Deuce Rough Terrain Limitations

[therealquaid]

Hi guys, after extensive reading on this forum and talking to a few MV owners I’ve been seeing what some of you do off-road with your Deuces. Not that I need to do this with the M35A2, but if I wanted to, what kind of modifications would you do to be comfortable taking your Deuce on terrain like this?

To be clear, I’m asking about a very specific type of terrain, I’m wondering if these mods would help in a situation like this (none of these videos are mine):
https://youtube.com/clip/UgkxkABBAi5eJS8AHqf30W4iFCHd-RYsQemS

*The truck in the video is a modified Mitsubishi Fuso Box truck 4x4 conversion, it has a 131mm wheelbase, 3mm short of the average bobbed Deuce.

The first mods that come to mind for me are:
- Bobbing the truck, shorter wheelbase would allow for picking better lines in narrow tracks.
- Replacing the cargo bed for a torsion free subframe to allow for further frame flex keeping all wheels on the ground increasing traction. The M275 would also be an example of allowing more frame torsion.
- Larger Super Single tires for better ground clearance and tire area grabbing onto the ground.
- Beadlocked rims to avoid the issue of inner tubes slipping when airing down on stock rims.
- Air Locking Differentials for more traction.
- Hydraulic Power Steering to help navigate the tight narrow ditches and rocks.

The closest examples I’ve found on video are these other 3, although neither of them present the obstacle shown in the first video with the short truck.

Video 2:

Video 3:

Video 4:

I’d appreciate any ideas from anyone who thinks these mods would not help as much, or if there are others that I haven’t thought of.
Thanks!

 

[porkysplace]

Just my thougths bobbing the truck loses a lot of it capabilities from the the third axle .
Larger super singles drain power (there not a powerhouse to start with) and raises the center of gravity
especially with a box like in the video .
It all comes down to intended use , as most mods have pluses and minuses you have to evaluate for your own intended purpose.

 

[therealquaid]

Just my thougths bobbing the truck loses a lot of it capabilities from the the third axle .
Larger super singles drain power (there not a powerhouse to start with) and raises the center of gravity
especially with a box like in the video .
It all comes down to intended use , as most mods have pluses and minuses you have to evaluate for your own intended purpose.

I agree! When it comes to the specific example in the video however, do you think smaller tires and having the 3rd axle + longer wheelbase might improve performance getting over that hump? To me it seemed like the stock Deuce could bottom out and get the driveshaft stuck on that hump.

 

[msgjd]

my pic below is obviously not a deuce, but a deuce would have very little problem doing the same stunt, stock... as far as what the M35A2 in your posted vid #3 is doing, having one with shorter wheelbase (ie: bobbed) , no winch, and more tire height would not have bottomed out on the riverbank like that ... Even a stock jeep would've hit its belly in same manner.. You are obviously on the right track with your wish-list of mods, but you need to keep in mind in doing those mods, there will be gains in some capabilities, and losses in other ways.. It will be very difficult, if not impossible, to build one with 100% positive gains off-road/on-road .... It all depends on what you want to do with yours.. They are already balanced about as good as they can get for on-road/off-road, keeping it stock

 

[therealquaid]

my pic below is not a deuce, but one would have little problem doing the same stunt, stock... as far as what the M35A2 in your posted vid #3 is doing, having one with shorter wheelbase (ie: bobbed) , no winch, and more tire height would not have bottomed out on the riverbank like that ... Even a stock jeep would've hit its belly in same manner.. You are obviously on the right track with your wish-list of mods

View attachment 893892

Thanks, I appreciate your picture! I haven’t had the chance to see ANYONE put their trucks at angles like this until yours

 

[msgjd]

I haven’t had the chance to see ANYONE put their trucks at angles like this until yours

as is with all of our other trucks, it is a work truck ... Was having its sprag tested after being serviced for being sticky / non-functional .. We don't do any extreme off-roading with any of them, except decades ago with the "XM38A5" .. However they all continue to do off-road/on-road tasks related to construction and farming , which sometimes does put them in contorted positions at the max of their suspension system

 

[porkysplace]

I agree! When it comes to the specific example in the video however, do you think smaller tires and having the 3rd axle + longer wheelbase might improve performance getting over that hump? To me it seemed like the stock Deuce could bottom out and get the driveshaft stuck on that hump.

Approach and departure angles are 38 dergrees.

 

[cattlerepairman]

A few thoughts here.
The Mitsubishi has full lockers in both axles. You can see that clearly with the front axle; the tire that has grip on the rock and the tire that is in the air both spin at the same speed.
A Deuce off-road will benefit from three lockers, ideally air actuated so you have full control.
6x6 will beat 4x4 in most conditions unless very tight turning is an absolute need. Can't beat having another two wheels on the ground and pushing. That Mitsu 4x4 is also a bit top heavy; won't take much of a sideways lean.

The Deuce is limited by its sheer dimensions on many trails made for Jeeps and small off roaders. You do not have the luxury to pick a great line; you need to take what you can fit in.

I agree with the taller tires; they have a larger circumference and will put more tread down, compared to 9.00-20 stock tires. The Deuce is heavy and where that matters is soft ground. The video of the truck climbing the river bank and loose gravel is typical. As long as the tires grab, you are good. As soon as they sink in loose ground you better do not lose momentum or take your foot off the throttle. Any time I really get mine stuck it is in bottomless soft ground that looked enticing until I put the weight of the truck onto it. The front axle on the w/w truck is almost at max weight, even with an empty bed. Remember that when off roading....

I do not think the Deuce needs a lot of mods to be more capable off-road, other than tires and lockers. Sure, if you are leaning towards the insane kind of offroading, you may want to spread the rear axles to allow gigantic tires etc. I am talking what most people would consider still "normal".

Soft sand, with tires not aired down, and an incline is enough to get you stuck.....you are still driving a 13500 lbs truck.

 

[therealquaid]

A few thoughts here.
The Mitsubishi has full lockers in both axles. You can see that clearly with the front axle; the tire that has grip on the rock and the tire that is in the air both spin at the same speed.
A Deuce off-road will benefit from three lockers, ideally air actuated so you have full control.
6x6 will beat 4x4 in most conditions unless very tight turning is an absolute need. Can't beat having another two wheels on the ground and pushing. That Mitsu 4x4 is also a bit top heavy; won't take much of a sideways lean.

The Deuce is limited by its sheer dimensions on many trails made for Jeeps and small off roaders. You do not have the luxury to pick a great line; you need to take what you can fit in.

I agree with the taller tires; they have a larger circumference and will put more tread down, compared to 9.00-20 stock tires. The Deuce is heavy and where that matters is soft ground. The video of the truck climbing the river bank and loose gravel is typical. As long as the tires grab, you are good. As soon as they sink in loose ground you better do not lose momentum or take your foot off the throttle. Any time I really get mine stuck it is in bottomless soft ground that looked enticing until I put the weight of the truck onto it. The front axle on the w/w truck is almost at max weight, even with an empty bed. Remember that when off roading....

I do not think the Deuce needs a lot of mods to be more capable off-road, other than tires and lockers. Sure, if you are leaning towards the insane kind of offroading, you may want to spread the rear axles to allow gigantic tires etc. I am talking what most people would consider still "normal".

Soft sand, with tires not aired down, and an incline is enough to get you stuck.....you are still driving a 13500 lbs truck.

View attachment 895242

Nice observation on the Fuso’s lockers
Thanks for those insights and that picture! I really appreciate it as it got me thinking a bunch.

Since some guys on here were reporting their inner tubes slipping on stock rims with aired down 395s, would you say it’s actually best to upgrade from stock rims?

For sure there’s no question that doing what these trucks are designed to do -carrying heavy loads off-road- 6x6 is superior, not to mention better looking!
But considering driving unloaded, wouldn’t losing an axle redistribute more weight onto the single rear axle (where before it’s spread between 2 axles) maybe give it some more traction rather than less?

The reason I ask is that a guy I know mentioned seeing unloaded bobbed deuces always climb further than the unloaded 6x6s. He bobbed trucks for a few people and explained that the weight gets redistributed in a way that added traction.

I’m not sure, but it seems like this video shows an example of this effect on weight distribution, when the tires in the bed slide over to the rear axles at 0:50s it coincides with the truck losing traction.

Duce and a half crawls right up it. | By Dan Domski | Facebook

Duce and a half crawls right up it.

fb.watch

 

[therealquaid]

The Deuce is limited by its sheer dimensions on many trails made for Jeeps and small off roaders. You do not have the luxury to pick a great line; you need to take what you can fit in.

I figured maybe bobbing the Deuce might help in this aspect since it’s 134” wheelbase becomes almost as short as the CUCV (131” wheelbase same as the fuso) allowing to pick better lines. The hydraulic power-steering would help with this as well maybe? That way you could steer yourself better to avoid rocks and slightly steer while having all differentials locked.

 

[montaillou]

Do you have near unlimited funds for your wish list? Maybe consider an engine swap, but keep the original transmission.

I agree with others to stay 6x6 and keep in mind that some dually set ups have more rubber on the ground than super singles. For instance, your 395's or 15.5" compared to my 11R24.5 dually set up and I have over 20" of tire width on the ground in the rears. And there's something to be said for unsprung mass of going with smaller/lighter tires - in some situations this could be critical.

 

[rustystud]

Nice observation on the Fuso’s lockers
Thanks for those insights and that picture! I really appreciate it as it got me thinking a bunch.

Since some guys on here were reporting their inner tubes slipping on stock rims with aired down 395s, would you say it’s actually best to upgrade from stock rims?

For sure there’s no question that doing what these trucks are designed to do -carrying heavy loads off-road- 6x6 is superior, not to mention better looking!
But considering driving unloaded, wouldn’t losing an axle redistribute more weight onto the single rear axle (where before it’s spread between 2 axles) maybe give it some more traction rather than less?

The reason I ask is that a guy I know mentioned seeing unloaded bobbed deuces always climb further than the unloaded 6x6s. He bobbed trucks for a few people and explained that the weight gets redistributed in a way that added traction.

I’m not sure, but it seems like this video shows an example of this effect on weight distribution, when the tires in the bed slide over to the rear axles at 0:50s it coincides with the truck losing traction.

Duce and a half crawls right up it. | By Dan Domski | Facebook

Duce and a half crawls right up it.

fb.watch

When you "bob" a Deuce you lose weight which comes in handy in soft ground. Driving in the Marines taught me quite a few lessons on driving in adverse conditions. One was keeping traction. The more wheels in contact with the ground the better, so watch your "lines" . That means if you have to, take out a few bushes or small trees. Just drive over them, the Deuce can handle it. Also airing down or adding chains helps. I have a complete set of chains on board just for this kind of situation.
Also if I could afford it, I would add "Air Lockers" to all differentials just like "cattlerepairman" mentioned. That is the BEST option out there.

 

[HanksDeuce]

When you "bob" a Deuce you lose weight which comes in handy in soft ground.

With all the gear on my bobbed deuce it still weighs 13,040 lb on the certified scales at work. The (5) 53" tires and tool box with recovery gear bring the weight back that was lost from cutting off about 3 ft of frame length and removing the back axle setup. I never looked into the weight difference from the multifuel and 5 speed to the Cummins 6BT and Allison AT545.

 

[therealquaid]

With all the gear on my bobbed deuce it still weighs 13,040 lb on the certified scales at work. The (5) 53" tires and tool box with recovery gear bring the weight back that was lost from cutting off about 3 ft of frame length and removing the back axle setup. I never looked into the weight difference from the multifuel and 5 speed to the Cummins 6BT and Allison AT545.

Your weight might be the same but it sounds like you were able to redistribute it even more then, so those 2 rear axles that would have been unloaded now is one single rear axle with better weight distribution and more traction.

This is just an assumption of mine, but I figured this is the case because the truck was designed to perform carrying a heavy load off-road. So if there is no heavy load these design changes could actually improve it off-road.

 

[therealquaid]

When you "bob" a Deuce you lose weight which comes in handy in soft ground. Driving in the Marines taught me quite a few lessons on driving in adverse conditions. One was keeping traction. The more wheels in contact with the ground the better, so watch your "lines" . That means if you have to, take out a few bushes or small trees. Just drive over them, the Deuce can handle it. Also airing down or adding chains helps. I have a complete set of chains on board just for this kind of situation.
Also if I could afford it, I would add "Air Lockers" to all differentials just like "cattlerepairman" mentioned. That is the BEST option out there.

Makes sense. So wouldn’t hydraulic power steering necessarily improve picking better lines?

 

[therealquaid]

Do you have near unlimited funds for your wish list? Maybe consider an engine swap, but keep the original transmission.

It’s not really a wishlist

I’m new to the truck and although mine already has mods, I’m trying to educate myself from anyone who has put their truck regularly in situations like that. I want to understand better how each component influences off-roading, by learning how the truck could possibly do better in that specific situation in the video with the Fuso box truck.

In this sense, yes, regardless of budget I’m interested in anything that would greatly improve the truck in that situation so the engine upgrade makes sense.

Would I necessarily do all of this to the truck? Maybe not since a Deuce doesn’t have to be in those conditions all the time, but those conditions are what I’m trying to learn what could do better.

 

[therealquaid]

I’m not sure, but it seems like this video shows an example of this effect on weight distribution, when the tires in the bed slide over to the rear axles at 0:50s it coincides with the truck losing traction.

Duce and a half crawls right up it. | By Dan Domski | Facebook

Duce and a half crawls right up it.

fb.watch

Does anyone have any thoughts on this video if you think it shows weight distribution affecting traction?

 

[montaillou]

Just drive over them, the Deuce can handle it.

I took out a chain link fence post. Didn't notice until I got out.

It’s not really a wishlist

Well, a Cummins 6 BT might about double your HP and torque, depending on which version of engine you get. Jeepsinker (Tactical Repair on YouTube) has videos about the conversion.
I did an engine swap, you can see it here. Not very technical, but lots of pretty pics.

 

[therealquaid]

I took out a chain link fence post. Didn't notice until I got out.



Well, a Cummins 6 BT might about double your HP and torque, depending on which version of engine you get. Jeepsinker (Tactical Repair on YouTube) has videos about the conversion.
I did an engine swap, you can see it here. Not very technical, but lots of pretty pics.

Thanks for sharing that, that was a nice read! I’m sure you’d feel a whole difference with that much torque.

Do you happen to know if you had a significant change in your mpg with the 6BT?

 

[matt444]

Don't Bob it, you'll lose traction
Air lockers help a lot
Tight trails and rock climbing will require power steering
If going over hills or rocks, move fuel tanks and battery box to the bed
remove the tool box
On rally steep hills truck won't have enough power to make it
After all that, the biggest issue will be ground clearance



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