QVHK

Hello All, I got a 1990 300CE 12V and I recently replaced my auto gearbox with a 5-speed manual gearbox (with the related flywheel, new clutch, new clutch master and slave cylinder, differential, etc.). Every thing went fine but the post-conversion performance is discouraging. The car feels somewhat 'soft' - acceleration in 1st and 2nd gear is pretty weak and the car cruise more quietly than before but the car can hardly pull from 4th and 5th gear. The manual gearbox and differential were taken from a 1992 300CE 24V so is it possible that the differential is a mismatch? My mechanic told me that my original differential's ratio is 2.65, but there is no similar inscription on the differential newly fitted to my car. Any advice on what might be the problem and what solution is available? Am pretty disappointed with the outcome of the conversion. The car used to run very well with a very willing and reliable engine (M103).

AMGDave

The gear ratio will be stamped into the differential housing, as shown in this photo (the first numbers are the serial number, the last few numbers are the ratio). You will probably need to clean it up with a wire brush to read this this as it's often covered with grime or rust.

That said... the 1990 300CE (124.051) came from the factory with a 3.27 gear ratio and a 4-speed auto in the USA. In Europe it was also offered with 4-speed manual with 3.27 ratio, or a 5-speed auto and 3.69 gear ratio.

The 1992 300CE (124.051) with 4-speed auto had a 3.06 ratio in the USA. In Europe, it was offered with a 4-speed auto or 5-speed manual with 3.06 ratio, or a 5-speed auto with 3.69 ratio. (The 124.052's went to 2.65 gears in the USA.)

Sounds like you previously had a 3.27 ratio, and ended up with a 2.65 ratio, which would cause the problem. Since this is not at all related to LSD, you should probably start a new thread on this topic, and post a link here so we can follow the progress. Oh, and it would also help if you posted your location (USA, Europe, etc)...


LSD content: I'm trying to obtain a QDF5V to see if I can replicate Whipple's results. I'll post again when I have more info. Thanks again to Whipple for the photos & information!

QVHK

Thanks, Dave. New thread created here https://mbworld.org/forums/e-class-w124/355707-post-conversion-problem.html

the_widebody

carlos, if you are purchasing a genuine 'baby hammer' with the 103 12v 3.2 engine, it will have the larger diff and 3.27 gears with the cluchpacks, as mine has.

QVHK

Thanks. Unfortunately there is no W124 3.2 12V in Hong Kong. Most unsold second-hand Mercedes are shipped overseas, and only those badly damaged ones are taken apart for parts locally. The search for a suitable differential for my 12V CE continues, failing which I shall re-use my original 3.07 differential which should be slightly better than the 2.87.

AMGONLY

To: Dave or anyone who can help!

After reading all the thread, it gets me all confused since there are so many different gear ratio and combination. Dave, you are like an expert, could you help me to find which is for my car.

I have a 1994 E500 W124 US Spec. with ASR. I believe in comes with 2.82 ratio and its 210mm.

I need an ASD or LSD that can go on this car. Could you tell me which one to put on? Or where to find one? Or if you have one that can sell to me?

Thanks.

Andy

QVHK

Hi, Andy. This thread is on limited differential. My other thread on differential continues here. https://mbworld.org/forums/e-class-w...n-problem.html

AMGDave

Hi Andy, I just sent you an email... let me know if you don't receive it!

Thread update: I have the Quaife successfully installed in my 500E now. Photos coming soon...

Motilev

Any updates with the photos?

Which Quaife LSD you used? This one?
http://www.quaife.co.uk/catalogue/products/qdf5v

AMGDave

Yep, that's the one. Here's a photo... not much to see, except that it fits!

John Bicht

Over the last few months I have done some work with our 400E that has transformed the car. It was a nice car, but didn't quite manage what I wanted - a taut sports sedan that was really quick with good ride and feel. Part of it is directly relevant to this thread so I would like to explain my experiences so it might help someone else. We bought the car 7 years ago at 135k miles. Now it has 203k.

Prior to discovering this thread I had no idea that I could fix the two outstanding aggravations of the 400E - that they come with a stupid axle ratio of 2.24, and that they use the ASR system - or at least ours did. I wanted a real limited slip differential and a higher ratio gear set.

I hate ASR, although some like it. I want control of the car - not have control taken away by some stupid electronic idea cooked up by a couple of German engineers. It did not give me any advantage in snow, although open diff Mercedes are notorious for wheel spin in snow. Then trying to go fast it interfered a lot, first applying a brake and then taking the throttle away from my control with some wheel spin in corners.

We had already lowed and stiffened the car with a Sachs suspension kit that was even unavailable 7 years ago, but some friends found me one. I wanted it because I had previous experience with such a kit and it was great. This kit didn't work as well! Until just now. Once the rear suspension was up to original condition, even with 70k miles on the shocks it now feels right.

This project would not have started without AMGDave's posts, and later support, and a bunch of others, who for instance pointed out how to disconnect the ASR. I disconnected the ASR at the three pins in the ASR/ABS module, and I intend to leave it disconnected.

I did the differential and my independent Mercedes guy put everything - including the suspension and sub frame parts - into the car.

I purchased both a new Mercedes pt. no. 126 350 40 23 complete ASD differential carrier, and a used 500E complete center section - differential complete. This has a 2.82 ring and pinion. Beware that east coast parts that have any age to them can be extremely rusty! See picture one below. You should also not that when I bought the carrier, it was the next to last one in Germany.

I had been a mechanic for years when I was in my early twenties, and then later built race cars in England, so I am no stranger to how to do these things, plus we have a modest shop. I had access to W124 service manuals that quite detailed assembly.

On disassembly and cleaning I checked the two carriers and found them to be identical across the bearings and ring gear mounting face, so I expected no preload and clearance problems on reassembly. One tapered roller carrier bearing had a slight dark mark on the race so I elected to change it. With some risk of preload problems on assembly as it turns out that the total stack height of tapered roller bearing of this size can vary .008". I also elected to remove the pinion so I could inspect the bearings and replace the seal. Remember that this assembly looked very untrustworthy and so I was not inclined to take chances.

Removing the pinion was a huge effort! There was some rust between the input spider and the pinion shaft, but I believe (after putting it all back together) that the main problem is the tightness of the press fit use by Mercedes. An 8 ton hydraulic press would not push the pinion out through the spider.

Putting the pinion back I used a new crush disc and washers. I made special pins to bolt into the input spider. We used a 5 foot bar on the bench to hold the input still, and it took a 4 foot bar to tighten the pinion nut sufficiently to get the preload needed. Some really tight fits by Mercedes! Carrier bearing preload was checked by the case expansion technique used by Mercedes. This is quite simple. The bearing on the pinion shaft behind the pinion gear was left in place so I did not have to fiddle with the pinion position. Pinion preload was checked both by feel and using a long and heavy screwdriver stuck through the input spider bolts. When the handle was close to the center the screwdriver did not make the pinion turn. When the screwdriver handle was moved further out it turned. This had been documented before disassembly.

The rust on the case was mostly removed with a needle de-scaler, and the other external parts were glass beaded to remove rust. All was painted. See picture three below.

On reassembly it was found that there was an interference between the new carrier and the case casting. Dave did not have this problem but I did. See picture two below. There is a difference between the two castings at the bottom of the cast well below the breather.

The ASR/ABS sensors were very hard to get out since they had been rusted in. One broke. I hoped that the sensors in the 400E would work and they did.

A bit about ASR/ABS sensors. It seems impossible to find detailed information from Mercedes or Bosch. I put considerable hours of research and finally have reached these conclusions. The control module reads the pulse frequency. The inductive sensors need be close enough to the "tone wheel" so that enough voltage is generated so that the inputs at the module can read them. I found in research that American cars with Bosch sensors used around .020" clearance between the end of the sensor and the tone wheel. When I measured the 500E, I found that it had .5 mm. or about .02". It seems to be a concern that the shims under the sensors be kept with the sensor so as to preserve factory setup. On the other hand the shims are not available in very fine increments so the thing is not a crucial as it might appear. It is likely that the two sensors want to deliver reasonably the same voltage so as not to trigger some other failure mode in the module. As it turns out the 400E sensors fit with about .015" clearance and they work.

We also replaced every rubber bushing in the rear suspension and sub frame, including 500E rear sub frame mounts.

I wondered whether the ASD diff would provide enough slip limiting to be what I wanted. It very much does. With a few hundred miles on it, it has lost it's initial tightness, and somehow just lets you know you have a LSD. On loose surfaces both wheels work together. Great.

I worried that the 2.82 ratio would cause to much engine noise at 75-85 mph which is our Interstate cruising speed out her in Colorado. It doesn't. Wind noise still predominates and I am unaware of the higher revs - about 500 at 75 mph. It makes a beautiful difference in acceleration. Oh, boy does it. I can hardly wait to get down to sea level to see what it does there.

I wondered if the rear suspension would feel better. Oh my did it ever. My wife could feel the difference from the passenger seat in 50 feet! It is taut and precise. And now the shocks feel fine for the first time in seven years. How the loose rear could make shocks feel under damped I am not quite sure.

If the suspension bushings of your W124 haven't been changed in 10 years or 100k miles, replace them all. You can't tell by flexing them with a bar. Remember there are 10 bushings on each side and 4 sub frame bushings. Don't let a mechanic talk you out of it.

AMGDave

Nice work, John! Thanks for the update & photos. Looks great. Just curious, have you driven it with ASR on at all? Also, with ASR disabled, did you pull the bulbs from the cluster so you don't have the ASR light on all the time?


BTW - there are zero of those LSD carriers in Germany now, and there is a note in their computer systems saying something like "Part currently unavailable". Someone would have to actually place an order to see if MB would have a few more built. At the moment, there is no code preventing an order from being placed, so there's still some faint hope for those who would like to replicate this project.

John Bicht

Thanks Dave.

I haven't driven it with ASR, and hope never to. I know you cautioned about this, but I will get back to you after the first snow.

As for the light I am planning to do this as I install the Yellow Box (all sorted out by the way the Aussie company is quite cool), but I was concerned that the "light bulb out" circuit would light up. Do you know if that system looks at internal bulbs - including the Snow Chain switch? The really bummer part is that I waited to get the Yellow Box, and am stuck with a speed vs. speed cheat sheet taped to the dash.

I am truly sorry that the carrier isn't there to buy. That is really a shame. Very pleased I got on with it. Wouldn't others be able to do it the hard way and rebuild an ASD diff. and put it into an ASR case?

AMGDave

My '87 has LSD without ASR. You just have to be careful in the snow - as long as the driver is skilled, you're ok. The rear end is more likely to get loose with LSD as it will (more frequently) break both tires loose instead of one.



The bulb-out module only looks at external bulbs, so there should be no problem at all removing bulbs for any dash lights you wish to be extinguished permanently.



No worries, I wasn't quite ready to build another one yet anyway. I do wonder who scooped it up though. Yes, you can locate a used ASD diff and rebuild it (which is what I did the first time). However, this is not as cost effective (it will end up costing as much, possibly more, than buying a new one) and there's a fair amount of techie labor involved if attempted as DIY, including fabbing some tools. I wouldn't recommed the clutch refresh for an amatuer mechanic. The clutch selection is slightly less of a gamble when rebuilding the 210mm, which is nice, as the inner edge of the disc doesn't wear - this allows you to measure it & order the original thickness. On the 185mm, you can't do this, and have to estimate... NOT fun (don't ask how I know).

The 210mm clutch pack is shown here. I thought about fabbing larger steel plates to increase the lockup, as explained in this photo, but I suspect that would be a lotta work with questionable ROI. Probably easier to just move to the Quaife at that point!

John Bicht

Making new steel plates wouldn't be all that hard. Waterjet cut out steel plates with a lick of surface grind to true them, and done!

Am I being fooled by my new carrier? It has a good few hundred miles on it. Does it stop being such a good limited slip when there is thousands of miles?

AMGDave

It should last a LONG time under street use. My estimate is 100kmi or more if it's not abused. The 185mm LSD in my '87 has 35kmi and still works great. By way of comparison my old '93 300D with ASD (which has LSD internals) was almost totally open with 150kmi on it. Eventually you'll need to refresh the clutch pack, but that should be many years (and many tens of thousands of miles) in the future.

Now for racetrack use (road course or autocross) with nearly 300hp on tap, I really don't know how long the clutches will last. But if you don't track the car, it shouldn't be an issue. Dragstrip use causes minimal wear, for obvious reasons... no worries there.

AMGONLY

Need Help!!!
I've been trying to find the ASD for my E500 (126-350-40-23). But with no luck.
Anyone, anywhere has one that can sell to me?
I'm willing to pay good price as long as the condition is good.
I can accept rebuilt or non rebuilt. Just as long as not very bad shape like rusted or been hit and damaged.

thanks.

AMGDave

First, try to order one new from MB. Last I checked there were zero available in Germany, however that doesn't mean you cannot get one. You will have to actually place an order for one and see what happens. Most likely it will be one of two things - first scenario, MB receives the order, and builds a few more of these, and you get it in a few weeks. Second scenario, they decide they're not going to make any more, your order gets cancelled, and the part number is flagged in their computers as non-orderable (this will prevent an order from being placed in the future). But, you gotta give it a try.

If you don't have a favorite dealer you normally work with, try either the MB Classic Center (Tom Hanson has helped me out before), or for a steep discount try Parts.com (select "Freight-Quote" at checkout to save on shipping fees). In either case, when they tell you "there are none", you have to say "I know, but please place the order anyway and see what happens". Currently it's $1120 MSRP, or $771 + S&H from parts.com.



Assuming you cannot obtain a new factory LSD... my first recommendation would be to get the Quaife. The drawback to the Quaife is the cost (approx $1400 USD) and the hassle of either figuring out what to use for axle clips, or just not using any clips and hoping for the best. Buying the Quaife may be a hassle as well, depending on if you can find one in the USA, or if you have to buy from overseas.

Second recommendation would be to find a used one from an S350 diesel with optional ASD... which will be the proverbial needle in a haystack. All you want is the internal carrier so it doesn't matter if the housing is rusted or banged up, as long as the internals are undamaged (i.e., it wasn't pulled out of a lake or something). These tend to run $300-$500 plus S&H (not cheap on a 100-lb package), then plan on about $400 to replace the clutch pack (NOT a fun job, some special tools required). Do the math - fixing a used one isn't particularly cost-effective.

With any of the above choices, after you obtain the LSD unit (either new factory, new Quaife, or rebuild a used factory one) it will be another couple hundred bucks for new seals, bearings, etc and multiple hours labor to install.

BTW - I'm assuming you're positive the 126-350-40-23 diff will fit your car / housing / gearset / etc. If it's for your 1994 E500 with stock gears, then yes this is the correct diff.


Hope this helps!

AMGONLY

Hello AMGDAVE,
Thanks a lot. I try order from part.com and MB of FT Lauderdale.
But after place order, they all reply back parts not available.
Thats why I'm trying to see if I can find one anywhere either new or used.
The ASD will suit my purpose better than Quaife.

Well thanks anyway.

Please anyone let me know if you have one to sell me.

greengoose

Lots of info on this thread. Im still trying to figure out if I do or do NOT have LSD on my 91' 300D.

Currently I am stationed in Germnay and bought a 1991 300D (US Spec) back in 2007. It now has 360,000 miles on it. Im commuting 120 miles a day and winter is coming. It seems even if I do have a LSD, I would be replacing the clutches due to the high miles on it for it to be effective.

(Is there a quick way to see if my car has LSD by looking at some number on the rear diff?)

rivcal4life

There would usually be a silver tag on the housing that said something about special diff oil in German. I'll try and find a picture I have. It would be viewed from beneath and behind the vehicle, on the lower right hand side.

John Bicht

Some did some didn't. Do you have a switch or dash light with the letters ASD?

Best test is put water in front of one tire and see if you can spin one tire not the other. That tells you whether you will have limited slip enough to work.

Then go buy four Bridgestone Blizzaks. Don't mess around with trying other stuff. These are life savers.

AMGDave

If the car has anything it will be ASD, which is "LSD plus". There will be a square orange warning light in the top/center of the speedometer, and also an "ASD" dash light near the glow plug light. If you don't see either of those - the car does not have ASD (and therefore does not have LSD either).

I'll second the recommendation for four new snow tires... Blizzaks are great, but any "real" snows are better than "all season" rubber for ice & snow use.

ruslan98270

k i found 190e on local craigslist ad, guy was selling 190e with lsd from S-class mercedes i tried asking him how he did it and he got mad at me for not buying it so didn't get any information,

im guessing e420 exles with same year s-class diff

correct me if im wrong

ruslan98270

i was also thinking doing r200 out of 1990 nissan 240sx since it has cover with 4bolts and just make custom mount in front and custom axles and u got one crazy setup, normal LSDs all day long!!!

you need r200 ($150 for vlsd, or open pumkin people throw away and buy 1, 1.5 or 2 way LSD for 600$)

custom drive line ($300 at your local driveline shop)

custom axles ($800 for both)

and little bit of welding

total be like $1500 and you have one nice setup