300CE Differential Swap

[AustinsCE]

I know theres a bunch on this, but I want to be 100% before going through with it. First, is it as easy as 1-2-3 like everyone says, just switch em out then calibrate the speedo? Is LSD even important? Which years, and models will work on a 1992 300CE, like I'm pretty sure the TE/D will and its got like 3.27, but people talk about 3.62? whats that from? anything in between? I dont have ASR if that makes any difference. Any help is appreciated.

[Oldbeaver]

Hello,

I saw your question, unfortunately, I cannot answer it. In fact, I am trying to do about the same: change the diff I have (which is 3,07) for one with 3,46 or higher (W124 1989).

My difficulty is to find one, here in my country. Something that would help is to know if other models such as W202 will fit in my car.

Where did you get the list of the suitable differentials?

Good luck,

José

Originally Posted by AustinsCE

I know theres a bunch on this, but I want to be 100% before going through with it. First, is it as easy as 1-2-3 like everyone says, just switch em out then calibrate the speedo? Is LSD even important? Which years, and models will work on a 1992 300CE, like I'm pretty sure the TE/D will and its got like 3.27, but people talk about 3.62? whats that from? anything in between? I dont have ASR if that makes any difference. Any help is appreciated.

[t walgamuth]

There is a table floating around here. Try searching under differential table.
there is a big thread on limited slip diffs in which it is posted, also a thread on diesel geeks put 247 rear in 300td, I believe.

Tom W

[JayRash]

I have the M103 w124 which came with 3.07 ASD Diff, when that diff gave up i changed it to the 3.27 diff with no probs what so ever, just had to adjust speedo. dunno if this is the same for even shorter diff, only worry is the abs speed sensor. Teath count for the 3.07 : 3.27 is the same.

[RBYCC]

Originally Posted by AustinsCE

I know theres a bunch on this, but I want to be 100% before going through with it. First, is it as easy as 1-2-3 like everyone says, just switch em out then calibrate the speedo? Is LSD even important? Which years, and models will work on a 1992 300CE, like I'm pretty sure the TE/D will and its got like 3.27, but people talk about 3.62? whats that from? anything in between? I dont have ASR if that makes any difference. Any help is appreciated.

If I recall the 3.62 was an option on some 1986-1987 diesels, but is very difficult to find...
The 3.27 are fairly easy to locate as they came in the TE and also the 260E.

[AustinsCE]

I actually happened upon a gray market unit from a Euro 300CE potomac was selling, they even had 3.9X-4.X from race cars at the time!

But, the 300SL/SL320 and SE/L have the 3.69, as well as other 3.4X ratios, if I'm not mistaken, dependent on options.

Mine in particular is for the asr/asd? with 2 sensor holes, that I don't have, but I only lost ABS which I don't particularly care about. If I had it to do over, I'd probably have gotten the right one, if only to get rid of the ABS light, but it was $100~ cheaper than all the other 3.69's I found. And with a built engine and twin-turbos, and close ratio 5-speed, I might end up going back to the 3.07 anyway, or a 3.27, when all that's ready.

For now, it's still, otherwise, stock. Top speed is only ~130, however, acceleration greatly improved. Estimated 1/4 mile is mid-14's in racing a chipped 2002 S4 and comparing to my other car, the Audi TT 225, which is a 14.7. Jacka$sery can be had by holding the brake and revving. The rear tires start fishing around at only around 1500-2000 rpms, lots of fun. But it, surprisingly, doesn't squeal off the line under normal circumstances as easily as one might expect.

The diff. table is on gsxr's website. Probably easiest to click on his homepage then google search for ".pdf" and differential.

PS there's one on ebay, in Wisconsin. Shipping would be a grip to S America, just throwing it out there.

Ebay

[dakota]

I do not believe that a diff from a 260E or a pre-93 TE will fit a 92 300CE. The M103 engined cars had the smaller 1.1 liter diff case, where as the M104 should have the 1.3 liter case. I do not think they are interchangeable, but i could be wrong. I don't think the diesel W124s had the bigger case either.

[RBYCC]

Originally Posted by dakota

I do not believe that a diff from a 260E or a pre-93 TE will fit a 92 300CE. The M103 engined cars had the smaller 1.1 liter diff case, where as the M104 should have the 1.3 liter case. I do not think they are interchangeable, but i could be wrong. I don't think the diesel W124s had the bigger case either.

I believe you are correct....

[teezer]

is there an easy way to tell which diff is which when out of the vehicle?? ~~~ the 1.1 or the 1.3

[dakota]

I've never looked at the real thing out of the vehicle, so take this for what it's worth...

From the service manual, it looks like the breather is on the rear cover for the 185mm (1.1 liter) diff and the breather is on the case for the 210mm (1.3 liter) diff.

There may be other, more recognizable differences, but that's one thing that I can see from the graphics in the manual.

[ke6dcj]

Originally Posted by dakota

I do not believe that a diff from a 260E or a pre-93 TE will fit a 92 300CE. The M103 engined cars had the smaller 1.1 liter diff case, where as the M104 should have the 1.3 liter case. I do not think they are interchangeable, but i could be wrong. I don't think the diesel W124s had the bigger case either.

All 6-cylinder W124's fit from every year. Even a 6-cylinder W202 diff fits.

On my 1988 300TE, I have successfully swapped the following diffs:

1) 3.07 LSD from a 190E Euro 16v with a cover-swap;
2) 3.06 from a CIS M104 300CE;
3) 2.87 from a W202 C280;
4) 2.65 from a HFM M104 E320;

:-) neil

[dakota]

Like I said, I could be wrong. ;-)

So what you are saying, Neil, is that the outside attach points of the two case sizes are the same? So then it's the internals that can't be swaped, right?

Thanks for the correction.

[ke6dcj]

Originally Posted by dakota

So what you are saying, Neil, is that the outside attach points of the two case sizes are the same? So then it's the internals that can't be swaped, right?

Correct, can't swap internals of 1.1 liter and 1.3 liter

:-) neil