Front end steering "lost" in 4wd

[CJ Johansson]

OK, maybe "lost" isn't the right word, but...

Here's the situation, I've driven many different 4x4 rigs in all sorts of conditions, but this 3500 is next to worthless at trying to drive in mud or snow in 4wd.



It's OK in snow on the highway, but get anywhere near a sidehill and the front end just wants to dive down the hill no matter what you do with the wheel. For instance, this morning it was a bit muddy in my driveway (well, it's over 1/2 mile long, but) from rain which started about 3AM. I tried to turn to follow the road up a small hill but no, I just went straight. I was in 1st, low range, just above idle, so I don't think speed was a real factor. Luckily, going straight wasn't a problem, just drove through the hay field until I met the road again. Oh, the soft mud was only about 3 inches deep, then "normal" dirt, yeah, I need more gravel, but that gets spendy.



I originally thought it was the tires, the factory Michelins were more street tires than mud & snow. Now I've got Toyo M55s on the truck, they're fairly aggressive, but the same response. This gets to be a *real* pain once winter sets in.



So, any insights? Does anyone else have this experience? Is it the massive weight of the Cummins? I'd think that would help the front end with traction, plus, with my big heavy flatbed, I think the weight is kinda evened up a bit (8380lbs empty). Is there something else wrong with the front end? Something I should be doing different? At times like this I sure wish I had independent braking like on the tractor...



-cj

 

[Cooker]

How much air pressure are you running in the front tires? Just a thought.



FWIW - I don't know about your driveway, but where I work there is a large "staging area" that is sold as a rock clay when dry, and slimey as hell when it's even a little wet. Regardless of what truck you are in and what tire you have on, the trucks all will go straight in 4x4 when turning the wheels, you have to get on it a bit to get it turned around



-Ryan

 

[NVR FNSH]

Are you sure the front axle disconnect was engaging? Does it help to spin the tires & clear the built up mud?



I got back on to pavement in my Jeep after playing in the mud and even though the wheels were turned to full lock I kept going straight until the tires cleared.



Brian

 

[Morphious]

I added 200 lbs to the front end of my truck and give it hell, spinning the wheels to get where I need to go. I also have alot of weight in my tool box, another 100lbs for my gooseneck hitch.



Morph.

 

[RKohn]

The gravity that's pulling that monster motor down slope can only be countered by application of another large force... say like a heavy right foot on the go pedal. Gotta power it up to pull it thru.

 

[DarrellB]

I can't see

Got alot of rain here today and went to a freind's house were I have been cutting up some tree tops for firewood. I had to pick up my trailer and saws with the trailer behind my truck and the mess in the resently picked corn field I had the same problem. I just had to use a heavy right foot and a higher gear. But be foreworned that this causes complete and utter blackout on the windshield. My choice of tires proble doesn't help(33/12. 5 BFG MTs) but now I think I'll need a new set of wiper blades and to refill the washer tank.



On the upsid it was kind of fun, not much fun cleaning up the truck though.

Big D

 

[OILBRNR]

CJ,



I suspect the weight is the right guess.



I don't get up to my native northern AZ as often as I'd like to, but last xmas I was out with my Dad getting trees north of Flagstaff toward the Grand Canyon. Several inches of old snow was still ont the ground and was melting, causing 3-4 inches of mud underfoot. He was driving our old POS '78 Ford 2wd F250 that used to be our company delivery truck and I was trying to follow in the Ram. The Ford did have rear snow tires, but geez, I had 4WD! He went off and left me on several occasions!



I could not keep the front end out of the prior mud ruts! Just too much weight! I doubt that even with the new BFG A/Ts I have now it would have been different. I fought that b*tch every mile in and out to 89A north back to Flag. Granted, I had the Michelins on but condidtions were not *that* bad, and there is a lot of rock underfoot in this part of AZ.



If you have a 3500 with limited slip rear end, and stock highway tires, you were probably doomed to front end plow, esp. , if gravity was also playing a role.

 

[Skyjacked Ram]

I looked up the M55 tires and although they do have a some what aggressive look to them they are far from a mud tire, aspecially the type you deal with. I grew up in Alaska and found by way of trial and error that in my opinion the best tire you can have would be a true mud tire and then have the tire company sipe the heck out of it. This type tire would have the big self cleaning aggressive tread for sand, mud, snow, and the sipe cuts are what is needed on ice.

The mud would fill the M55's and once that happens your SOL, aspecially since your just barely puttin' along and remember you have that big rear end with four paws pushing you straight forward (thats their job) and with a muddy front you go straight... I have kissed many a tree in this situation.....

 

[RonaldLarson]

The first rule of off-road driving, which apparently applies to your driveway, is: when driving downhill, and experiencing rear end swingout, apply power. Gravity is your enemy, not your truck. The front end is heavier than the rear, so the rear goes skating while the front follows gravity, which is a vertical line downward. Straight downward. Get a copy of Jeeps book on offroad driving, and you will find a lot of good info. When in doubt, Power out!

Ron

 

[CJ Johansson]

Thanks, folks for all the input!

Sounds like it's partly my technique and the massive weight of the front end on this truck. My other truck, same tires, Ford F250HD with 460 gasser just doesn't do this, or not nearly as much.



I never seem to have problems with the rear, it's an open diff, some day I'll put in an ARB locker (if they ever make one for a Dana 80), maybe an ARB up front would be a good idea too. But, that wouldn't change the weight problem.



I'm fairly sure the front disconnect is working OK, I use 4wd *EVERY* day, mostly to help drive up the road to my driveway, 10+% gravel for 3 miles I can feel the front grab and the rears stop slipping around as much. I sure wish I had a solid front axle and manual hubs like the Ford, I know those work!



I guess I'll have to try the "power out" method, then maybe more aggressive tires. These aren't lasting nearly as long as I'd hoped, despite what the dealer said. I guess all these bumpy, steep, gravel roads we have here in Idaho are just hell on tires! They beat the crap outa suspensions, body parts, frames, and anything else that's not as tough as a Cummins (or a Deere, CATs do OK too, they just beat the crap outa YOU )



-cj

 

[hammersley]

It's called the dual phenomen....

In dual or tandem truck setups - you always have way to many wheels pointing straight ahead to be overcome by two little tires up front, hence the huge front wheels often used. I think the 3500's have way to skinny of a tire upfront for offroad applications, and this is largely the problem. Remeber it takes more energy to overcome the inertia of going straight ahead, and when you're in "stuff as slippry as owl poop" well you realize why they have tracked vehicles!

 

[Bad340fish]

Don't put a locker in the front if you want it to steer better!! A friend of mine had a 91 4 runner with lock rites in both the front and rear. That thing had the turning radious of a freight train in 4wd lol. Could hardly make any of the turns on the trails without dropping into 2wd.



And about the steering, I learned with my 4x4 toyota "When in doubt. . throttle out" My truck was locked in the rear and when things got really nasty(i. e. tree approaching) I floored it and stomp shifted into the next gear. USUALY shot the truck in whatever direction the front tires were pointing. You might try some really hairy mud tires on the front at least. Those are bad about throwing rocks though.

Clark