah, there's a different carrier for 2.82's. So he bought one of those, compared them side by side, and couldn't find any difference in the mounting position. Said they appeared identical. I encouraged him to try the new/2.82 carrier anyway, even though it looked the same as the 2.47 carrier. Sure 'nuff, the 2.82 carrier cured the backlash problem, easily set to specs along with preload, and he's now happily frying both tyres. When comparing carriers, make sure you are measuring from the bearing seat to the ring gear flange; not the end of the casting.

4) I did not need any spacers for my setup... I used the correct 2.65 carrier for my 2.65 gearset, and had zero problems.

:o

He felt that the wear was negligable on the two sided friction surfaces and did not warrent replacement.

I will go back and talk with him again, probably today.

Thanks again for sharing your experiences and expertise with me.

Tom W

Any news on the LSD project?

:o

I got the parts in last week. He will be installing them soon I hope. He had planned to work on it Saturday but did not have a chance to do a whole lot.

I will post more later.

Tom W

OK, today we assembled the diff with the new one sided friction plates.

It has excessive free play in the pinion as MBDOC and GSX said it would have. So we will be ordering a spacer to be made next week, either 4.9 or 5 mm. We will meet back at his shop this afternoon and attempt to measure it so we know how thick to have it made.

It is pretty sticky with the new friction plate in it. We don't have the equipment necessary to measure the resistance of the clutches so it is a bit of a guessing game. I think we can adjust the resistance some with the lube additives.

comments are welcome.

Tom W

Yep, due to the ratio difference, I figured you'd need a spacer. But it should work with the correct spacer installed (and longer bolts).

The resistance is measured in lb-ft of rotation torque, on the workbench (clamped in a vise). From my experience, you basically have to make it as tight as possible, while still being able to rotate it at all. If it's too tight, it won't rotate... that's not good. The weird part is how touchy it is, a few hundredths of a millimeter can be the difference between just right, and too tight. It's trial and error, and it took me a dozen attempts. If it's too loose, you won't get as much lockup.

I'd be really careful messing with additives to adjust the friction, if the plates get messed up from the wrong lube, you'll have to take it all apart again to replace them. I used OE LSD lube from the dealer. BTW - did you replace all the discs, or just the end disc?

:zorro:

We replaced the end only. The spacer needs to be 4 mm. We just got done measuring it.

Tom W

What was the thickness of the old, double-sided discs? Does the surface at all look 'patchy' or spotty, like in the photo below?

http://www.w124performance.com/image.../clutches2.jpg

My discs were smoother than those in the pictures. Our measurement of the one sided discs was 3.13. The total wear on the two sided discs plus the wear on the plain discs totalled .025 for a total of 3.155 so we figured that we could use the 3.2 one sided disc and compensate for all of the wear and then some. I bought two of the two sided discs so we have that flexibility and we can take material off the one sided disc if needed. Also there is some adjustment available with the friction modifying additive, I believe.

Does this sound OK to you?

Tom W