M1031 with 4:56 gears, sustable for road/ highway driving?

[iamspencer]

hey was lookign at a m1031 as a work truck, im a welder and it looks liek a great utility body, are they sutable for road and highway use?

has anyone ever put 4:10s or other gears in them?

were they really underpowerd?

any help or advice would be great thanks
-spencer

 

[acmunro]

55 is your sustainable top speed with 4.56 gears. You can go a little faster for short periods.
They are no powerhouse for towing, but move themselves around pretty well. I used mine to tow a crewcab dually from SC to PA on my car trailer, it was slow over the mountains, but got the job done.

 

[iamspencer]

anyone think 4:10s would be to high?

 

[4x4 Forever]

4.10 would be excellent, but I believe you would have to change the carrier as well as the ring gear/pinion. I was investigating this myself, and the gear swap alone would be affordable. Having to change the carriers would be cost prohibitive, another 800 clams for both ends. Figure I could buy mucho diesel for the cost of changing the carriers.

It is one stout truck, should be no problems banging around with a Lincoln 350 in the back.

 

[southdave]

I have 87 A one ton dump with a 4 spd and 6.2 & 4:10 and four speed works great

 

[iamspencer]

also are the onboard welders anygood?

 

[acmunro]

The actual M1031 CMV uses a welder that plugs into the trucks PTO powered generator panel. Most M1031s do not come with the welder. The M1028 that is converted into the Contact Maint Vehicle using the old Dodge utility bed have gasoline powered (4 cyl air cooled Wisconsin) Hobart welder/generator. I have not had a chance to weld with my Hobart yet.

 

[iamspencer]

thanks for all the info guys

 

[bushhawg73]

If I was going to swap the gears I would look for a 14 bolt with 4:10 gears. I would not change the front end. I would just be careful when locking the 4X4 in. As long as you do not do it on a hard surface you should be ok. I once had a friend with a slightly higher ratio in the front than it the rear. In the mud that thing always did very well. I believe that the front turning slightly faster helped it in some way.

 

[blzrgb]

That ratio difference is not much, but it's asking for trouble.

 

[4x4 Forever]

Needing 4WD usually comes down to, I need it now!!, and then the 'I forgot' syndrome comes into play. Two ratios that are that far apart can do major damage to the drivetrain. Mainly the transfer case, I have seen u-joints in pieces as well. If you are going to change gears, do it the right way. This way you wont have to shell out $$$ on "I forgot".

Not all gears are the same between manufacturers, but the difference is small. Some Ford? and Jeep? trucks came with 4.10 in the front and 4.09 in the back, or vice versa, that difference is negligible. Yes, the mudders usually go with higher gears in front to pull them along, but these are specialized uses and not used as a daily driver. Anything more than that is really asking for trouble.

Just my

 

[blzrgb]

 

[Lebowski]

Maybe instead of changing gears just go to a slightly larger tire like 34" or 35"?

 

[Taz]

I have 4.10's in my M1031. Nothing runs well up here (7200 ft) unless it has a turbo! A better idea is an overdrive, either a gear vendor or 700r4 or 4l80E and leaving the 4:56's!!!
Been there, done that!

 

[91W350]

I would not run a 4:10 rear with a 4:56 front, that is a half a turn of the driveshaft per single revolution of the tires. 4:55 and 4:56 would be okay, 4:10 and 4:11 would be okay. We are talking about the rear tires pushing the front tires. I am betting it would be crazy in the slick. A tremendous load on the driveline in dry conditions. I just drive mine 48 to 50 and take in all the stuff I was missing before.

 

[acmunro]

It's amazing how much more you see driving 48 to 50/55.

 

[bushhawg73]

My plan was not perfect as you can see. I was just giving you somthing to ponder. Personally now that the tranny swap has been mentioned I must say that I would rather go that route than have different axle ratios. That and the fact if it was reversed, 410 in front and 456 in the rear. The truck I mentioned earlier was a F150 with somthing like 308 in the front and 355 in the rear. It would really pull when we played in the mud on the weekends.

 

[1stDeuce]

I did the tranny swap thing in my current project M1008. Just found a complete 700R4/208 out of a civy 6.2L truck. Put a cooler on it and it'll be fine. Got me a lower 1st gear too, which is nice. I have the best of both worlds now, 4.56 gears and a highway capable truck. Now I can run it 65mph with no issue at all, and even 70 is probably not a big deal, about 2300rpm on the 33's I have. For comparison, a normal M1008 on stock 235's has to turn over 2700 RPM just to get to 55mph. The 4.56 gears make life pretty easy for the 700r4 as well. It should last a long time!!

C

 

[truck0590]

Problem with tranny swap on M1031 is that it uses a NP205 not the 208. M1031 needs the 205 for the PTO output to drive the generator. So it is not as easy a swap as there was only 1 year and limited models of civie trucks(if I remember right) that had an overdrive tranny. Not that it can't be done, anything can be done with conversion parts and fab work, it just is more difficult and expensive.

You might consider looking for a an axle set with 4.10 or 3.73 gears. They were common and are out there and can usually be had cheap. Then sell yours, they are very desirable to the rest of the wheeling community. Probably make money on the deal. Cheaper then to add lockers as needed.

Truck

 

[12vctd]

np205 to 700r4 is a very simple swap. Theres both a spacer or some choose to cut the tailshaft the required amount, or install a new tailshaft. But the spacer (I am having trouble finding in on my pc right this moment) is cheap and works very well. its a 2 inch spacer used to replace a 700r4 with a th350. This is by far the cheapest way to offset the 4.56 gears and as mentioned before with allow a steeper first gear, and od. That with a 33 inch tire you will have gearing to help the 6.2 and have a good cruise speed.