Loading the 5th wheel for traction

[Junglemist]

it would be cool to have different beds you could switch out when you need the truck for something other than pulling a semi trailer .maybe if you put a fifth wheeel plate under the bed and had some screw jacks to lock it into the frame

I have considered converting my M35 into a tractor and have pondered the same thing. It would be awesome to have the versatility of a tractor and yet still be able to mount a shortened cargo bed on it. For the trips to the beach, canoeing, etc.

 

[grounded]

HMM interesting idea TM, and guys. NOW i got a idea. NOT that i need a bed like that. but man the 818 has some pulling power.

 

[oilcan]

I think it's the transportability guides that show the axle weights and cg of the 818 and other trucks. From what I remember the line drawing shows the 818's cg right at the top of the framerail, just behind the cab. Not bad if you ask me.
But now that you mention it, I might just strap some ballast out back to try it out. Maybe a load of 5 ton tires or some scrap railroad track.


That spare tire was for the M200 and I didn't want to load it back up at the end of the weekend at haspin. It did make a handy spot to stash the murderous lifting strap, though.

 

[cranetruck]

The 818 has a lot of unsprung weight in the rear, probably close to 1,800 lb in the wheels/tires alone, which helps for traction. My 8x8 only has 750 lb in the wheels/tires in the rear. Just to be even with the 818, I'd have to add a couple of thousand pounds considering its lighter suspension also.
The 5th wheel and ramp all bolt on in my case, so switching to a cargo bed wouldn't be difficult...however, I'd still like to see a solution keeping the 5th wheel in place.

 

[tm america]

cranetruck how much weight is on the front as compared to the rearcuz those tatra trucks are set up pretty similar and with two axles in the front it helps them alot of times not having much weight on the back. like when they are going over hills and when being flexed out it lets them balance on the rear front axle rather than high centering on the frame between the middle axles.since you have two axles holding the load in the front they dont seem to dig in the front like 6x6s do .i'm sure it feels funny driving something that is balanced out like that ,but it seems to be an ideal set up from what i've seen.even the six wheel drive tatras do way better off road than a regular 6x6 cuz they have two axles in the front .using the rear front axle as a pivot when going over hills works great since most of the weight goes where the traction is .if you load the back the same as the front the center of gravity will be in the middle of the truck making it want to high center on the frame between the middle axles

 

[tm america]

plus putting more weight on the back will make the truck way harder to steer off road .by making the rears have more traction it will try to push the fronts.think of your truck as a front wheel drive car rather than a rear wheel car.you want to put the weight on the steer tires since they have enough floation to keep from digging so as long as you arent dragging the diffs .the more weight you can put on the front the better you will be able to steer off road .the only ill effect i see is when on road the drive tires dont have much weight on them so its kind of a trade off you get great off road for less than prefect on road .

 

[cranetruck]

TM, here is the info you asked for.

 

[tm america]

ya i'd say it's lite in the backmaybe you could make some counter weight boxes for 1/2inch plate to fit in between the frame rails in front and behind the fifth wheel then fill em with concrete .you could put some pins sticking up for them to sit on then just pin em in place.and you could put some lifting rings on the top so you could get them off easily with the crane.that would keep it looking stock from the side but then it would be more drivable on the street and you could use the fifth wheel with them on there.i'd bet you could get the counter weights to weigh 2000-3000lbs which would ballance things out nicely

 

[ah1955]

http://www.demount.com/
Hope this link works. This is what I think the general idea you would try for only with a shorten deuce bed and a king pin to enter the jaw of your fith wheel.

 

[73m819]

i think a bed on the 8x8 tractor would ruin the look, hidden weights between the frame would be the trick

 

[ah1955]

i think a bed on the 8x8 tractor would ruin the look, hidden weights between the frame would be the trick

That would be the advantage of some sort of self contained removeable set up.
You would be able to use it only when needed, but then pull it off and be back to the origanal look and use.
I agree that what ever you would do you would not want to change anything that would be a permanet mod. that would change the orignal look.

 

[73m819]

i believe CT wants to put weight on the rear to make the truck ride better and level out the truck, if he never pulls a trailer, he could leave the hidden between the frame weights in place to accomplish this ,and still be a tractor, in he decides to pull a trailer then use the crane to pull the weights

 

[cranetruck]

Actually, my original question pertains to the 6x6 tractors (after seeing pictures of oilcan's at the rally), although it may help my truck too.
The 8x8 should do okay with the two front axles and the 16 inch wide tires, a little more offroading will tell.
The original m656 bed and the xm757 5th wheel can easily be swapped, since they are all bolt-on, no rivets, so that's an option (if my budget permitted). There is very little difference in weight between the dromedary platform, 5th wheel and the aluminum bed, so an empty m656 would have the same problem..or not..

 

[oilcan]

To be honest, most of my tire spinning was because I threw it into 3-Hi and blipped the throttle on the flat spots. It's a decent way to clean out the tires (a little) and it can be quite impressive to watch.
I did look out the back window pretty often and saw the tires were moving slightly faster than ground speed in normal trail conditions.


Oooh, a thought! What about one of those heavy plates the road crews put out when they dig a hole in the street. Those mutha's are heavy, but wouldn't take up all that much room. Stick a kingpin on it and cut the plate to the size/shape/weight you want. Maybe add a few tiedown points to keep it from spinning and flopping around... Double the thickness if you want it really heavy.

 

[tm america]

cranetruck looks like you need to get an expandible body for your truck since they were like 10000lbs heavier .and i havent even seen any pics of one in that configeration..i was behind oilcans truck several times at haspin looked to be going pretty straight most of the time unlike the rest of us.with the exception of the m109s .he had enough traction to rip my bumper off

 

[oilcan]

Guess I shoulda leaned on ya' a little harder about being pulled out backwards...
How many bolts were actually in that bumper, anyway?



/hijack off

 

[cranetruck]

cranetruck looks like you need to get an expandible body for your truck since they were like 10000lbs heavier .and i havent even seen any pics of one in that configeration..i was behind oilcans truck several times at haspin looked to be going pretty straight most of the time unlike the rest of us.with the exception of the m109s .he had enough traction to rip my bumper off

Mike Pop found this somewhere in Colorado, it's one of very few units built (less than 20, I believe). It's the xm791 with a wind deflector added on, which was not standard.

 

[Opie]

It's the xm791 with a wind deflector added on, which was not standard.

Aaaaaaaa! Concessions to AERODYNAMICS? Heresy!

 

[Ferroequinologist]

plus putting more weight on the back will make the truck way harder to steer off road .by making the rears have more traction it will try to push the fronts.think of your truck as a front wheel drive car rather than a rear wheel car.you want to put the weight on the steer tires since they have enough floation to keep from digging so as long as you arent dragging the diffs .the more weight you can put on the front the better you will be able to steer off road .the only ill effect i see is when on road the drive tires dont have much weight on them so its kind of a trade off you get great off road for less than prefect on road .

I agree, my 109 would go sideways, with the weight of the box, the rears wanted to keep going straight.

George, why do you keep saying 109*s*? There were 4 at Haspin, but only ONE hit the trails!

One thing you could do Bjorn is mount a water tank of some sort right in front of the 5th wheel. Attach some places to strap it down so it won't move off road, and fill it to the brim, so no sloshing. You could even get a poly tank, so that two people (or even one) could get it on and off. That way, your not lugging all that extra weight around on the way to or from a rally. A tote or two would work excellent, they can be move around easy, and at 275gal each X 8lbs/gal = 2200lbs a tote.

Just get there, put the hose in a pond/lake/stream/jerks pool and fill it up. I've got a fire pump and hoses, I'm going to bring it from now on. Strech's sump pump and pressure washer were great, but not really good for the shear time it takes to clean a truck off. It didn't help that the sump pump died...

 

[cranetruck]

Here is a precedent for loading the vehicle for traction (posted by Jez (England)).