Singleing Out M Series Vehicles

[1943ht]

Installing a turbo in my M818 this week in anticipation of singleing her out in the near future (All ready have my new tires - Goodyears and wheels) .. A retired Marine Corp Buddy of mine with 30+ years of service as a Maintenance Chief is totally against the concept for that series vehicle .. here are just a couple of issues he brought to my attention .. Thoughts, comments experience with these issues would be appreciated ..


MarCor went to super singles on M818’s and some other MV’s and switched back – Reason – Vehicles couldn’t handle rated loads and at times “laid over” the tire creating a dangerous control problem. Later, they got Goodyear to fix the problem with some kind of change in specs.

They’ll make 900 Series MV’s go faster (70+) MPH, but on 800 Series the gearing won’t allow it, but transmission check cycles will have to be increased because the trannies will be running harder and wear out faster?

Super singles are non-performers in snow and ice conditions,

 

[papabear]

Well Sir...I don't have all the technical data or really any basis for my opinion...but you already know it:

You'll be sorry!!!

 

[Jimma]

My M35A2 came out of service singled out with 11x20's. The government did it.

 

[ranchand]

What size tires? Isn't the military running singles on all the 5 tons now? Sounds like your buddy has been retired for a while?

 

[NSCoyote]

i seem to recall the HET M1070 is also singled out, and its the mil's choice to have it singled........
personally i like how singled trucks run and handle and for the most part commercial super singles/wb tires dont lose much for a load limit then duals in comparision and they save a mbunch on fuel consumption (some have noted a 10% savings) and come on they just look meaner

 

[91W350]

I have a M35A2 on 1100s singled, came out of the military that way and drives great, the extra road speed is nice, so is the easy steering. They are a road tire though, I forget the numbers now, but it seems like the single rating for the 1100 X 4 is more than the truck is rated for. I have not been in mud with it yet, but suspect it would be pretty slippery as there is very little siping or cutting to the outside. Glen

 

[Castle Bravo]

Other than line haul stuff 916A3s, 915A2s, etc... I don't think there are any modern military vehicles that are not running single tires.

 

[jwaller]

Installing a turbo in my M818 this week in anticipation of singleing her out in the near future (All ready have my new tires - Goodyears and wheels) .. A retired Marine Corp Buddy of mine with 30+ years of service as a Maintenance Chief is totally against the concept for that series vehicle .. here are just a couple of issues he brought to my attention .. Thoughts, comments experience with these issues would be appreciated ..


MarCor went to super singles on M818’s and some other MV’s and switched back – Reason – Vehicles couldn’t handle rated loads and at times “laid over” the tire creating a dangerous control problem. Later, they got Goodyear to fix the problem with some kind of change in specs.

They’ll make 900 Series MV’s go faster (70+) MPH, but on 800 Series the gearing won’t allow it, but transmission check cycles will have to be increased because the trannies will be running harder and wear out faster?

Super singles are non-performers in snow and ice conditions,

His information seems to be a bit off. The tires will not make the eng or trans or transfer turn 1rpm faster, they will in fact turn the same rpm as they do now, thats the way you get more MPH without any extra rpm.

As far as more wear on the trans, maybe 1st gets a tad more strain but not much.
The tires are in fact rated to carry way more than the truck can but that doesn't change anything, you still can only haul what the dataplate says you can. that way you don't overload the truck chassis or frame or brakes.

singles in snow/ice should be better as they will have a higher ground pressure and thus better coefficient of friction.

 

[NSCoyote]

His information seems to be a bit off. The tires will not make the eng or trans or transfer turn 1rpm faster, they will in fact turn the same rpm as they do now, thats the way you get more MPH without any extra rpm.

As far as more wear on the trans, maybe 1st gets a tad more strain but not much.
The tires are in fact rated to carry way more than the truck can but that doesn't change anything, you still can only haul what the dataplate says you can. that way you don't overload the truck chassis or frame or brakes.


singles in snow/ice should be better as they will have a higher ground pressure and thus better coefficient of friction.

depends on the deth of the snow and whats under it, think snow shoes vs normal footwear. with snow shoes the weight is distributed over a larger area therefore reducing the actual preasure aplied from the weight of the vehicle on the contact surface *less lbs per sq inch*. if your operating on a surface of snow with pavment under it it is better to run the narrow contact patches of the duals to get you down onto the pavement easier to provide better traction, with deeper snow (talking feet not inches here) or snow with unknown substrate (marsh,bog, creek etc) a wider tire is is a bit more ideal as it will float you better and keep you from sinking to far down but unless you have deep cut lugs the float will do no good as you will likely just spin unless geared REALLY low.

 

[drgreg]

The M939 series trucks did have some issue with flipping, then the ABS was added. I don't know if the issue included singles.

 

[91W350]

if your operating on a surface of snow with pavment under it it is better to run the narrow contact patches of the duals to get you down onto the pavement easier to provide better traction.

You cannot possibly be talking about NDTs as they are about as dangerous as they come in these conditions. There is no bite on ice or a thin layer of snow for an NDT. They have the rib in the center of the tire with no siping grooves, almost as bad as trying to run a drag slick. They work good if you have something for the round ribs on the side to hook to, but on a smooth slick surface, they are not anybody's tire of choice. I creep around corners and try to do that off power as much as possible. They are extremely dangerous ice/snow/pavement tires.

 

[NSCoyote]

You cannot possibly be talking about NDTs as they are about as dangerous as they come in these conditions. There is no bite on ice or a thin layer of snow for an NDT. They have the rib in the center of the tire with no siping grooves, almost as bad as trying to run a drag slick. They work good if you have something for the round ribs on the side to hook to, but on a smooth slick surface, they are not anybody's tire of choice. I creep around corners and try to do that off power as much as possible. They are extremely dangerous ice/snow/pavement tires.

i wouldnt even put NDT's on my lawn tractor let alone a vehicle i intend to use on canadian roads, unless you modify the lugs of an NDT with a tire knife they are useless and pose a huge safety issue in snow, ice conditions or loss gravel.

if you cut the lugs of the center line of the NDT to remove the red in the attached picture it would make a considerably better snow tire with some added siping in the horizontal lugs it would make for decent tire

 

[91W350]

You get a lot more snow up there than we do! You think a pair of 7 or 8 inch wide tires sink into the snow better than a single 14 to 16 inch wide tire? That is interesting to me. Looks like the flotation would be close, although the military singles do have some puffy sidewalls. We have to hunt for a four foot drift after a good snow here, you guys wind up with more than that piled up on the ground, no drifting necessary. Around here a taller narrow single tire will do much better in our mud and snow conditions than a wide tire or a dual tire application. I cannot speak for the wide profile singles like the 1400s, I have to base off of 900X20 or 1100X20 tires. We want a straight sidewall and a tall narrow tire, let it cut down to whatever is solid below. It is interesting how different people and areas see tires so vastly different. Glen

 

[91W350]

No argument in the cutting of the NDT making them work better, you are cutting out a third of the wear though as they are so rounded, they ride on the ridge.

 

[NSCoyote]

when comparing dual 8" tires to one 16" tire on snow up to hub height, the ground pressure is equal as well as the actual footprint the only real benifit over the duals is the gap between creates a natural self cleaning lug, but in really deep snow over the hub height that gap can also be a downfall is it can create a natural jack point where it fills up and packs in with snow so much that it makes your duals act like a 20" wide NDT unless your spinning them fast enough to clean it out or you brakes are warm enough to keep the snow from stickign to the rim space

 

[91W350]

We run into that all the time. Guys will compress snow between the dual tires and get stuck in less than six inches of snow. Especially if the snow is packing a lot of moisture. It will pack solid in there and float the tires away from the solid surface. It does not take much to stick a tractor on road tires in those conditions.

 

[NSCoyote]

We run into that all the time. Guys will compress snow between the dual tires and get stuck in less than six inches of snow. Especially if the snow is packing a lot of moisture. It will pack solid in there and float the tires away from the solid surface. It does not take much to stick a tractor on road tires in those conditions.

teach em how to use one of these
http://www.renovateforum.com/attach...ng-boards-not-straight-stanley_wonder_bar.jpg

one of the first things i learned as a kid wanting to drive a rig was to help clean the snow out my dads and uncles duals LOL

 

[Castle Bravo]

I seem to recall talking to a 88M that was in Iraq towards the beginning of the conflict saying they had taken their M939 series tractors and put 10 11R20 tires back on them for highway use. He said they ran slower, but were more stable and had to stop less because they could continue on with a flat or two.

On the topic of NDTs/NDCCs -

Why is it that when it comes to the rest of the vehicle, the majority brings out the "The designers knew what they were doing" card, but with tires, we call them dangerous? I'm sure that tire technology has come a long way in 70 years, but what did they not know about mud, snow, and ice in the 1940s?

Keep in mind that I live south of where it snows in Arizona, and I've only even seen snow maybe twice in my life. I've never driven on ice or snow and I stay out of the mud - responses should be tailored with that in mind.

 

[91W350]

I have been getting decent service out of the NDTs in mud, even though our mud is really slick and not normally very deep. What happens on ice or thin hard packed snow is the tires do not have any gripping edges. They ride on that narrow zig zag line down the center of the tire. I never tried airing way down to run on the ice. It is not unusual on really slick surfaces to have to back up to complete the turn, the rears will just plow the fronts sideways. Sometimes when turning after a fresh rain, I can feel the tires plowing. What really makes them dangerous is trying to stop. They just do not grip the icy surfaces. In sand or mud, they can sink and take advantage of the edges on the face of the tread, on ice, it is all on that narrow rib that has no grooves, siping, nothing. If you have a few inches of snow or even two inches of snow that has not been hard packed, they get along fine. It is a sick feeling when a truck the size of a deuce starts sliding towards the lowest side of the roadway. I normally drive slow enough on ice that I can roll to a stop without brakes, just using engine braking and the friction of the gear oil on the gears. I learned first hand years ago with my first Willy's Jeep, got a rude reminder with my M715s and did not take long to figure out deuce's are in the same boat on NDts. Glen