M915 Road March - 650 miles

[NDT]

Lots of you are getting interested in these trucks so I figured I would post on my recent trip to Red River Depot to pick up a M871 trailer from GL. The good: The truck, one from the Illinois National Guard, ran flawlessly the entire trip. She runs best at 55 mph, that equates to 2000 RPMs on the big Cummins which is a safe speed. Got 6 mpg. The bad: The ride!! Both bobtail and with the 15,000 lb trailer, you are beat to death on anything but smooth asphalt. The Hendrickson walking beam suspension is to blame. I would have to slow to 40 mph just to maintain control. Also, the engine is plently noisy, but I will reserve judgement on that as I have not put the muffler stack back on. Sorry just one pic, it was pouring rain the entire time. Also, just a little disappointed in the power. I was expecting 55 mph uphills with the empty trailer, but that was not to be. I think some injector work may be in order, as other commercial rigs with equal HP were blowing by me. But with the Allison, it was a different matter at stoplights! The truck will accelerate along with car traffic easily.

Now my big question is to paint the truck to match the trailer, or visa versa?

 

[M1075]

Nice pic. I vote for 3 color Camo on the trailer.

 

[M813A1]

Hi James ! Nice looking truck and trailer !! Is that one of those trailers from Hooks ?? That tractor should pull I use to see that combination all the time at annual training in Ft Stewart Ga.

 

[NDT]

Yup it is a Hooks trailer. A bit of a disappointment, but you get what you get when you do not preview. Trailer looked like a sand painted version of the rebuilt M871's at Ft Polk, one like Trailboss got. NOT. It is a quicky repaint over rust and flaky paint with new tires, new sideboards and new lights.

 

[gunboy1656]

Since it was a paint job over rust, I say strip and repaint the trailer. Since it will need the maintenance anyway. The truck still looks like a good coat of paint on it.

 

[reb87]

Power you should have. Mine will accelerate up hills with 35000 lbs(truck and trailer). It loses very little with 85000lbs. Been hauling corn out of muddy fields with the m919 WOW!!. I had a power problem with my m919 and it ended up being a little filter ontop of the afc valve. The filter had a one way valve that looked like it was put together wrong. I hooked up air compressor air to the afc and regulated about 40psi to it and had power until I blew the gaskets out of the IP. I got a new pump and then discovered the filter problem when I had no power. I fixed the filter and now I have amazing power.(insert toolman grunt here.)

 

[BKubu]

Does the M915 have the 5 speed Allison or the 16 speed semi-automatic CAT transmission? That may make a difference. I believe the M915A1s had the Allison transmission.

 

[wreckerman893]

When we convoyed from Fort Benning, GA., to NTC in CA in 915's with the Cat Tranny we were keeping up with (and in some cases blowing the doors off) commerical rigs. We had turned the Cummins up to 2300 RPM and were carrying moderate loads (three axle trailer with 2 deuces on each trailer).
You probably need to find a good old fashioned diesel doctor (one well versed in mechanical pump engines) and have him tune her up.
She should do a lot better than that.
The ride is never going to improve much...the wheel base is too short and without air ride you are going to feel every bump. I already have a set of Freightliner air ride seats to go in mine.
I have connections to a large truck junk yard and if I hit the lottery I will be stretching the frame and installing air ride. Maybe adding a sleeper too.
By the way...I need a drivers side hood latch and an air horn if anyone has a parts truck with said items on it.

 

[NDT]

Does the M915 have the 5 speed Allison or the 16 speed semi-automatic CAT transmission? That may make a difference. I believe the M915A1s had the Allison transmission.

The slick has the Cat, the A1 has the non-overdrive? Allison. armyman30years (RIP) wrote in several threads here that the Cat trans trucks could do 100 mph with the governor turned up. That's a little fast for me . . .

 

[Monty]

Definatly do the three color on the trailer.

Looks good, I just picked up an 818, if I can get enough use out of it I've got my sites set on a 915.

Congrats on the score.

 

[Artillerydan]

OK I have been wanting to go down this path M915 M916 for years now.... But no trucks. Now they are comming out. I did not know there were two transmissions? OK now that a few of you have play time and actual military time behind these boys, whats the best one for over the road speed and pulling power. M915...M915A1...M916... M916A1... Wanted to go with the M916 to put the larger michelen tires on it but will they fit under the M915 with no lift. Getting close on this so Info is MUCH apreciated..

 

[wreckerman893]

Dan....I just got mine repaired (air tank was FUBAR) and on the road. It has the Allison in it and I have not pulled a load yet.
The 915's/916's I drove in the Army had the Cats in them...they ran like raped apes.
The downside with the Cats is that they are an oddball tranny that had very little civy application...the chance of finding a Cat mech that is well versed in them is prob slim to none. And anything made by Cat is gonna cost money when it breaks or for routine replacement parts.
If the truck has not been modified (extra air tank added) it will slip into neutral if the air drops below 80 PSI (Cat tranny only). This makes for an interesting ride if you are coming down a steep grade with a heavy load.
The 400 Cummins has plenty of power unless you are grossly overloaded.
I pulled D 8 dozers with our 916 and always had plenty of power.
I am watching an unnamed auction site for a good trailer to pull with it.

 

[reb87]

Dan, I have a m919,m915 and m915a1. I pull a grain trailer with the tractors. The 915a1 is a nice choice for ease of driving. I havent had any problems pulling 90000 lbs with it but today I was in a little bit of a damp field and the truck had settled in just a little. I couldnt get the engine to rev enough to move the truck forward. I went in reverse and it moved fine and then it went forward. If you keep it on the road it works real good but dosent have low enough gears to be totally reliable off road if the ground is soft. I have 11.00x24 tires from my m919 on my m915a1 so I can run 65mph so I lose a little low end power there but going faster makes up for it.

The 915 is a better choice if you need low end power and it also has higher gears for speed. Its only drawback is a lot more shifting and no "drive" position. You have to shift down from 16 to 11 one gear at a time, from 11 down can be shifted two at a time, not supposed to let the engine be under 1100 rpm for more than a few seconds when in gear.

I think the 916 is geared lower like my m919 so you need some tall speed rated tires to go over 60mph


Keep in mind the big single military tires are speed rated at 55 mph so its no good putting them on to gain speed. They are working great on my m919 though, ive had 600 bushels of corn on and been able to bog out of muddy fields with no problems. The truck weighs 66000 lbs with the corn on and I have great traction.

 

[NDT]

Dan, I'm kinda sure there were only A1 (Allison) versions of the M915. All the 916's and so on that are coming out will have the fussy 16 speed D-7155 Cat trans. I would not put big rubber on a 915A1 because the 1st ratio is not very deep. Big rubber would make this worse. Also the tires will not go under the front fenders it would appear. I would say that which truck you seek out has to do with what you wish to do with it. I did not need 6x6 or winch, I needed a simple highway truck to move running armor on a M172 trailer. For me, either the 915 or 915A1 was perfect. When all the running A1's sold several months ago, I jumped in. The rumored extreme speed capability of the 915 with the 16 speed transmission was tempting, but could also be a death sentence.

 

[Artillerydan]

OK... I opened the box so here goes....
My planed use for the truck would be to lenghten the frame to 20 to 25' behind the cab. Install a custom made RV body (have a friend that does this) and use it to tow a "light" flat bed (via pintel hitch) with my toys on it, Quads, Sand rail etc... also to go to national shows with the smaller MVs on the same trailer. Use number two "heavy" flat bed would be towing the tank on a 5th wheel trailer with a dolly. I currently own the trailer and dolly combination it was a standard combo in WWII, it is a corps of enginers trailer. So I want to be able to do 65 to 75 with the light trailer like any other vehicle on the highway. Thoughts on the heavy load???