Just purchased an M54A1

[Mrgior31513]

Hey fellas, I just completed a long term goal and finally got a 6x6! I was originally going for an M35 with a multi-fuel engine but I couldn't pass on this ride. The tag says 1975, not sure if that is manufacture date or a rebuild date, M54A1 with the Mack ENDT-673. The brakes are out (brake booster) and has extremely questionable tires. Have the brake parts already and got some newer wheels with the 14.00 20R Michelin XZL and a few Goodyear AT-2A treads (some brand new and most like-new) from a buddy, so should be good to go right off the bat with a more aggressive look, beefier tires and a somewhat higher cruising speed.

I know there are probably tons of answers to my questions, but as I am so new to these vehicles and already immersing myself with tons of information about this vehicle, I figured I would ask a few questions and get to know some guys on this forum, as I have already been tearing through your old posts in the last week trying to learn as much as I can about my new truck. I got it for an RV conversion, an off-road vehicle as well as to haul/tow personal stuff, so my work is cut out for me and the designs in my head are going to take some time to work out. I know the M35 would have been a bit more practical for the camping and off-road part, but I couldn't turn it down for the price and condition, a few seals need attention but it looks solid and fires right up. Luckily I am a capable auto-mechanic and a welder/fabricator by trade, so my endeavors will be a lot cheaper than many would be capable of pulling off. I haven't had any experience working on either diesels or big-rigs, so a few new systems to figure out.

I was thinking of just running singles in the back and rotating the tires that I do have for a full 5 spares, unless I have to haul something then perhaps putting duals back on for heavy loads. The wheels are not offset to the degree of the original ones, is there a spacer that I need to get for running duals and should I use a spacer for running singles or should I just wait on funds and have all of the tires switched to the old rims? The wheels look like those of the M900 type.

Before I do any driving on it I am going to do a full maintenance/service on the vehicle and have already downloaded a lot of service and technical manuals for it. Are there any points of main concern that I should be sure to check and/or even just upgrade before I put the vehicle into service? I've already got the remote master cylinder reservoir kit while I was researching the brakes, but I am sure there are several little such upgrades, improvements or weak points that hopefully someone can recommend. Patience is the difficult part, but I have some work to do before I register it and already have to regenerate my pocketbook, so patience isn't much of an issue yet, but I can't wait to show off my new ride a little bit and hit some mild trails to get the feel of it.

 

[Mrgior31513]

Here's some pics of the truck and wheel type.

 

[dmetalmiki]

Welcome to the site, hobby friendships, And the exiting and interesting events to come when you have it all fixed up and ready to show,

Nice, Well done you.

 

[98G]

Those wheels are 939series combat wheels. They can't be dualled, nor is there a reason to want to until you go really really heavy. It's almost certain that you won't go that heavy with a standard 14' cargo bed.

The 14.00R20's won't safely fit on the original lock ring rims.

The Mack version of the M54 is highly desirable. I would be **extremely** reluctant to cut on it or weld anything to it. Trade it for three dueces or two normal 5tons with a multifuel or Cummins NH250.

Your comment about the deuce being a better choice as a camper/offroader is only accurate in the context of the Mack M54A1 being a highly desirable collectible that you wouldn't want to beat on. The M54A1 is generally quite a bit more capable than a deuce....

More Pics!

Edit to add - be sure to deflate the tires and remove the CTIS counterweights before mounting the wheels.

 

[AZDeuce]

Mrgior31513, Conratulations that is a beautiful M54A1 even has the winch, that or s similar M54A2 is my current dream truck, I'm glad for you, you'll enjoy fixing her up and then playing with her on and off-road. I used to run a modified M52A2 out in the desert (w/winch) you'll be amazed at what she can do for you. good luck! - AZ Deuce

 

[pmramsey]

Macks with the ENDT-673 engine were built from 1959 thru 1966. If you have a 1975 dataplate, it is a rebuild. It will have the latest and final mods to the ENDT-673 engine. It turns 220 horsepower. The Spicer direct-drive transmissions were upgraded to five-speed with overdrive. The steering system was upgraded to the superior system used on the newer M809 series 5-ton trucks of the 70s and 80s.

The ENDT-673 engine performs best on the 15-40 semi-synthetic oil. It requires additional additives. Check out the cooling system in detail especially for rust in the system.

This 5-ton runs rings around any 2.5 ton from the same period.

I did a cab off rebuild of my M54A1 five years ago. Details can searched on this site.

 

[Privatewrench]

Nice looking truck, and welcome to the site!

 

[SCM35A2]

Welcome to the site!

 

[fasttruck]

Macks will pull harder than a Continental and out run a NH250 Cummins. Naturally the military got rid of them first.

 

[Mrgior31513]

Well thanks for the replies and info on the truck!

As far as off-road I had heard that the M54's were a lot easier to get stuck with the extra weight, and figured with any kind of load on it that it would especially make less suitable. If that is not the case then I am kind of glad I stumbled into this truck. Thanks for the information on the counterbalances on the wheels and I will be sure to hold on to the original rims and probably slowly put new tires on them just to have the originals.

Thanks for the info on the data plate, I was hoping it wasn't the earlier model Mack engine build that had some issues, and the extra fixes I am sure were major improvements from earlier models. As far as the cooling system, I am planning on changing all of the fluids, full maintenance checks on all systems and fix a few minor seals and drips that I noticed on it. It'll probably take me a few months to go through it and it will likely be a ton of work, but I prefer to know my vehicles systems pretty good, and this one has more than I am used to.

 

[bigmike]

Mrgior21513,

I agree with others that this truck should not be modified in any way. It's a great piece of MV history. This would make a great Vietnam gun truck build.

 

[Mrgior31513]

Well, I am not planning on chopping into it, as the only real modifications I am planning to do is rig it to dual run off of fryer oil and a remote master cylinder reservoir for easier/safer brake fluid check, and the disk brakes seemed like they could be a nice addition for a back up braking system ~but that isn't really anything on my list as of yet. Building a camper for the back of it for an RV conversion, it is not necessary to weld or chop holes into the truck, nor is it something I have been in the habit of doing on vehicle modifications. I prefer to be able to swap my mods easily between another truck if I had to.

If it is that collectable I might just fix the brakes and list it, see what I can get without having more time in checking the thing out. I'll consider any serious offers and trades if someone wants it that bad. I'll get it here and fix the brakes and post some pictures. If the beds and frames are the same between the M54 and M35's then I can use it for a template for everything I want to do anyways. As for what needs attention on the truck: about the only thing I noticed was a cracked passenger side window and the soft cover for the cab needs to be replaced (will make a custom aluminum one if I keep it), and a few slow leaks on a few drain plugs. Would be easy to make a video of a vehicle walk around, fire it up, post it on YouTube.

 

[fasttruck]

Reference post 12: the 5 ton bodies are wider and longer than a deuce. As for getting stuck, both 2.5 and 5 ton trucks stock have 20" wheels so the ground clearance under the differential is close if not the same.

 

[Mrgior31513]

I know one of the things that makes my Toyota much better is being narrower, having a shorter wheel base, and being so light. Having some weight helps with traction to a point, but too much and you tend to dig in to mud etc., so I would guess that the deuce is much better off road.