Builds 1973 Mercedes R107 build (2 Viewers)

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Crap is right, can’t tell you how many of those I replaced for leaking coolant or not moving to “park” position and draining the battery.
 
Crankshaft 32-1 trigger wheel

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Built a trigger sensor bracket. Added a speed hole because speed hole.
Pulled the ignition parts out. Stock ignition had a coil, two ballast resistors, and a large module box.
Got the passenger side inner fenderwell down to bare metal and put a coat of POR-15 down.
Sandblasted and powdercoated the fan and the hood hinges.



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I took the washer pump out to clean and paint the fender well. Took it apart and ran it through the sonic cleaner. The pump shaft was siezed in the shaft. A little PB and some wiggling and it loosened up and was pumping so the rubber diaghram is still good.
Edit: I didn't take the pump apart yesterday because I was worried about the rubber. I had run the motor on the power probe, but not the assembly. When i did the pump was too stiff for the motor to turn it.
I pulled the copper plate off the pump. No diaphragm. It uses brass gears to pump. The idler gear was very stiff. Disassembled and everybody back in the sonic washer. Scrubbed everything with a brass wire brush and sonic washed it again.
Backing plate and the mounting bracket went in the vapor blaster. Then clear powdercoated them.
Brass plate was pitted where the gears had stopped. I blocked it with wet dry paper until the pits were mostly gone. Then polished it.
Cleaned the gears, shafts and bushings. Lubed them with some moly and reassembled.
Works well now.
And the one from the 73.

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Cleaned the overflow and washer bottle. The 78 had a nicer, but still pretty yellow overflow. The washer bottle was new, but looked terrible.

Scrubbed them and soaked overnight in bleach. They're clean, but not great. The 73 bottle slid over formed sheetmetel slots stamped into the forward upright of the overflow mount. I drilled the spot welds and took it off the 73. Sandblasted powdercoated black and mounted to the fender in an existing hole. New cap in the cart at Pelican.

Plumbed it to the pump mounted in the stock for 78 position in the inner fender below the headlight. People reading this thread will prolly be the only ones to ever see that beautiful rebuilt pump

78 overflow mount is spot welded in the front and bolted in the rear. Rear was also unpainted so it still is. Just clear powder. Stock speed hole because the engineers knew Sport-Liecht.

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I went around and around about a single coil with an igniter or 8 smart LS coils on a wasted spark set up.

I went with a GM 8 pin igniter found on small cap HEI cars. (Delphi DS10059) GM HEI coil (AC Delco D573) from the same period. Pigtails all available new.

It seemed easy to put the coil and igniter close to stock locations. After lots of pondering in my pondering chair I ended up using the stock coil and ignition box mounts.

Powdercoated the stock ignition box mount, then ground off where the module would sit. Dielectric grease between the module and mount. Bolted down good and snug since it grounds through the module body. Made a 20g top for it with a little lip to fit around the groove around the plug that stuck out from the GM dizzy. 4 wire plug is wired to 5v vref, cam signal into Speeduino and IGN1 timing control from the Speeduino and cranking bypass for no computer control during cranking. Front 2 wire is 12v ign and cam ground. Rear 2 wire that was in the dizzy goes to the pick up coil.

Last pic is new ignition box next to the old one. Stock ignition box with pigtails might be worth something to somebody.

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Next up is getting under the dash to take the booster and maybe wiper motor out. I'd like to get the inner fenderwell down to clean metal all the way to the firewall.
I need to run PCM and PCM fuse block and relay on the other side under the dash.. The big question is how much dash needs to come out for the HVAC conversion. I'd like to use the 73 dash pod too. Bigger tach, clock in the center hole of the dash and recently refurbished needles. Also, better reflects the engine mileage.

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W107 chassis started like mid 72. Dash structure wise, it reminds me of the W113 (230,250,280SL) and the W114 (250,280) mid size 4 door. They all share in common welded in dash structure from “A” pillar to “A” pillar area that is difficult to work around. On later models that stuff was bolted in and removable. Take lots of phone pictures, it’s not going to be easy.
 
Pulling the booster and wiper motor wasn't bad at all. Everything is accessible enough. I practiced on the 73. Seat was already out as was the lower dash. Taking the instrument pod out helped a lot and was something I wanted to do. All 4 bolts and the pedal pivot bolt were easily accessable.

Probably not switching gauge pods. Plugs are different. Too bad. I'll refurb the 78 while out.

The 78 was about the same. Steering wheel and gauge pod. Lower dash panel. Didn't bother removing the seat. I did have to remove the Ford-Philco cruise control module. Hope it works better than the Chrysler Climate control. In typical Benz fashion it was held by one bolt that also held another module.
GM - our engineers say it needs a minumum of 2 bolts. That's all it gets
Toyota - our engineers say it needs a minimum of 2 bolts. It gets 6.
Mercedes - our engineers say it needs 2 bolts. We will find a complex way to make it only use one bolt that also does 3 other jobs. It will require three special tools and several steps in the correct order to remove. You will follow the steps!


The cast aluminum pedal hanger/switch mount/firewall brace is similar engineering. Elegant and something Ford would have made from stamped steel for pennies.

wiper motor bolts were easy as was the linkage pivot bolt.

The area under the booster and wiper needed attention. Fortunately, what looked like crusty, flaking rust was just seam sealer. The rust is treatable.

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So, the reason the fenderwell had to be stripped down and re-painted was to mount the coil and ignitor. The ignitor is down low on the mount I modified the other day. I made a bracket for the coil and mounted it up.

Cleaned up and painted the booster. Cleaned the brake reservoir in the sonic cleaner.

Posted a couple of wiring diagrams stolen from GIS.

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More buttoning up. Brake calipers on and all plumbed. Radiator in and filled. I left the shroud and fan off for now, I'd like to be able to get to the crank sensor to adjust it. Moved the vacuum solenoids from the 73.

Decided to put the cowl in sealer instead of POR-15. If I'm going to mask to spray I might as well do all the way to the windshield. Where the cowl vent grills were it had been painted black, then oversprayed with red. When I was stripping the paint there was yellow under the black. I don't know if it was painted black at the factory after the whole car was sprayed, or if someone did it later. I like the look, so I did the satin black. I'm regretting not doing the firewall insulation, but it'll motivate me to do the engine bay when I do the color change.

Pulled the front end down. No rust behind the headlight buckets.

Investigated the driver fender. The red was lifting and there was a chunk of filler missing. The car was so rust free everywhere it didn't make sense it was a rust repair. Looks like it got hit right on the rubber trim. There's a row of screw holes from a slide hammer, and then they hammered on a lot of filler. I'm going to pull the fender from the 73 that appears to be good. That'll give me an idea if I want to pull the damaged one or try to fix it in place. Even if I can just get behind it with a dolly it should be an easy fix. The weird thing is the repair was behind the yellow. Someone fixed the yellow car before it was painted red the first time.

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Painted needles and polished the plastic. Replaced the bulbs with LED.

50 year old German wiring diagrams suck, but I think I've got it figured out.

Most of yesterday was spent finishing the Speeduino harness and loading the firmware. Built maps for VE and fuel today.

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Pulled the fender on the 73. It's been replaced. Probably aftermarket but the bumper bracket i need still has the MB parts sticker on it. It's a solid back up if I can't fix the stock one. The 78 is bonded on the top lip. It'll require heat and patience.
Speeduino is all hooked up except for the wide band sensor being installed in the pipe.
Dash is back together. It looks like the dash was originally moss green. Same with the seats. So maybe this car was ordered in Mimosa yellow with an avacado green interior.
 
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Got started on stripping the hood and ds fender. Bundled up and did it outside. 35 and no snow in Jan is pretty OK. The fender was bonded on the top edge as i expected, but the previous repair included a metric crapton of undercoating. That fender weighs many times more than the 73. The undercoating is an inch thick in some areas.
The more I cleaned off the 78 fender, the more damage I found, so it's going in the "fix later" pile. stripping the undercoat alone is a major job for future Gum. The aftermarket one from the 73 is going on. Stripping that found some minor surface rust spots from not sealing the e-coat. Hopefully, sealer on several parts today if I can make room in the shop. I'd like to have the hood back on soon.
There was a crease in the 73 fender and I thought I should bash it out. Crease came out pretty easily, but shrinking the stretched metal took a while. I welded the antenna hole up. The 78 is in the rear.

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Went to put the bumper back on. Couple of hours later it's down to its component pieces and I'm trying to plan out how to make some patches. The left side is all new, like the fender. The right side needs a patch in the main frame structure and a channel that I cut off. The channel holds the rubber insert. Neat engineering the way it all holds itself together. Less neat is the way is all traps water and crap.
Inside of the right side chrome needs cleaning, treating and coating.

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