PeachParts Mercedes-Benz Forum - View Single Post

bkc · #1 07-24-2014, 01:02 AM

I've been hesitant to post about my project here, as it moves in spurts. But, now that it is moving along more significantly, here we go. Besides, I may need help!

Anyway, quick summary:
=== donor car
1993 300D 2.5L Turbo w124.128 (wrecked by Domino's driver)
OM602.962 turbo diesel 5cyl motor
722.418 tranny

=== project car
1991 300SL-24 r129.061
m104.981 motor
722.500 tranny
instrument cluster was upgraded by previous owner to the newer, digital panel, in case that matters

(The r129 with my lovely and project-supportive wife!)

=== the plan
remove m104, keep 722.500
install om602

=== current status
* I've pulled the motors and trannies, and am working on figuring out all the wiring and such. Two years ago I didn't know what a socket wrench was, so I've learned a lot along the way (am currently semi-apprenticing at a local shop).

* My local shop is scheduled to do the physical alterations for the motor and tranny to fit, sublet the fuel tank reseal, and alter/replace the propeller shaft and exhaust, starting next week sometime.

=== questions so far
* Will the 722.500 tranny work fine with the om602? They have the same bell housing and bolt pattern, so they physically fit. The 722.500 torque converter has a larger pump bore on the tranny side, but otherwise seems identical to the 722.418 (at least from the outside). Can I just plug the vacuum line from the om602 injector pump in where the vacuum line from the m104 went on the .500 tranny?

* How do I get the HGS (TCM) working with om602/EDS output? Is the diesel speed sensor (144/rotation) signal to/from the EDS compatible with what the HGS/TCM wants? What do I use to indicate engine load to the HGS?

* Is the weight/balance going to be fine with the tranny about 4 inches forward of original? (om602 is shorter, but nearly fits existing mount locations by being about the same place from the front as the m104) I know this will require moving the tranny mount stuff.

* Will be modifying the engine mounts crossmember, as the om602 sits too high and doesn't *quite* fit the existing mount points, hopefully won't have to modify too much else physically besides that and the tranny mount.

* Will any particular diesel mesh filter fit the r129 tank? Seems like any of them should?

* I'm planning to have the fuel tank cleaned and "resealed" to deal with the galvanization concerns

* Still trying to identify various wires that don't seem to match the manuals and ETM diagrams (e.g. a thick black-red with white spots wire). I want to make sure I remove/cap unnecessary wires, but not lose ones I need to keep or repurpose.

* The preglow system seems pretty straightforward to integrate into the starter circuit. But, how can I add the vacuum valve to stop the motor? Would prefer a mechanical method, like the w124, so the motor will keep running even if the electrical system fails (saved my butt in the w124 shortly after we originally bought it)

I have the manuals for w124, r129, and w140, plus WIS. I also have access to Mitchell's OnDemand5. My local shop is not expert in Mercedes, more American and Asian cars. They do handle major projects though and have a machine shop for fabrication.

Thanks for any advice or even just moral support!

-bkc (Lynnwood, WA)