5ton life span ?

[Mack Attack]

I know these truck will 30-50yrs just fine, I was more wondering at about which mileage are these rigs considered worn out ? Can you crank them up to 450-900K miles like the over the road trucks of the same vintage ?

 

[Mack Attack]

Oops that should say "450-900K" my mistake.

 

[swbradley1]

I don't know if an 800 or 900 series would hold up that long but I'll but a 915 would.

 

[Ferroequinologist]

Give me a few more years and I'll let you know on a XM818...

I would imagine my trailriding is the equivilant of 10k miles of driving, so I'm already pretty close!

Relatively speaking.

They are like anything else. Parts will fail and components will have to be replaced.

Ever hear "this is my Great-Grandfathers Ax. The handles been replaced 3 times and the head twice"

 

[Mack Attack]

I have driven many and several civvy trucks powered by the same Mack and Cummins diesels used in the M50/800/900 series Mil-spec 6by's. all of which logged on several 100 thousand miles easily. so i was just wondering if theres was a magic odo number to avioded ?

As for the axe i get the idea, my great grand dad's would be well into his 100's as im 70 !

 

[Ferroequinologist]

I'm sure with regular maintenance, proper operation and care, they could last that long, or longer.

Everything wears out eventually though. Problem with long life is lots of people like to run at or close to redline in 5tons, and deuces. I've put 22k miles on my M109 and the only issue I have had is the transfer case slips out of high, and I just started to get an oil leak from my front valve cover gasket. It is on it's third alternator.

My truck messed up on Wed, so did Angie's jeep. We were supposed to go to VA for Thanksgiving. Guess what? put the M105 with some barrels of fuel behind her, and drove 'old reliable' the 900 mile round trip to VA. Cruised along at 2300rpm which is 55mph in that truck (G177's)

Where I was going with the ax comment, is you are hard pressed, to pick up a truck, and drive it 500k, and have all the same parts and even whole major components on it when you got done. Unless you took anything that broke off and rebuilt it, and even then, the parts you replaced aren't the same it left the factory with.

We don't really know, as the mil hardly ever let a truck get near that kind of milage without rebuilding it. As SWBradley said, I've seen M915s with over 100k, I seem to recall one at 223k on GL but again, the Army likes to send stuff in for rebuild all the time. I know that my M915 with 101k when I got it has had a different motor installed in its life.

 

[EMD567]

I think the high rpm's are the only drawback to long life for a 5 ton. I see no reason why a 5 ton chassis can't go 500k miles. The only two weak links are the dogbones and the rubber boots up front. The motor will need rebuilding before the a regular class 8 truck, that only because of the high rpms being turned.

 

[Mack Attack]

Ok so when looking at trucks there really isn't i magic "odo number" to avoid, they have just seem to be awful young in mileage and yet they've been rebuilt or replace major units. engein/trans/t-case ect. starters and alts wasn't really the types of things i was worried about.

If i bought a pile of parts rebuilt or replaced everything basically started at 0 miles is most likely what i will end up doing. So i shouldn't expect regular semi tractor life spans from a 6by as the higher rpm/mph ratio ?

The m915/a1/a2 . . . ect is more or less a semi tractor. i was more concerned with the M52/818/916/932 trucks.

I am an AM General, Mack, and REO truck addict.

 

[Ferroequinologist]

M915 and M915a1 is a AM General product! lol

Like EMD said, I'm sure the axles and such would give many many miles of trouble free service if taken care of. Same goes with driveline components.

 

[Mack Attack]

The M915/a1 also aren't 6by's the 916/920-a1 are 6by If the front wheels don't drive I screwed !

 

[wreckerman893]

As a rule a most big diesel engines are just getting broken in at 100,000 miles.......I have seen OTR trucks hit 500,000 with no major issues but they were maintained with due dillegence.

The worse thing for a vehicle (IMHO) is for it to sit unused for long periods of time...seals dry out, critters can get into the wiring, fuel systems gunk up. Unfortunantly military vehicles do a lot of sitting....even more when they enter the surplus system.

One reason you don't see real high milage on military equipment is that a lot of vehicles undergo periodic rebuilds whether they need it or not. I have bought 20 year old trucks with less than a thousand miles on them.

Another reason for low milage is what type of unit the vehicle was assigned to. A M915 in a transportation unit will log more miles than one in a admin unit that used it to pull a van trailer to the field a couple of times a year.

For vehicles it the luck of the draw as to how many miles they will rack up over their life of service.

 

[Mack Attack]

I worked for AM General so I built several mil-spec trucks, I grew up in a farming family that loved Mack, GMC, and REO trucks. Most of which were several decades old when retired. I just remember picking up a M52a1 with only about 30K miles and the Mack diesel was so worn it wouldn't start ! Yet the ENDT-673 that towed it home in a B61 Mack had 385 thousand miles on it running like a champ. I know as I brought to the farm myself. I believe the truck I drove had 6.38 gears spun about 55mph@2250rpm. So it was a rev'r too, I was just curious as why the low mileage trucks but frequent tear downs would explain that and so would sitting for long periods.

 

[Mack Attack]

My concern is I will end up restoring a rig then 5yrs later its all worn out. Is what I find a bit trouble some, I know once get an M52a1 I am going to drive it and drive it a lot. Maybe my updated Mack 6by plan I always wanted to do would be a better choice of attack ? Mack-350/7spd/12R24.5s improve the RPM/MPH ratio.