Builds The Mule: My OM617 swap and other improvements

[DPV7070]

Updated part number for the Bosch voltage regulator

Didn't like the look of the trans tunnel so my dad and I did a little work to it

Also got the fender supports moved out 3/16" and welded. Drilled frame for the support hardware, will tap it and stud the bottom 2 holes.

 

[DPV7070]

Shot the trans tunnel with etching primer. Ready for some 2K urethane primer, wet sanding and more priming. Hoping to get some color on it this weekend. Underside will get the rest of the Lizardskin ceramic insulation I have left over from the firewall project.

 

[RWBeringer4x4]

Wow, that turned out great!

 

[davegonz]

Yeah. Looks good.

 

[78fj40mg]

Nice work!

 

[franklin40]

hey I'm using Home Depot boxes for painting on too!

that looks awesome! looks like I'll likely need to do a similar modification for my tranny. I'm so impressed

 

[DPV7070]

Thanks gents, still a lot of body work to do on it. It's going to look like a diamond in a goat's ass since the rest of my interior is 40+ years old.

 

[DPV7070]

It's been awhile since my last update, but I've still been cranking away at it:

Transmission tunnel is ready for paint. Body work is a PITA!

Twin sticks are complete. Tech note here: be sure to remove the bushings before welding anything. I screwed that up a while back and had to buy new bushings. Knobs will just peek out from the shift boot. I spaced them so they shouldn't rattle. They're even with each other because it feel like/reminds me of pushing in power on a Beechcraft BE-200. Weird I know..

Shock towers are burned in. I used a plumb bob to get them over the shock mounts. I ended up cutting the again as I straightened them too much the first time, so I actually had to put a bit of a bend back in. Fenders clear just fine. About .75" of clearance on the driver side tower and the power steering pump.

Here's what I'm using for my wait to start /glow plug on indicator and my alternator no charge lights. They're factory except for the glow, but I'm not paying what people want for an amber light so I made my own.

I'm using the factory MBZ pre-glow relay. It took me a second and a few sparks to figure it out, but it works like a champ. Here's where I'm mounting it. I didn't even have to drill any holes. Good karma!
Here's a good link to explain its operation:

Finally, I drilled and tapped the frame plates for the fender supports. I reassembled the whole front clip making sure all the body lines were square and where they were supposed to be, then I marked where to drill. Apparently my dad still has a good eye for body lines because all 8 holes ended up right on top of the old nuts. I studded the bottom to make a rest to ease reassembly. We'll see if that's a good idea or not. While we had everything assembled we clamped down the supports I cut and welded them back on. So they now have the proper 3/8" spacing outboard of where they were.

Oh and what is this guy? It lives near the clutch pedal on the firewall. If it was designed to trap brake fluid it did a helluva job in its former life. I cleaned it up a bit since I was there (glow relay is on the other side).

 

[DPV7070]

Oh, and I made this tee to plumb vacuum to my shutdown valve.

 

[RWBeringer4x4]

Oh and what is this guy? It lives near the clutch pedal on the firewall. If it was designed to trap brake fluid it did a helluva job in its former life. I cleaned it up a bit since I was there (glow relay is on the other side).
View attachment 1091248

I think this is an early emissions computer (or so I've been told). Yours is a 72 so it must have been one of the first years to get it. Mine is still mounted under the dash near the brake pedal on my 75. It has never been hooked up/connected to anything so I can't confirm or deny if the rumors are true!

 

[RWBeringer4x4]

As an aside, I'm totally coveting thy transmission hump.

 

[addicted56]

Looking great and glad to see what you did with the Alternator. I was heading the same direction. I still didn't like the fleabay alternator but after spending an hour or so trying to figure out hot to mount my A/C compressor (still haven't figured out) I didn't want to mess around more with creating another bracket for the alternator. 115 amps is plenty for me as well and if it goes out and is harder to replace ohh well, I will be wishing I had gone with a mechanical fan and then I wouldn't even need a battery or alternator once it got going

I need to go back and look at your oil cooler plumbing. I'm using a different cooler and in the front of the engine but I might do something similar to you and mount it to the side of the radiator support, much more out of the way. Agree on using the stock MBZ GP relay but it seems like there has to be some way to easily shut off the engine using the key. Like the idea you have though.

 

[warpdriv]

I am using this for the fuel shut off.

http://www.mercedesdiesel4x4.com/product_p/a-mb110.htm

 

[DPV7070]

Looking great and glad to see what you did with the Alternator. I was heading the same direction. I still didn't like the fleabay alternator but after spending an hour or so trying to figure out hot to mount my A/C compressor (still haven't figured out) I didn't want to mess around more with creating another bracket for the alternator. 115 amps is plenty for me as well and if it goes out and is harder to replace ohh well, I will be wishing I had gone with a mechanical fan and then I wouldn't even need a battery or alternator once it got going

I need to go back and look at your oil cooler plumbing. I'm using a different cooler and in the front of the engine but I might do something similar to you and mount it to the side of the radiator support, much more out of the way. Agree on using the stock MBZ GP relay but it seems like there has to be some way to easily shut off the engine using the key. Like the idea you have though.

Can you not use the stock MBZ A/C compressor mount? If that's not an option, check out the compressor mount that is found in the G-wagen:

http://bham-jk.com/archive/index.php/t-4096.html

http://s69.photobucket.com/user/Bradl038/media/Auto/IMG_20140309_165001_989.jpg.html

It will definitely complicate the intake, but there's a Hotrod shop near me that's building an OM617A powered G-wagen for an old dude (it's completely bad arse and they're running A/C just like the second link shows. I'm holding on to my factor A/C bracket just incase I ever get a wild hair. It would require serious mods to the oil cooler, however.

Let me know if you need pics of the oil cooler lines, etc.

 

[DPV7070]

So, wiring is kicking my butt. I've got a few items that require 12V switched power and I'm not quit sure of the best way to tap into the ignition circuit. How much extra load can the ignition circuit handle? I don't want to overload it and cause a fire. I suppose I could use relays to pull in 12V from the battery and use a small buss bar. Things that require 12V switched power:

-From the ignition circuit
1. Glow plug relay and light on dash
2. Alternator no charge light, requires 3W bulb in series

-From the headlight switch
1. Boost Gauge backlight
2. Pyro gauge backlight
3. Oil pressure gauge backlight

Also, I've been spending a lot of time tracing wires, but the PO hacked up the harness pretty good. I know I need to bypass the ammeter with at 115A alternator, but I'm kinda lost on where to place the fusible link, etc.

In other news, I put some color on the trans tunnel finally. I'm kinda pissed because a LOT of trash got in it, but what can you expect when painting in your driveway?

 

[DPV7070]

Well wet sanded an had a change of heart on the color. I'm going to re-spray with T-012, Cygnus White, as it's the original color. It probably won't match the exterior very well, but eventually I'm going to repaint the burro.

 

[DPV7070]

Beating a dead horse here, but it's for posterity...Finally completed the trans tunnel. What a royal PITA! Turned out pretty good I think. With the lizard skin, multiple coats of primer, extra steel, and a little fiber fill it weighs about 30lbs! Letting the paint cure inside while we're gone on vacation to FL. Once I get back the fuel tank can go in for the last time and seats can be reinstalled. Yes!


Before:

After:

 

[DPV7070]

Question for electrical guru's.

I've poured over the wiring diagrams that are on @Coolerman 's website for a 6/72 40 series. I've read @bj40green write up on fusible links, alternators, etc. I'm just thrown off since some of the diagrams show a fusible link coming off the battery and one (the cleaned up 1971 diagram) does not. The 1971 diagram most closely matches my harness wire colors, locations, etc.

Current plans are to run the charge wire off the alternator to the (+) stud of the starter, then from there to the battery. (I'm using the starter as the main distribution point).

Background:
- I'm now running a Bosch AL129X 115A, internally regulated alternator. From what I can tell it's NOT a voltage sensing setup
- I've bypassed the ammeter as it wouldn't handle the new alternator. Wires were crimped, soldered, wrapped, and heat shrinked.
- The PO completely hacked up the wiring harness for a SBC conversion, so it's pretty hard to figure out what they were trying to accomplish but I have tied back most of the things I don't need anymore: coil, external voltage regulator, etc.

Victories:
- I have the glow plug relay roughed in and it works as intended via key on/ IGN on
- I can crank the engine with the key
- I fixed about 50 crappy PO wire splices made via twisting wires together and using electrical tape. All joints were soldered, taped, then wrapped with heat shrink.

Questions:
- The WL (White/Blue - formerly negative side of the ammeter) is currently not going anywhere. Should I tie it back in / complete the circuit via a fusible link to the (+) stud on the starter? Do I even need this leg of the circuit? The fuse block is being fed already from where the WL and W join that's in the harness somewhere.

- Should I be concerned that I added a 12V 3W lightbulb to the IGN circuit (the glow plug relay energizes the light when during pre-glow)? I need to add another 12V 3W to that circuit for the alternator idiot light. Is this too much? I guess I could use one of the extra circuits on the fuse block.

Tranny hump and fuel tank have been installed hopefully for the last time... feels good.

 

[DPV7070]

Anyone, Bueller...Bueller

 

[davegonz]

So, you're asking if you need to run the idiot light off of a new circuit or piggyback on the existing one? 3 Watts at 12 Vdc only pulls .25amps (I=P/V). I think you'll be OK if you just add it to an existing circuit.