has anyone bult a deuce hemtt yet?

[jdknech]

i have done a lot of searching and havent found much, i like the baby hemtt, it looks really cool! i want to build a poor man's hemtt, with 4 wheel steering, and all has anybody done this yet???

 

[jdknech]

I've been watching the baby hemtt ( and my hat is off to jones, great job!) but i want the longer wheel base, and quad steering......

 

[wreckerman893]

A few of us have kicked the idea around.

My thought was to use the walking beam setup from the rear to mount steering axles on.

Basically welding two rear halves together to make one unit.

There are a butt load of HEMMT cabs on the market now so finding one should be easy.

The big issue (to me) is making sure the steering is safe and reliable.

Other issues might include....transmission linkage if using a manual (HEMMT's are automatic), cooling (getting enough air through the radiator) and cobbling together an electric system.

Using HEMMT rims with deuce pattern inserts welded in would allow use of HEMMT tires which would give it an awesome appearence.

I would opt for a tractor version but a cargo would be cool too.

 

[Jones]

The problem I've run into through the baby HEMTT is space. The deuce frames don't allow much room for steering components, oversized (for a deuce) axles and the like.
If you want a longer finished truck, start with a long deuce frame... a stock M35 will be pretty stubby.

A HEMTT cab hangs out over the frame ends by a good two feet and need to be well supported 'cause they're heavy.

If you're talking a steer axle front and rear then telling the rear axle when to turn and when to straighten out is gonna be interesting but not insurmountable.
If you're thinking two steer axles under the front-- read on.
The rear suspension 'bogie' out from under a deuce would probably be adaptable for two steer axles but I'm not sure what it would do to turning radii what with torsion bars and stuff in the way of tires when turned for steering.
And all that's if you can even get 1600X20's to fit within the rear spacing without their treads rubbing. Two steer axles won't get any farther apart regardless of whether the 'bogie' assy. is under the front or the rear of the truck.

The next hurdle is gonna be a steering box. Deuces use a box with the input shaft to the rear. HEMTTs use a box that sits ahead of the forward steer axle and has an input shaft that points towards the driver's side; LVS cabs use a steering box whose shaft points out the front.
I ended up with a custom built box that's closest in design and function to an early Mack COE tractor... $1,459.00 without core. Expensive but all other alternatives ended up looking like a cross between an Erector Set and a Rube Goldberg invention.

Flipping a deuce box won't cure your problems as the HEMTT steering shaft works backwards-- turn the steering wheel to the left and the shaft turns to the right.
Think of a deuce box with the shaft extended out the from and you'll see which way the input shaft needs to turn to get the pitman arm to push or pull the correct direection.

Another fly in the steering ointment is that the #2 steer axle on any two steer axle set-up turns less than the #1 steer axle. To deal with this, HEMTT's #2 steer axles are controlled by a slightly underdriven remote steering box (no input shaft) that takes it's commands off of the main box.

Automatic trans is a must or you're gonna be wrestling with clutch and shift linkage 'til the day you throw in the towel.

Not trying to discourage you but it's important to go into this with your eyes open.

 

[jdknech]

thanks for all the info!! as far as the length, i was thinking about welding 2 frames together nose to nose. as far as the front steer axles, i could move the suspension inboard (kinda like tubing the rear of a drag car) to clear the steering......

 

[jdknech]

here is my idea for the steering linkage..... still workin on the steering column to gear box.... i would rather not spend $1400 on a steering box, but......

 

[jdknech]

sorry i forgot to explain my very crude drawing! lol if you put steering arms on the passenger side of the front axles, and make the rear arm longer than the front, that should take care of the steering problem! (the 2 axles not turning the same distance)

 

[Jake0147]

Any time I've seen that linkage, the drag link from the front to the rear has been on the same side as the steering gear. I think to limit the number of "links" in the chain between the steering gear and that last tire to recieve "input".

Just for consideration, (I am not claiming to have seen a lot of these, nor am I claiming to be an engineer...), but if the front axle were stock, and the "new drag link" to the rear axle were added to the original steering arm, on the front axle, outboard from the original drag link to the steering gear, then would that not give you the same geometry change that you need while only modifying/custom making one single arm, as well as "somewhat" branching the system so that every ball joint does not get the wear from being beaten on by every tire?

Just thinking out loud... Take it for what it's worth.

 

[Snarky]

This is just my opinion but, it seems like it would be a bit silly to start with a deuce for a hemmt conversion, sure you get a cheap entry price, but starting with a 5 ton gets you 10 bolt hubs, auto tranny, larger wheel clearances, allegedly better braking setup. It's almost as if it was made to be modified.

I think to get one HEMMT monstrosity you would need to start with two donor trucks, the benefit to using a deuce is that they are cheap, and its less horrific to some if you cut them up to make something cooler.

As for me? I would like to see some kind of redneck HEMMT cabbed shop truck rv beast as an 8X8.

 

[wreckerman893]

I agree that the 5 ton platform would be the ideal candidate...I also agree that it would cost a butt load of money for two donor trucks...unless they were already partially parted out......you just need the frames, one steering axle and one engine and tranny.
Since 5 tons dont get parted out for Rockwells but mostly for sheet metal there is an opportunity.
If you used 900 series trucks the transmission issue would be solved since they came with an automatic. There was a huge sale of residue 900 trucks a few months ago somewhere out west. This would also give you straight air brakes instead of air/hydo.
If you used a long bed 5 ton frame (with the walking beam suspension) for the front you would have the overhang needed for the HEMMT cab to mount in front of the steering axles.

Just stirring the pot.

 

[jdknech]

well i agree that the 5 ton would be the best, but i all ready have 1 complete deuce, and a frame with axles. i also have a line on a CAT 3208 with a auto trans...... the only thing i need now is a cab, all the ones i find on GL say they have to be destroyed!

 

[jesusgatos]

...transmission linkage if using a manual (HEMMT's are automatic), cooling (getting enough air through the radiator) and cobbling together an electric system.

The manual transmission and shifter linkage shouldn't present much of a problem. You can operate any manual transmission shifter remotely by controlling it with two morse-style push-pull cables (one to control front/back and one to control side/side movement). You can put the shifter anywhere you want and the shifter feel is surprisingly precise.

The next hurdle is gonna be a steering box. Deuces use a box with the input shaft to the rear. HEMTTs use a box that sits ahead of the forward steer axle and has an input shaft that points towards the driver's side; LVS cabs use a steering box whose shaft points out the front.
I ended up with a custom built box that's closest in design and function to an early Mack COE tractor... $1,459.00 without core. Expensive but all other alternatives ended up looking like a cross between an Erector Set and a Rube Goldberg invention.

Flipping a deuce box won't cure your problems as the HEMTT steering shaft works backwards-- turn the steering wheel to the left and the shaft turns to the right.
Think of a deuce box with the shaft extended out the from and you'll see which way the input shaft needs to turn to get the pitman arm to push or pull the correct direection.

Another fly in the steering ointment is that the #2 steer axle on any two steer axle set-up turns less than the #1 steer axle. To deal with this, HEMTT's #2 steer axles are controlled by a slightly underdriven remote steering box (no input shaft) that takes it's commands off of the main box.

I would encourage someone intent on building a vehicle like this to consider using a fully-hydraulic steering system. That would completely eliminate all of the problems associated with steering linkage and ratios between axles. A convincing argument can be made that a properly engineered system is every bit as safe as any other steering system, and nobody has ever been able to furnish evidence to support the popular belief that fully hydraulic steering systems are illegal to drive on-road.

This is just my opinion but, it seems like it would be a bit silly to start with a deuce for a hemmt conversion, sure you get a cheap entry price, but starting with a 5 ton gets you 10 bolt hubs, auto tranny, larger wheel clearances, allegedly better braking setup. It's almost as if it was made to be modified.

Yup yup. I think that would be the BEST way to tackle a project like this.