I finished running the vacuum lines today. I used a vacuum tank that I salvaged from a '71 F600 U-Haul truck that I parted out. I mounted the tank inside the right frame rail behind the running board. It is about 7" OD x 24" long. My vacuum connections are all vacuum tight when I have the axle in high gear. When the axle is in low gear, I am leaking thru the shift valve and the vacuum pump will only keep about 10" of vacuum at an idle. In high it will hold around 22" and will hold that with the engine shut off. There is no rubber seat in the shifting valve for low gear, only a metal to metal fit of a plunger in the valve body. I peened the plunger and recut it in the lathe to a closer fit, but I think there may be some wear in the valve body. I will probably have to hone the valve body and make a new plunger. Good news is that the axle shifted beautifully! It split shifted really smooth and I believe the closer gears will work better for the diesel. I didn't get any pics today, I will try to post some tomorrow afternoon.
Thanks, Mark

 

Here is a photo of the vacuum line routing on the firewall. I used 1/2" OD copper. I wanted to use 1/2" plated steel, but I couldn't get any locally. I will probably go back and add a couple more straps to secure it better to the firewall.

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This is a photo of the vacuum tank. It is bolted to the inside of the frame rail between the transmission crossmember and the Brownie front crossmember. Sorry for the poor photo. I should have taken it yesterday while I had the truck over the pit.

I still need to install new u-joints in the front driveshaft and paint both of them.
Thanks, Mark

 

Mark,

All your work looks real nice. I am sure it was fun to try out that new axle.

Side note: Is that front yoke missing the dust cap/seal on the splined end?

Nelson

 

Very nice job with the copper tubing. I'm doing the same with some of my steel tubing because it's pretty beat up. I polished and sealed it where it's visible. Aren't you missing a few hose clamps?

 

Hi Nelson, Thanks for the kind words. I was wondering if someone would comment on the missing dust cap I want to replace both u-joints and paint the drive shaft. I will order a new dust cap and seal when I order the u-joints. I haven't decided what I want to do with the rear drive shaft yet. I made a new drive shaft with the 1410 joint at the rear for the axle. The slip yoke from my old drive shaft fit the new splined shaft I used and has a 1350 joint in it. I have a couple more new 1410 joints and a 4 bolt 1410 flange yoke that fits the companion flange on the Brownie. I would just need to order a 1410 slip yoke when I order the front shaft joints. It works fine the way that it is, but with all the gears I have, I wonder if I shouldn't go ahead and change to a 1410 joint on the rear shaft. Decisions, decisions
Mark

 

Bob, Thank you for the kind words, I didn't have any of the steel tubing. The fire truck that I bought for the two speed axle, had the shifting valve and all the tubing removed for some reason. They had also removed the diaphragm and locked the axle in low with a piece of angle iron. I used 1/2" PEX to run down the frame to the axle with the PEX fittings. The hose is 15/32" Gates vacuum hose. It was really a tight fit on the 1/2" copper and I don't have any leaks now, but will probably go ahead and add hose clamps to all the connections.
Mark

 

I went ahead and installed the Mercedes Benz powered emblems on the hood.

I think they look fine there.
Mark

 

I think they are uber cool and appropriate. Understated elegance.

 

Thanks Bob! I saw a pair on the doors of a Freightliner, so I just had to order them.
Mark

 

Slick build mark!

 

Thank you!
Mark

 

Mark,

Those Mercedes emblems looked like they were installed from the factory. Looks real nice.

Nelson

 

Thanks! Nelson
Mark

 

I built a mock dash and firewall so I could build a wiring harness. Hopefully I can leave most of the components on the harness when I remove them from the mock dash and install them in the truck prewired.


I bought a NOS fuse panel at Petit Jean swap meet a few years ago. It is the under hood fuse panel for an early 2000s Chevy Tahoe and pickup. I paid $25.00 for the panel and it had all the fuses and relays in it.


I bought the green, red, grey and black terminal blocks at a salvage yard to retain the terminals and also so I would know what type of terminal the panel used. I also got the cover from the salvage yard to get an idea what each of the fuses and relays were originally used for. It helped me to decide how I wanted to lay it out.


The wiring from the back side of the dash. I still have a few more wires to run, then I will tie everything up neatly. I am thinking of using wire ties under the dash instead of taping everything. I will tape everything out side the cab.


Wires coming thru the firewall hole to the front and rear of the truck.
I am enjoying the process of building the harness, but it would have been cheaper in the long run to buy a harness and fuse panel prewired.
Thanks, Mark

 

Instead of using zip ties or tape why not just use asphalt wire loom and cloth tape ? . You can split the loom for under dash where you have stuff already terminated and paired with cloth tape it would look quite period. Just a suggestion.