M1078 GVWR Over the Road

[504]

Hello,

I did try searching this, I'm sure this has been asked before but I wasn't able to find the threads, my apologies.


Is there a GVWR on an M1078 for "civilian" or over the road usage? The truck is clearly able to hold more than 2.5 tons payload, but the GVWR doesn't indicate that at all.

Any help would be greatly appreciated.

Thank you

Mike

 

[NDT]

Welcome. The LMTV's single rear Meritor RF611 axle is rated at 15,000 lbs. The tires are good for 10,000 ea. So figure the truck weighs 18,000 empty, say 8000 of that is on the rear, so leaves you with 7000 payload, or 3.5 tons. Most prior military vehicles were rated at twice the capacity on-highway as cross country, but with the FMTVs this is not the case. The data plate makes no mention of this.


Now of course a search here will tell you that owners have put WAY MORE than 3.5 tons in their trucks.

 

[Vaquero]

I would add a comment to the tire capacity, NDT is correct, the tires do have a capacity of 10,000 pounds each but only if they are inflated to 100 psi. I’m fairly certain the CTIS only inflates the tires to a maximum pressure of 55 psi for highway driving and I’m not sure how it would handle the higher pressure if it were added externally. I’m also not sure how the axle seals would handle the pressure as well...
Does anyone have any experience with higher tire pressures?

 

[coachgeo]

I would add a comment to the tire capacity, NDT is correct, the tires do have a capacity of 10,000 pounds each but only if they are inflated to 100 psi. I’m fairly certain the CTIS only inflates the tires to a maximum pressure of 55 psi for highway driving and I’m not sure how it would handle the higher pressure if it were added externally. I’m also not sure how the axle seals would handle the pressure as well...
Does anyone have any experience with higher tire pressures?

The citis for (some? all?) the MTV variant (6x6) is 80lb highway using same tire and wheel. Different controller programming. Don't recall if any other valves in ctis system is different between LMTV and MTV.

 

[DiverDarrell]

4.5 tons, I do not recommend this. I drove 5 miles max speed of 35 with this and you can feel the cog. FWIW Michelin on the rear 12300lb capacity at 100psi. Horses will be happy with their dry paddock

 

[mkcoen]

I regularly ran mine at 80 psi. Of course I had the CTIS unplugged when running at those pressures but had no issues with the tires.

 

[Green Mountain Boys]

I think you would find that law enforcement (and lawyers) would only be concerned about the GVWR stamped on the truck. I would not want to be in a position to have to argue that the truck is safe to drive at a weight greater than what is stamped on the truck. So if your concern is about what is legal I would stick with what is stamped on the truck.

 

[aleigh]

It's a reasonable question, since older military equipment sometimes listed different GVWR ratings based on on or off-road use. The M1078 only lists one weight, and we know that use is off-road, so it's logical to conclude that there is a higher on-road capacity than what has been stated. Which also seems to be self-evident when you look at the design of the truck.

I don't think enforcement is going to care about GVWR beyond making sure your registration is valid (ours is declared weight in AZ), but they will care a lot about the GAWR. The data plate for the M1078 lists them as 12k front and 10k back. There is an obvious discrepancy though because as has been pointed out the manufacturer rates the axles higher. But of course there are other aspects that go into a weight rating, like brakes, suspension, etc

This is just my pet theory but maybe they de-rated the truck to make FMVSS (isn't there a brake distance test at gross) which was a contract requirement. In other words, rating the truck at the off-road capacity (which was also the contract requirement I'll assume) made it easier to past the performance tests, if the contract never stated it needed a higher over-the-road capacity.

 

[Vaquero]

It’s been my experience in MT that if you are under 26,000 GVW, and your vehicle is not under a commercial license, then the DOT has minimal or no authority to inspect or fine you (other than dipping your tank). However, if you exceed any of the recommended capacities (GVW, tire rating, etc.) and have an accident, I’m guessing you would be at fault and attorneys would eat your lunch.
If the truck were to be utilized for commercial use and you were inspected by the DOT, hang on to your ass if you are not up to speed with regulations and weight capacities. The DOT here would first look at the GVW you paid for on the registration, then the capacity chart on the door, then the capacity on the tires and go from there. I’m confident that because the truck is so unique, they would go over it with a fine tooth comb and those boys can find things wrong on brand new trucks if they want.

 

[Awesomeness]

so it's logical to conclude that there is a higher on-road capacity than what has been stated.

While it might be wishful thinking, I don't think there is much rationale for it that would be "logical". If it had different capacities, it would have been a benefit for them to say so, and they didn't. Many parts of the truck are certainly overbuilt, but we're not totally sure what the bottleneck components are. The ratings on the tires and axles seem like likely limiting factors, and those numbers would certainly have built in saftey factors which would explain why their are anectdotal stories (such as above) of overloading them without failure.

 

[aleigh]

If you take a passenger car, load it to gross, and drive it down a broken off-road track like a rally car, it'll break, probably sooner rather than later. Different environments, different stresses.

 

[pitrack]

Hey guys, new here trying to learn as much as I can. I was looking at getting a Stewart & Stephenson 5 ton truck to use for landscaping work. I am talking with a company that refurbishes them and paints them etc. The guy I am talking to said that these trucks are stamped with an "on-road" weight rating. He told me the dual axle 5 ton truck has a 48k weight rating. He said there are tags in them with a 48k rating. Is this true?

 

[snowtrac nome]

I think that is the gcwr when using a trailer your not going to put 20 tons on the rear axle set.

 

[Awesomeness]

Hey guys, new here trying to learn as much as I can. I was looking at getting a Stewart & Stephenson 5 ton truck to use for landscaping work. I am talking with a company that refurbishes them and paints them etc. The guy I am talking to said that these trucks are stamped with an "on-road" weight rating. He told me the dual axle 5 ton truck has a 48k weight rating. He said there are tags in them with a 48k rating. Is this true?

Not true. The second post in this thread shows you how to calculate the answer. Not anywhere close to 48k.

 

[snowtrac nome]

I think the tractors were rated at 44k gross but that is with a trailer. that's not total weight on the cargo bed first off an mtv would never bridge 44 k between 3 axles on such a short wheel base. I will admit they are over built I had a trailer with a d3 behind my lmtv that was close to 35k between 4 axle trailer and dozer I was not on a dot maintained road the truck pulled it well and had no problem stopping even though the trailer had no brakes. had I been able to reach 55 it may have been different but road conditions limited me to aboyt 40 max.

 

[pitrack]

I was having a hard time believing him, maybe I’ll ask for proof and see what he says. Any truck you’d recommend that could haul 10-12 tons payload?

Thanks for the help

 

[topo]

In New Mexico goes by how wide the tire is at 600 pounds per inch .

Max single axle weight is 21600 pounds
Max tandem axle with 4 foot spread is 34320 pounds


With 1100-20 tire on a single axle max weight is 13200 each tire is rated for 6600pounds
With 900-20 tire on a single axle max weight is 10800 each tire is rated for 5400 pounds


My military tires in 1100-20 are rated at 5400 pounds per tire
My military tires in 900-20 are rated at 4000 pounds per tire

 

[Vaquero]

I’m always a little confused when looking at the payload specs for the S&S trucks. They always show the same payload capacity for the same truck irreguardless of how it is set up. For example, a M1078 with a winch, pto, and hydraulic tank should have a smaller payload capacity than the same M1078 without but both are listed as being able to carry 5000 pounds.
I resolved this by looking up the specs for the Meritor axles and found the front axle has a capacity of 14,700 pounds and the rear has a capacity of 15,000 pounds for a total 29,700 pounds. The tires are rated at 10,000 pounds each totaling 40,000 pounds. The springs are still an unknown that I’m still working on. Obviously, the truck’s GVW will be limited by the component with the smallest capacity. This same logic might apply to the truck you’re interested in as well.

 

[Stevekelley]

Hello,

I did try searching this, I'm sure this has been asked before but I wasn't able to find the threads, my apologies.


Is there a GVWR on an M1078 for "civilian" or over the road usage? The truck is clearly able to hold more than 2.5 tons payload, but the GVWR doesn't indicate that at all.

Any help would be greatly appreciated.

Thank you

Mike

The GVWR for the M1078 is 22,770 lbs
The actual weight of the truck stock is 17,214 lbs
This means you can legally carry 5,556 lbs of weight.
yes it will carry more but it is not designed to carry more. Carrying more then 5,556 lbs could be dangerous and/or damage the truck. Of course I highly doubt anything would happen if you were a Few hundred lbs over but DOT Wouldn’t approve.

 

[aleigh]

For whatever it's worth, mine scales out at about 16,800. I can't remember if that's with or without the cargo cover on. I don't have a winch. With me in it.