Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 10-27-2009, 02:30 PM
snookwhaler's Avatar
Linesider
 
Join Date: Feb 2009
Location: Treasure Coast, FL
Posts: 1,417
Question 126 rear in 123?

I have read this before and now I cannot find it.

Will a rear end out of a 126 go into a 123? Are there certain years that will or will not fit? Or will it not work at all?

I think I remember somewhere reading that it will work....

__________________
AJ

1985 300D (SOLD)

Reply With Quote
  #2  
Old 10-27-2009, 03:03 PM
H-townbenzoboy's Avatar
Now Y2K Compliant
 
Join Date: Jul 2003
Location: Houston, TX
Posts: 4,338
If by rear end you mean differential, the answer is yes. Differentials from 1981-1985 W126s will swap into W123s. 2nd generation differentials in the 1986-1991 models won't fit.
__________________
'81 MB 300SD, '82 MB 300D Turbo (sold/RIP), '04 Lincoln Town Car Ultimate

Sooner or later every car falls apart, ours does it later!
-German Narrator in a MB Promotion Film about the then brand new W123.
Reply With Quote
  #3  
Old 10-27-2009, 04:26 PM
Banned
 
Join Date: Oct 2009
Posts: 105
You'll have to swap the axle spacer shims but should otherwise be identical.
Reply With Quote
  #4  
Old 10-27-2009, 04:28 PM
oldsinner111's Avatar
lied to for years
 
Join Date: Nov 2008
Location: Elizabethton, TN
Posts: 6,246
Go for a 2:47 rear end from a gasser,and enjoy 37 mpg.
__________________
1999 w140, quit voting to old, and to old to fight, a god damned veteran
Reply With Quote
  #5  
Old 10-27-2009, 04:39 PM
daw_two's Avatar
diesel enthusiast
 
Join Date: Jan 2007
Location: Germantown, TN
Posts: 5,449
Quote:
Originally Posted by oldsinner111 View Post
Go for a 2:47 rear end from a gasser,and enjoy 37 mpg.
Yeah, I wonder who might have one in a 1981 380SEL....

__________________
daw_two
Germantown, TN

Links:
Sold last car --- 05/2012 1984 300D Light Ivory, Red interior
Cluster Needles Paint
New Old Stock (NOS) parts

Past:
3/2008 1986 300SDL "Coda"
04/2010 1965 190D(c) "Ben"
& many more
Reply With Quote
  #6  
Old 10-27-2009, 04:40 PM
snookwhaler's Avatar
Linesider
 
Join Date: Feb 2009
Location: Treasure Coast, FL
Posts: 1,417
Quote:
Originally Posted by oldsinner111 View Post
Go for a 2:47 rear end from a gasser,and enjoy 37 mpg.
I find it hard to believe that I could go from 25/27 MPG to 37 MPG by going from a 2:88 to a 2:47? I could see maybe gaining a little like 1 or 2 MPG on a good day. Maybe with a 5 speed and a 3:46 or something?

I'm actually looking for another 2:88 (mine is shot). A 3:07 would be OK too. I just want one that is not "sloppy".
__________________
AJ

1985 300D (SOLD)

Reply With Quote
  #7  
Old 10-27-2009, 06:15 PM
Banned
 
Join Date: Oct 2009
Posts: 105
Quote:
Originally Posted by oldsinner111 View Post
Go for a 2:47 rear end from a gasser,and enjoy 37 mpg.
Until you correct the odometer mileage for accuracy.
Reply With Quote
  #8  
Old 10-27-2009, 09:09 PM
Registered User
 
Join Date: May 2007
Location: Out in the Boonies of Hot, Dry, Dusty, Windy Nevada
Posts: 9,652
You will have to change the tri flange. the 126 uses a larger flex disc.

You will have to determine the friction pre load on the pinion nut before removing it. then when you replace the 126 flange with the 123 flange, you will now have to tighten the pinion nut to the original friction pre load torque setting.

good time to change the pinion seal as well.

here are a couple threads about the pre load.

www.peachparts.com/shopforum/showthread.php?t=233540

www.peachparts.com/shopforum/showthread.php?t=81784

Charlie
__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

Last edited by charmalu; 10-27-2009 at 09:15 PM.
Reply With Quote
  #9  
Old 10-27-2009, 09:15 PM
Banned
 
Join Date: Oct 2009
Posts: 105
Quote:
Originally Posted by charmalu View Post
You will have to change the tri flange. the 126 uses a larger flex disc.
Only on the V8's.
Reply With Quote
  #10  
Old 10-27-2009, 09:16 PM
Registered User
 
Join Date: May 2007
Location: Out in the Boonies of Hot, Dry, Dusty, Windy Nevada
Posts: 9,652
Quote:
Originally Posted by Les Jenkins View Post
Only on the V8's.

so the I-6 uses the same size as a W123?

charlie
__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works
Reply With Quote
  #11  
Old 10-27-2009, 09:19 PM
Banned
 
Join Date: Oct 2009
Posts: 105
and the diesel.
Reply With Quote
  #12  
Old 10-27-2009, 09:25 PM
Registered User
 
Join Date: Apr 2006
Location: South Florida
Posts: 467
Quote:
Originally Posted by snookwhaler View Post

I'm actually looking for another 2:88 (mine is shot). A 3:07 would be OK too. I just want one that is not "sloppy".
What are the symptoms of yours being "shot"?
__________________
'83 SD, 2x '85 SD
You are entitled to your own opinions, you are not entitled to your own facts.
Reply With Quote
  #13  
Old 10-27-2009, 09:33 PM
Registered User
 
Join Date: Nov 2004
Location: North central Texas
Posts: 2,596
Only W126 diffs up thru 85 will fit.

Also, keep in mind that a lower rpm doesn't mean better mpg. It may now require more thottle (fuel) to maintain the same hwy speed since the engine is now not near it's peak torque rpm curve. MPG may drop.

BTW, I just happen to have a spare 2.88 and 2.47.
Reply With Quote
  #14  
Old 10-27-2009, 10:25 PM
t walgamuth's Avatar
dieselarchitect
 
Join Date: Apr 2005
Location: Lafayette Indiana
Posts: 38,613
Quote:
Originally Posted by Whiskeydan View Post
Only W126 diffs up thru 85 will fit.

Also, keep in mind that a lower rpm doesn't mean better mpg. It may now require more thottle (fuel) to maintain the same hwy speed since the engine is now not near it's peak torque rpm curve. MPG may drop.

BTW, I just happen to have a spare 2.88 and 2.47.
Not likley in my experience. (sorry to disagree, Dan). In a diesel swapping in a taller diff has always worked well for me.

I am running a 307 diff in my 83 240 with euro 300d motor. With the four speed I got thirty highway regularly. I swapped in my five speed and now get 35 36 regularly running 70 to 75 mph.

I could pull a slightly taller gear...maybe a 288 but taking off is already a bit dicey with the 307 rear end.

(the 307 with the 18% od is about equal to the 247). You'll never get 37 running an automatic imho....unless you run about 50 mph).
__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.
Reply With Quote
  #15  
Old 10-27-2009, 10:35 PM
daw_two's Avatar
diesel enthusiast
 
Join Date: Jan 2007
Location: Germantown, TN
Posts: 5,449
Quote:
Originally Posted by Whiskeydan View Post
Only W126 diffs up thru 85 will fit.

Also, keep in mind that a lower rpm doesn't mean better mpg. It may now require more thottle (fuel) to maintain the same hwy speed since the engine is now not near it's peak torque rpm curve. MPG may drop.

BTW, I just happen to have a spare 2.88 and 2.47.
I might have to drive down there with a truck full of seats and some other stuff.

Sorry for the thread, hijack.

__________________
daw_two
Germantown, TN

Links:
Sold last car --- 05/2012 1984 300D Light Ivory, Red interior
Cluster Needles Paint
New Old Stock (NOS) parts

Past:
3/2008 1986 300SDL "Coda"
04/2010 1965 190D(c) "Ben"
& many more
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 05:48 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page