STD
W123 differential options - Printable Version

+- STD (https://www.superturbodiesel.com/std)
+-- Forum: Tuning (https://www.superturbodiesel.com/std/forumdisplay.php?fid=6)
+--- Forum: Drivetrain (https://www.superturbodiesel.com/std/forumdisplay.php?fid=9)
+--- Thread: W123 differential options (/showthread.php?tid=2214)



W123 differential options - bmwpowere36m3 - 02-02-2011

I wondering what my options are... currently I have a 2.47 diff installed in my 300CD (turbo). I'm not sure where it came from (W126 or R107) but it’s an open diff with a 210mm ring gear. We had to swap the diff cover from the original diff for it to bolt into place.

Right now I feel like the ratio is a little too low. While on the highway the revs are low... the motor seems to be lugging a little. In 1st, 2nd and 3rd gear the car moves decently, in 4th it really struggles to gain speed till you get to about 3k RPM. Also my speedo is pretty off now.

I'd like to keep this larger diff as I have a 560SL diff (2.47 LSD) that I'd like to use. However what are my options in terms of diff ratios that I could use in this diff?


RE: W123 differential options - DeliveryValve - 02-02-2011

Unfortunately I believe that 210mm carrier only allows for a 2.24 and 2.47 gear set. The next step up 210mm carrier would be in the 2.65-3.07 range.


.


RE: W123 differential options - ForcedInduction - 02-02-2011

The W123 diff mount has only the 3.96, 3.69, 3.58, 3.54, 3.46, 3.07, 2.88, 2.47, and 2.24 ratios.

Your best option is to change to a 2.88, that will retain decent 4th gear acceleration and have a matching speedo available. The 617 just doesn't have enough torque to use a 2.47 or 2.24 adequately and the MPG difference over a 2.88 is very small.


RE: W123 differential options - Biohazard - 02-02-2011

I recently swapped a 2.88 into my dads W123 that is almost completely stock. He is running taller tires in the rear (225/55R17) and has not mentioned anything about poor acceleration in 4th gear. He has been very happy with it so far!


RE: W123 differential options - dieselboy - 02-02-2011

What cars came with the 2.88, 2.47and 2.24? My 3.07's are annoying.


RE: W123 differential options - DeliveryValve - 02-02-2011

(02-02-2011, 08:09 PM)dieselboy What cars came with the 2.88, 2.47and 2.24? My 3.07's are annoying.

2.88 came on 1985 300D/300SD

Here is a list of w126 differentials I compiled. (may need additional updating) 1st generation will fit the w123, 2nd gen will not.


1st Generation
Years, Model, Engine, Differential Ratio, Differential Case Size
1981-1984, 300 SD, OM617.951 3.0L I5, 3.07, 1.1 Liter
1985, 300 SD, OM617.951 3.0L I5, 2.88, 1.1 Liter
1984-1985, 380 SE, M116.963 3.8L V8, 2.47, 1.3 Liter
1981-1983, 380 SEL, M116.963 3.8L V8, 2.47, 1.3 Liter
1982-1983, 380 SEC, M116.963 3.8L V8, 2.47, 1.3 Liter
1984-1985, 500 SE, M117.963 5.0L V8, 2.47, 1.3 Liter
1984-1985, 500 SEL, M117.963 5.0L V8, 2.47, 1.3 Liter
1984-1985, 500 SEC, M117.963 5.0L V8, 2.47 /(Euro) 2.24 LSD/(Euro) 2.47 LSD, 1.3 Liter

2nd Generation
Years, Model, Engine, Differential Ratio, Differential Case Size
1989-1991, 300 SE, M103.981 3.0L I6, 3.46 1 Liter
1988-1991, 300 SEL, M103.981 3.0L I6, 3.46, 1 Liter
1986-1987, 300 SDL, OM603.961 3.0L I6, 2.88, 1.1 Liter
1991, 350 SD, OM603.97 3.5L I6, 2.82, 1.3 Liter
1990-1991, 350 SDL, OM603.97 3.5L I6, 2.82, 1.3 Liter
1986-1991, 420 SEL, M116.965 4.2L V8, 2.47, 1.3 Liter
1986-1991, 560 SEL, M117.968 5.6L V8, 2.47 ASR/2.47 LSD/2.47, 1.3 Liter
1986-1991, 560 SEC, M117.968 5.6L V8, 2.47 ASR/2.47 LSD/2.47, 1.3 Liter



RE: W123 differential options - dieselboy - 02-02-2011

Awesome!! Thank you I know of 3 '85 Cali cars down in chula vista ecology and it's 50% off this weekend!


RE: W123 differential options - bmwpowere36m3 - 02-03-2011

I would like to retain an LSD... so ideally I would need to find a 2.6 to 2.9 diff ratio in either 185mm (swap it into the orignal housing) or a 210mm and swap it into the R107 housing. So basically did mercedes ever offer a 2.6 to 2.9 LSD diff?


RE: W123 differential options - DeliveryValve - 02-04-2011

(02-03-2011, 05:05 AM)bmwpowere36m3 I would like to retain an LSD... so ideally I would need to find a 2.6 to 2.9 diff ratio in either 185mm (swap it into the orignal housing) or a 210mm and swap it into the R107 housing. So basically did mercedes ever offer a 2.6 to 2.9 LSD diff?

Well that gets tricky or expensive. You can buy brand new from Mercedes w124 LSD carriers. You can get them for a 2.65, 2.87 and 3.07. But each carrier for each ring gear has it's own part number. The main issue is whether or not you can fit and correctly shim it in a w123 housing. I know w201 190 16V 3.27 LSD will fit with custom shims.

For the 210mm, a 2.65 LSD found in w116 6.9 was offered. That particular carrier can accept 2.82 3.06, and 3.07 gears. Again you can get this carrier brand new from Mercedes. But they are way over a grand to purchase.


.


RE: W123 differential options - bmwpowere36m3 - 02-04-2011

I saw a post by a user GXSR, that mentions using a 1995 E300 ASD diff and a '85 300D/SD diff to have a 2.88 LSD.


RE: W123 differential options - winmutt - 02-06-2011

I have a 2.88 in my 85, love it.


RE: W123 differential options - cannonballSDL - 02-07-2011

(02-06-2011, 11:19 PM)winmutt I have a 2.88 in my 85, love it.

Is yours from a SDL? did you swap the gear set or the whole pumpkin?


RE: W123 differential options - winmutt - 02-07-2011

Mine is an 85, 300d they all had 2.88. Non LSD.


RE: W123 differential options - Imaginos - 03-20-2011

Would a 2.72 from either 107.026 (450SLC) or 107.046 (500SL) fit the W123?


RE: W123 differential options - ForcedInduction - 03-20-2011

Yes but it would be of no benefit. It would make the car very slow to accelerate, lug the engine too much on the highway for it to increase economy and too tall to raise top speed with stock engine power.


RE: W123 differential options - Imaginos - 03-20-2011

Oh yeah, I know. Was just asking would it physically fit.

I do think though that something like 300 Nm (@2400) of toque and VGT would be sufficient. On the other hand I could be wrong too. Smile


RE: W123 differential options - RonB - 06-10-2011

(02-02-2011, 05:33 PM)ForcedInduction The W123 diff mount has only the 3.96, 3.69, 3.58, 3.54, 3.46, 3.07, 2.88, 2.47, and 2.24 ratios.

Your best option is to change to a 2.88, that will retain decent 4th gear acceleration and have a matching speedo available. The 617 just doesn't have enough torque to use a 2.47 or 2.24 adequately and the MPG difference over a 2.88 is very small.
I'd love to find a 2.88 here in Australia,as we only got the regular 300D with the 3.46 diff .Confused
American market turbo 300's had the 2.88 from Oct. 1984 .
3.46 means a top speed of 150kph and a 0-61 time of 17secs Vs 170kph top speed for the turbo with 2.88 and 0-61 of 14 secs.




RE: W123 differential options - bmwpowere36m3 - 06-20-2011

For simplicity sake is it possible to swap over a 3.07 (just) ring and pinion gear set from a W124 300E diff into my W123 diff (currently 3.46). Both are 185 mm, I'm just not sure on the spacing on the carrier.


RE: W123 differential options - charmalu - 06-22-2011

(06-20-2011, 01:26 PM)bmwpowere36m3 For simplicity sake is it possible to swap over a 3.07 (just) ring and pinion gear set from a W124 300E diff into my W123 diff (currently 3.46). Both are 185 mm, I'm just not sure on the spacing on the carrier.


W123 already has the 3:07, why go to all that trouble? 82 - 84 w123. maybe the W126 SD of those years have the 3:07 also.

Charlie


RE: W123 differential options - bmwpowere36m3 - 06-22-2011

(06-22-2011, 12:30 AM)charmalu
(06-20-2011, 01:26 PM)bmwpowere36m3 For simplicity sake is it possible to swap over a 3.07 (just) ring and pinion gear set from a W124 300E diff into my W123 diff (currently 3.46). Both are 185 mm, I'm just not sure on the spacing on the carrier.


W123 already has the 3:07, why go to all that trouble? 82 - 84 w123. maybe the W126 SD of those years have the 3:07 also.

Charlie

A few reasons:
  • I already have the diff ($ free)
  • I would only replace a few seals (~$20)
  • Learning experience (note: I am very mechanically adept and have done a lot of projects, just not a diff)
  • Can't find a W123 diff or someone who's parting a car in my area (CT) either on craigslist, ebay or carpart and there is no good junkyard or PnP in CT

However, I might not even go through with it... looking at the FSM, I have the later-style W123 diff w/o the carrier bearing side covers. So the process of setting carrier preload and backlash is much more difficult since it involves spreading the case a certain distance and swapping snap-rings (of different thicknesses).

I checked the P/N's between the W123 & W124 3.07 gearsets they are both the same with the expection that the W123 starts with 123 and the W124 starts with 124.


RE: W123 differential options - Mylesofsmyles - 07-26-2011

(11-22-2010, 02:33 AM)ForcedInduction
(11-22-2010, 01:19 AM)Mylesofsmyles w123 TD

If you want power or plan on ever swapping a 606 get a W124 300TD.

(02-02-2011, 08:25 PM)DeliveryValve
(02-02-2011, 08:09 PM)dieselboy What cars came with the 2.88, 2.47and 2.24? My 3.07's are annoying.

2.88 came on 1985 300D/300SD

Here is a list of w126 differentials I compiled. (may need additional updating) 1st generation will fit the w123, 2nd gen will not.


1st Generation
Years, Model, Engine, Differential Ratio, Differential Case Size
1981-1984, 300 SD, OM617.951 3.0L I5, 3.07, 1.1 Liter
1985, 300 SD, OM617.951 3.0L I5, 2.88, 1.1 Liter
1984-1985, 380 SE, M116.963 3.8L V8, 2.47, 1.3 Liter
1981-1983, 380 SEL, M116.963 3.8L V8, 2.47, 1.3 Liter
1982-1983, 380 SEC, M116.963 3.8L V8, 2.47, 1.3 Liter
1984-1985, 500 SE, M117.963 5.0L V8, 2.47, 1.3 Liter
1984-1985, 500 SEL, M117.963 5.0L V8, 2.47, 1.3 Liter
1984-1985, 500 SEC, M117.963 5.0L V8, 2.47 /(Euro) 2.24 LSD/(Euro) 2.47 LSD, 1.3 Liter

2nd Generation
Years, Model, Engine, Differential Ratio, Differential Case Size
1989-1991, 300 SE, M103.981 3.0L I6, 3.46 1 Liter
1988-1991, 300 SEL, M103.981 3.0L I6, 3.46, 1 Liter
1986-1987, 300 SDL, OM603.961 3.0L I6, 2.88, 1.1 Liter
1991, 350 SD, OM603.97 3.5L I6, 2.82, 1.3 Liter
1990-1991, 350 SDL, OM603.97 3.5L I6, 2.82, 1.3 Liter
1986-1991, 420 SEL, M116.965 4.2L V8, 2.47, 1.3 Liter
1986-1991, 560 SEL, M117.968 5.6L V8, 2.47 ASR/2.47 LSD/2.47, 1.3 Liter
1986-1991, 560 SEC, M117.968 5.6L V8, 2.47 ASR/2.47 LSD/2.47, 1.3 Liter



For clarification, US SPEC 500 SEC's from 84-85 had a LSD? And this'll fit a W123???


RE: W123 differential options - winmutt - 07-27-2011

The euros did. You are probably better off finding one in a 116. Either way you are going to have to rebuild them and that is $$$$.


RE: W123 differential options - NGARover - 01-07-2012

(07-27-2011, 08:21 AM)winmutt The euros did. You are probably better off finding one in a 116. Either way you are going to have to rebuild them and that is $$$$.


I have a complete 2.24 sitting here I got from vstech. Anyone ever put one this tall into their w123? I was thinking about putting it into my 82 300td...


RE: W123 differential options - RonB - 01-07-2012

(01-07-2012, 01:24 AM)NGARover
(07-27-2011, 08:21 AM)winmutt The euros did. You are probably better off finding one in a 116. Either way you are going to have to rebuild them and that is $$$$.


I have a complete 2.24 sitting here I got from vstech. Anyone ever put one this tall into their w123? I was thinking about putting it into my 82 300td...

i know someone who fitted one into a W123 280E . It's great on fuel once you get it up to speed but it feels like you have a fully laden semitrailer on behind with 46 tons aboard .
Hopeless in other words.