M925 A2 very disappointed in ability

[Fastfunco]

very disappointed in this beast-- Everything is brand new- runs perfect - and we decided yesterday was the day to explore a route we need to get thru if our roads are ever closed-- Offroad she was a champ- Im sure nothing except another one of these could keep up - goes straight thru anything- We came into this canyon that has a steep sand trail at the end that we must navigate up and over or we are finished- We pushed the Sand option for tires - dropped it into low range flipped the front locker and proceeded up-- got about 20 ft - 1/4 way up - she started hopping - and dug herself in!!!!!

I tried 2 more times - high range- low range - nothing -- sand too soft - but i would have bet the farm she would have motored right up this hill!!

This hill is the only way out and this truck is worthless for us if it can not make it -- --- ANY SUGGESTIONS- will good year tires work better in sand? increase horse power ?? is this truck true 6 wheel drive ???

 

[Recovry4x4]

Power isn't the answer. Add weight to the aft portion of the bed and dump some (lots) of tire pressure. That truck empty has no suspension and will beat the snot out of itself.

 

[HASSON1911]

Ditto what recovery said, also it is 6x6 but unless its a marine truck you dont have lockers. If you did then that truck would quite literally be unstoppable! Also, what kind of grade are you going up, it wasnt exactly meant for hill climbs.

 

[markmontana]

Where's the picture of the truck stuck in the sand? Did I miss it?

 

[TacticalDoc]

lockers?
had mine in sand and mud but have rear lockers... no problem
never took it up a big sand hill
in general wider tires are better for sand.
I think the mich 385 tires and 1600 tires are wider than the 1400s I have


<------ m923 with lockers

 

[AZDeuce]

It concerns me that you stated she was hopping, generally when a deuce or 5-ton starts hopping in the sand, that means your front wheel drive is not engaged and/or working properly. Had it happen on a M52A2, and a early gas M35. On the M52A2 the air pressure valves were dirty and sticking, on the M35 the shaft between the transmission and transfercase had come apart. I'd check to make sure your front wheel drive is engaging properly.

 

[HASSON1911]

It concerns me that you stated she was hopping, generally when a deuce or 5-ton starts hopping in the sand, that means your front wheel drive is not engaged and/or working properly. Had it happen on a M52A2, and a early gas M35. On the M52A2 the air pressure valves were dirty and sticking, on the M35 the shaft between the transmission and transfercase had come apart. I'd check to make sure your front wheel drive is engaging properly.

Not always the case. But a possibility!

http://www.youtube.com/watch?v=p4fvB3-8jUA

A couple things to note about this video too, Just because your hoping doesn't mean your stuck, it also doesn't mean to keep hoping till you bury yourself(because now your fun turned into a recovery, which can still be fun!). This guy had commented he had 4000 gal of water(16 ton in water), weight isn't everything but it does help, what it comes down to is the knowledge to know how to operate the vehicle in a manner proper for the road condition.

 

[Suprman]

Fine sand is mean stuff. I was stationed in 29 palms for some time I saw firsthand just about everything getting stuck at one time or another. If the sand is fine and deep and you just cant get good traction the only cure is to have a vehicle on top of the hill pull or winch you up. The truck weighs 21000 pounds that's a lot of weight to be chugging up a hill to begin with, add in sand and the truck will drag itself down faster than the wheels can pull it up. That's why people use lightweight sandrails with big tires out in the desert. In the water truck vid the ground looks wet but packed it appears to be a well used route. I could be wrong though.

 

[TacticalDoc]

first thing I noticed is that the sand isn't that fine
second thing I noticed is that they don't have lockers and at least one of the rear wheels would stop
if they had lockers they would have made it up much easier

 

[VPed]

Agreed, fine sand is mean stuff - and disagree, hopping usually means your front axle is not engaged. I hop plenty and know my front drive is working. Easy enough to check though.

I would suggest trying emergency drive mode on the CTIS for the hill (and only the hill). If that is not enough, 16x20's might do but is a pricey proposition to find out if it is enough of a solution. One of the things I have thought of doing to my truck is to add shocks to the rear axles. That hopping is nasty. I figure that if I reduce or eliminate the hop, I can increase the performance. My experience is with a deuce on 395's which is better than a 5 ton for the sand. I am working on getting a 5 ton though, so soon I will be trying the sand thing with that as well. We have lots of sand around here.

 

[Fastfunco]

Fine sand is mean stuff. I was stationed in 29 palms for some time I saw firsthand just about everything getting stuck at one time or another. If the sand is fine and deep and you just cant get good traction the only cure is to have a vehicle on top of the hill pull or winch you up. The truck weighs 21000 pounds that's a lot of weight to be chugging up a hill to begin with, add in sand and the truck will drag itself down faster than the wheels can pull it up. That's why people use lightweight sandrails with big tires out in the desert. In the water truck vid the ground looks wet but packed it appears to be a well used route. I could be wrong though.

this hill is a little steeper than the video here-- the sand is soft under a gravel rocky top surface-- front tire drivers side was pulling when she stopped and just started hopping like any 4 x 4 does when its met its match-- I have had 4x4 s all my life -- usually when there is a locker in front this problem goes away-- I thought this truck would be !!
how much weight do I add to the back?? any ideas on what would be a good thing to use for the weight? sandbags maybe?? can i get a locker for the front of this truck - if so -- where ??
thanks for all the advice you guys -- i can always count on this site!! next try i will take a video--
but first-- locker and some weight

 

[HASSON1911]

first thing I noticed is that the sand isn't that fine
second thing I noticed is that they don't have lockers and at least one of the rear wheels would stop
if they had lockers they would have made it up much easier

No doubt lockers make a difficult drive, easy for even the novice of drivers. Those water tenders had some experience of some sort, once you start hopping stop. Your not going anywhere but down, stop back up and try again. Same is true for mud, snow, spinning tires...etc Most vehicles will do what you ask and more....if you know how to operate them. Just remember there is a difference between operators and drivers.

 

[Recovry4x4]

In regards to weight, balance is what you seek. The deuces and 5 tons are very nose heavy. Check out the pics from the GA Rally. Any 6x6 you see stuck is usually nose down. Considering the weight of a 5 ton, I would look to add about a ton at the back end of the bed right at the tailgate. 2000# aft will unload some of the weight concentrated on the front axle and get you a little suspension action in the rear. I think sand bags would be a good choice to dial it in.

The 1600x20 tires were mentioned. Don't sell short the little 395 tires either. You loose 3" of height but pick it up in width. The Goodyear MT/V tires seem like it would be a better design for sand than the Michelins. Don't give up quite yet, with just a little tuning and experimetation, I think your truck could be the "Can do" truck you need.

 

[FASTNOVA]

 

[TacticalDoc]

consider a 100 gal transfer tank in the back. it adds 7 to 800 lbs. also put your tow bars back there. you can mount them using any spare feet you may have. I'm also putting a gang box in the back for all my tools and spare parts. Also another spare tire and generator. Better to have things you may need than sand bags. The most important thing would be lockers followed by wider tires. And you can let the air out and drop the PSI to about 50.

I also have chains too but that's for mud and snow...not sand.

 

[The King Machine]

It's not the truck

Air down..........a lot

Open diffs or not.

My 395's on my deuce in loose terrain are set at 10-15 psi.

For sand and snow this is critical. I don't know the 5 tons however

 

[Coffey1]

If you still have problems and need to go that get some flat ramp to put on ground to drive on

 

[TacticalDoc]

It's not the truck

Air down..........a lot

Open diffs or not.

My 395's on my deuce in loose terrain are set at 10-15 psi.

For sand and snow this is critical. I don't know the 5 tons however

I believe its 50 to 90 PSI for my 1400s on my M923. I'd put it down to 50 in the sand and run them at 70 normally. I also have a Viair 450P that I can use to fill it up.

 

[TacticalDoc]

If you still have problems and need to go that get some flat ramp to put on ground to drive on

I was going to say this too...you can get a traction mat but its going to be a pain if you have to move it every few feet

 

[TacticalDoc]

also you may not want to add much weight in the back when going in fine sand

in sand you want to float ... ie wider tires, less aggressive tires and less tire pressure
in mud and ice you want to sink where you can grip firm ground ... ie thinner tires, more aggressive tires (meaning bigger lugs) and more tire pressure

chains for mud and ice