Four doors, six 52's, and 855 cubes. Monster tow rig build.

[Tacoma747]

Couple years ago I bought a deuce, then a 5 ton, then more 5-tons, and have bought/sold plenty more since then. Have had 10+ 5-tons (still have two running 5 tons), 3 deuces, a M915 (14 ton) and I currently have two 20 tons. This is the build up of one of the 20 tons, this is pretty much the one truck I've had that I want to keep, it is no comparison between it and a 5-ton, it literally does not care about anything I have even towed behind it. A friend with his 5-ton (8.3 cummins) can't keep up with it, even when I was towing about 20k lbs and he was only towing about 3k.

So anyways, here are the specs:

1970 AM General M920
855ci NTC 400 Cummins turbodiesel
16 forward/2 reverse air-shifter Caterpillar 7155 transmission (no clutch pedal, it's kind of weird)
single speed transfer case
2wd/6wd
Detroit lockers in rear axles
I installed 16r20 tires on HEMTT wheels, this increased the road speed, it will run a little over 70mph on the floor, cruises nicely at about 60-65
Fuel mileage, well, I don't think I want to know. If I had to guess it would be 3-5mpg.

I removed the drop axle shortly after I got it, I didn't need two extra tires as I would never be hauling 60K lbs ON the truck (rated to tow 125k I think with 60k on the 5th wheel).

This is pretty much what it started as:
(after I installed 52's, A/C, headlights, and removed 5th wheel stuff)

Then I added a big box, was going to make it an 'RV', but the box was too complicated, it leaked, and just wasn't a good base. Plus I sold my 5-ton wrecker with intentions on making the M920 a wrecker (more on that later).

 

[Tacoma747]

After I sold the big box, I put a deuce bed on it as a temporary bed. I also bought a sweet military trailer that matches the truck perfectly. The trailer is capable of hauling 20k lbs payload.

Now for the fun part. I bought 2 BRAND NEW Freightliner cabs assemblies (Hood included), they are VERY nice, A/C, air ride seats, heated mirrors (one had POWER mirrors), the works. Basically a civilian cab with military paint/additions.

After they sat here a few months while I got up the nerve, I finally started cutting. I have sold a few parts (including one of the hoods) off them for pretty much enough to pay for the cabs.

 

[Tacoma747]

And that brings me to today. As you can see, the rear seats will have PLENTY of legroom! I figured I'd make it as long as was easily possible, as I'd rather have too much room than not enough.

The two cabs will be bolted together with factory holes here, I will also be running a piece of square tubing underneath the rail of each cab to tie them together and make sure they are both perfectly flat (or on the same plane as the other cab I guess).

 

[Croatan_Kid]

Oooh. Interested to see where this goes!

 

[Tacoma747]

It is ready for sheetmetal. I'll be going to get a sheet or two of aluminum on Monday and start on that.

I used rivets that match the OEM rivets, luckily my dad had the tool to 'buck' them since he used to be an aircraft mechanic. There will be some that I can't get to the backside of that I will have to use pop rivets, going to try and find the 'correct' looking pop rivets tomorrow afternoon. The driver side panel is installed except for a few that will be pop rivets. Passenger side panel is cut (lower panel is installed), will finish installed the upper panel tomorrow. I am also putting 3M VHB tape behind the panels to help seal out the elements.

 

[Tacoma747]

Added 7-17

Well the passenger side is great. The driver side was always a 'little' off, but when it came time to put the roof on it looks WAY off and I just can't deal with it. I kept telling myself "ahh, it will be 12 feet in the air", but I have decided this saying applies: "Any job big or small, do it twice or not at all!"

I am going to TRY to drill out some rivets, spread it apart, and hopefully be able to use the existing panel. It might not fit as well but that will be much harder to notice than a big dip in the roof.

The roof panel is .063, I put a slight bend every 1/2" with the brake, as getting them rolled would have required the roof be two panels, and would have cost me $125 per side. I have a metal brake so that was free and I was able to make it one piece. Turned out perfect.

 

[Tacoma747]

Roof panel ready for installation:

A final roof assembly uh-oh!

But it laid down fine in the end, had to hammer a couple spots. As you can see there is a mess of seam sealer, once it dries I'll sand it off.

We (thanks @CasterTroy) were able to drill some of the rivets out of the driver side panel and jack the cab up some in the center, that took some of the 'dip' out of the roof. It is still slightly low but WAY better than it was and I don't think it is very noticeable (I don't think anyone that didn't know it was low would notice).

Anyways, the roof is ON. I have to install some more bracing, as well as an overhead 'console' that will double as a spot for a TV screen for the backseat passengers, but it's main purpose will be to ad support to the roof and sides of the cab.

 

[Bhudgins]

Subscribed

 

[Mac5005]

This is awesome. Subscribed.

 

[offroad cowboy]

Subscribed

 

[frankenyoter]

Yup. Subscribed too.

 

[Tacoma747]

Got them welded together (the pictures in the 2nd post) only to unbolt them from each other in preparation for adding reinforcement under the rails to tie the two frames together more rigidly. I've been doing other little stuff, took out the rear seats, floormats, and peeling off the double sided tape that was behind many of the body panels. New roll of tape will be here Monday, the cabs will be bolted together for the final time hopefully sometime on Monday. Then it will be time to start on the bracing between the upper body.

 

[Tacoma747]

Fresh picture in post #5.

Here is a little inspiration. This is one of the VERY rare M916's that the Navy had built, from what I have found there were 16-18 built. Two sold at auction a few years back, brought over $50k each. As you can see mine will be about 15-18" longer cab. How's THAT for a big boat?

 

[f i s h]

In! Loving this build, completely unique!

 

[rodney eppes]

I like your Military front end, or as it used to be called, "constructor model", Way better, than the Civilian Fiberglass, on the Navy rig!
You've got a Lot of work there, couldn't you have bought a factory 4 door cab? Or is your's somehow different [longer]?
Keep the pics coming!

 

[RobMcBee]

DAAMN! 'scribed!

 

[Tacoma747]

As crazy as it sounds, buying a used factory 4 door cab would have been much more expensive than buying two brand new cabs, selling off parts, and building my own.

I like the am general frontend much better too, but the flip forward hood will be nice for working on the engine.

 

[Tacoma747]

And rodney, yes, my cab is about 15-20" longer than a regular crew cab.

 

[Baker]

i'm in the navy and work at Special boat team 20 in virginia and we have the exact same truck you posted pictures of. It was pulling a mark V in your pictures, they phased those boats out (no longer in service) but we still have the truck and trailer. Cool build though.

 

[Tacoma747]

Those trucks have the Detroit 60 series with Allison transmission (4 speed) with 2-speed transfer case. My truck is a NTC400 Cummins, Cat 16 speed (2 reverse), with single speed transfer case. I wish I had the cummins with 7-speed Allison, those are pretty rare.

 

[RobMcBee]

i'm in the navy and work at Special boat team 20 in virginia and we have the exact same truck you posted pictures of. It was pulling a mark V in your pictures, they phased those boats out (no longer in service) but we still have the truck and trailer. Cool build though.

Lol.... Wonder if you can buy one of those decommissioned.... Imagine cruising around the lake on that ....

 

[Baker]

The only one left is up on blocks as a monument at my command.

 

[justjeepin86]

Where are you working out of now, Michael?

 

[Tacoma747]

Doing this in my dad's garage, somehow I talked him into letting me do it there. Once the time comes to sit it on the truck that will be an outside job though. Ughh....

 

[BrianGreen]

16 forward/2 reverse air-shifter Caterpillar 7155 transmission (no clutch pedal, it's kind of weird)

You should have seen me the first time I had to drive one. My rig got borrowed for a mission and I got a last minute haul mission. 8:00 in the evening, I had to "borrow" one from another company. Nobody was there, I had a key (BTW, the 915/920s were keyed the same), and I needed a truck. It took me about a half mile to get the hang of it.

I still have my 916 and 915/920 keys, so ya better watch out unless you have changed the cylinder. I might need to "borrow" it.