Parts Catalog Accessories Catalog Tech Info Tech Forums
 
  Search our site:    
 Cart  | Project List | Order Status | Help    


  Join us November 1st for Casino Night at the Pelican Parts Open House!
Benefiting LuMind - Research and Treatment for individuals with Down Syndrome
Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 02-05-2008, 11:47 AM
Registered User
 
Join Date: Aug 2006
Location: London, Ontario, Canada
Posts: 543
Lightbulb How to convert a GAS W126 to diesel, the definitive thread hopefully.

Hello Mercedesshop, I don't post much, as you can see by my post count however if you see the number of diesels i have owned, I do know a thing or two about these cars.

Every year there is a couple of questions can I put a 617 into a 560SEL or whatnot. Hopefully this thread will answer those questions. I have done an 83 300 SD drivetrain into a 85 500 SEL, and another 83 300 SD drivetrain into a 82 380 SEL, and I am currently finishing my definitive swap, a 85 300 SD with a 4spd manual into a 84 500 SEC euro.

Its a big post so im not 100% sure where to begin, but I'll start by saying, you need to have both cars, Doing it with parts is gonna be a nightmare.

Lets start with the vacuum system.
You need to swap ignition switch because the diesel has a vacuum shutoff on it, it is pretty easy to do, but if its your first time its alittle tricky.
Along with that you run 2 vacuum lines into the passenger compartment. both go to the vacuum shutoff, one goes to a vac source the other goes to the IP.
The rest of the vacuum system from the diesel swaps over easily.

No if you are doing a 500 SEL or 500 SEC you do not need to worry about SLS, however the 560 SEL/C does so you will need to use a 617 from a 300TD or source an alternate pump.

Now the cooling system, Everything from the diesel bolts up, no problems here at all.

Transmission, you have to use the diesel trans, and its wiring is the same, you need to use the driveshaft from the gas car, and change the rear output yolk from the gasser to diesel. its pretty easy but requires a special socket, (30 or 31 mm longshaft 12 point socket)

Differential, no need to change anything here, the 2.47 in the gasser works very well with the diesels powerband.

Fuel system, Remove the electric fuel pump and filter and run the lines up to the front, (one for supply and one for return) no need to change tanks or anything, (you may go threw filters pretty quickly while the gasser tank gets degumed from the diesel). Make sure you swap over the diesel vent line.

Engine mounts, Everything lines up correctly here except for 1 engine shock, either live without it or weld a small braket on the kmember.

Now for the electrical.
Swap the alternator from the gasser to the diesel remembering to change the pulley from the one belt to the 2 belt pulley, (gasser is 85 amps diesel is 65 )

Note on the gasser which wire is for oil pressure and which wires control the coolent temp sender for the gauge and for the fans.

Connect those wires to the senders on the diesel engine.

Glow plug wiring, there are a few ways to do this, I choose to run my gp relay with a switch rather than the key, but thats just me, the gp relay has 4 wires to control it, Supply 12V to the red wire, and ground the brown and it will trigger the plugs.

Throttle, need to use the throttle from the diesel, everything bolts up.

That is basically it, its very easy, because everthing bolts up with very little custom fabbing. you will need the odd connector here and there.

You will not notice a big difference in the weight of the car, so you should not need to do springs. The diesel with a 4spd standard is considerbly lighter than a 500 SEC motor with auto.
__________________
1984 Euro 300SDC, (4spd standard)
1986 Toyota Landcruiser Diesel HJ60 5spd X2

Gone but not forgotten (some sold, some stripped)
1983 300 SD, 1985 300 SD, 1983 240D, 1986 300 SDL, 1985 300 SDL, 1983 300 D, 1984 300 D, 1985 300SD, 1987 300 SDL, 1983 300 SD, 1985 300 TD Euro, 1983 380SEC, 1990 300 D, 1987 300D, 1982 300D, 1982 300D, 1994 E420, 1987 300 TD, 1987 300 D, 1984 300 D
Reply With Quote
  #2  
Old 02-05-2008, 02:55 PM
rrgrassi's Avatar
mmmmmm Diesel...
 
Join Date: Jun 2006
Location: Royse City Tx
Posts: 4,803
Great write up. I guess this also means the easiest alt swap is to use the gasser's alternator instead of having to modify the system for one out of a SAAB.
__________________
RRGrassi


70's SPM #5608 Fairmont A-4 MOW car

06 VW Jetta TDI 145K miles

82 300D 300K My Daily Driver-Warndreicke in the trunk. Trip ODO still working!

90 Dodge D250 5.9 Cummins/5 speed. 260,000
Reply With Quote
  #3  
Old 02-05-2008, 03:22 PM
pawoSD's Avatar
Dieselsüchtiger
 
Join Date: Oct 2004
Location: Grand Rapids, MI
Posts: 14,643
Quote:
Originally Posted by rrgrassi View Post
Great write up. I guess this also means the easiest alt swap is to use the gasser's alternator instead of having to modify the system for one out of a SAAB.
Agreed. I almost bought the 85A unit for a 380 when I needed to replace mine, but it was a lot more expensive than a 65A....so I just went with 65. My original was a 55 though, so I did gain some improvement in having a strong 65 over a dying 55A.
__________________
-diesel is not just a fuel, its a way of life-
'89 420SEL 153k - mine (OC-158,000)
'93 190D 2.2 - 210k - mine (OC-213,000)
'05 C240 4matic Wagon - 136k - wifes (OC-139,500)
'82 300SD 342k -dad's (OC-346,300)
'87 420SEL - 311k - dad's - (OC-314,550)
'01 E320 - 132k - dad's (OC-133,700)
'02 E320 - 158k - brother's (OC - 165,000)
'12 VW Jetta - 14k - Sisters (has begun falling apart)
Reply With Quote
  #4  
Old 02-05-2008, 05:07 PM
rrgrassi's Avatar
mmmmmm Diesel...
 
Join Date: Jun 2006
Location: Royse City Tx
Posts: 4,803
Cool! Thanks!
__________________
RRGrassi


70's SPM #5608 Fairmont A-4 MOW car

06 VW Jetta TDI 145K miles

82 300D 300K My Daily Driver-Warndreicke in the trunk. Trip ODO still working!

90 Dodge D250 5.9 Cummins/5 speed. 260,000
Reply With Quote
  #5  
Old 03-10-2008, 01:55 AM
freeride's Avatar
Registered User
 
Join Date: Mar 2008
Posts: 164
Great!

Now, when can You come to Chicago?
Reply With Quote
  #6  
Old 03-10-2008, 06:47 AM
daw_two's Avatar
diesel enthusiast
 
Join Date: Jan 2007
Location: Germantown, TN
Posts: 5,328
need a donor car....

Okay. So, I have the perfect GASSER, just need a diesel donor car. Am I the only one that would need wife's permission before beginning such a project?
__________________
daw_two
Germantown, TN

Current:
05/2012 1984 300D Light Ivory, Red interior
Cluster Needles Paint
01/2013 1991 350SDL Gray
New Old Stock (NOS) parts

Past:
3/2008 1986 300SDL "Coda"
04/2010 1965 190D(c) "Ben"
& many more
Reply With Quote
  #7  
Old 03-10-2008, 09:34 AM
pawoSD's Avatar
Dieselsüchtiger
 
Join Date: Oct 2004
Location: Grand Rapids, MI
Posts: 14,643
Quote:
Originally Posted by daw_two View Post
Am I the only one that would need wife's permission before beginning such a project?
Nope.
__________________
-diesel is not just a fuel, its a way of life-
'89 420SEL 153k - mine (OC-158,000)
'93 190D 2.2 - 210k - mine (OC-213,000)
'05 C240 4matic Wagon - 136k - wifes (OC-139,500)
'82 300SD 342k -dad's (OC-346,300)
'87 420SEL - 311k - dad's - (OC-314,550)
'01 E320 - 132k - dad's (OC-133,700)
'02 E320 - 158k - brother's (OC - 165,000)
'12 VW Jetta - 14k - Sisters (has begun falling apart)
Reply With Quote
Old 03-10-2008, 09:34 AM
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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 08:08 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page