ted_pulliam

I notice that with the granny 1st my truck seems to really be able to climb at steep angles. It is running open differentials front and rear. Does this truck have a better off-road capability than say, an automatic, and is this due to the built in crawl-ratio that the granny gear provides?
I have had 2 12 valve trucks, both '97s with the automatic tranny before this one, and one was a 2500 with a rear limited slip and the other was a 3500 with (I believe) no limited slip. The 3500 was awful for 4 wheeling, but the 2500 seemed pretty good.
I'm trying to compare my current truck with the '97 2500 with the rear ls and I can't decide which is a better off-roader. What do you guys think?

Thanks for any advice,

Ted

PaulDaisy

I think that a 3/4 ton diesel is not an optimal off road vehicle no matter what simply because of the weight. Not that this should stop us from taking them off road, just that when my truck begins to slide it is harder to stop than a light jeep for example.
In my opinion manual transmission is far superior to the auto in off road conditions, not just because of the low gear but because of the control it provides, going downhill, or rocking when stuck. I would not have an auto in a vehicle I intended to take off the pavement or tow with.
Open differentials will not be so good in snow or mud; I would prefer a locker myself but those are expensive and labor intensive to put in. I have a LSD in the rear but not much need for it in CO, there is mostly rocks here for off road.

jefe4x4

Ted,
The NV-5600 has a 5.63:1 first gear. In low range your final drive with 3.54 gears gives a pretty good 54:1 reduction in low/low. In contrast to the former poster, I think an automatic is best in off-road situations, especially in rocks. With the defacto gear reduction built in because of the torque converter slip (about 2:1) you can oooze over rocks, with one foot on the gas and one on the brake.
You do want to keep an eye on the trannie temp, however, as heat is what kills an auto. With the systemic idle increase with the cummins below 600 rpm, it's hard to control the idle speed when just creeping with the NV-5600.
Still, I've gotten used to it. And, no question, the NV-5600 will outlast many automatic trannies.
I really like my Power Loc LSD. It's preloaded cone shaped clutches really grab, making the break off point very high. The big problem for you is the 1000 lb. engine over the FRONT wheels. This would be a good place to have an ARB, electric or mechanical locking differential. This would require changing the outer axles from flanged to free wheeling/internal hub style. This is in my future.
I know some folks who have been very successful off-roading a Dodge Cummins. I'm not talking speed, but a bulldozer style. It just keeps on coming at you.
regards, as always, jefe

cLAYH

I agree with the above.

I've built a number of different wheelers over the years and weight is key. The lighter you are the better off you are. Also where I am short wheel base and manvouverability halps out a lot as well.

Finnally on autos vs sticks I converted one from auto to stick and another from stick to auto so I got to compare auto vs stick in very similar situations. In each case I prefered the auto. It lets you feather over obstacles vs bumping over them. You can leave it running in park on a steep hill and auto will outclimb sticks because of the TQ and its ability to downshift without losing speed. I find its easier on the drivetrain as well and automatic lockers tend to have better street manners when behind an automatic tranny.

Sticks are stronger boxs, can limp home with water in them, don't overheat, and hold better on a downhill assent. Also less likey to get a hole in the pan or sprng a leak from a cooler or line. Don't get mud in the clutch though or you'll be sorry....

The auto vs stick argument is ancient and you will find diehards on both sides, pick what you like and go with that, whatever makes you happy.

For me I found I was MUCH happier wheeling a Jeep and using the truck to drag it back and forth to the trail.

PaulDaisy

While I personally prefer manual, I have zero problems with others liking autos. To me, uphill is never an issue, I usually go slowly and don't downshift. Downhill, is where I need control, and auto just doesn't do it for me. But this is just MHO.
Another thing that I dislike is the stiffness. When my wife moved into my friend's Jeep in the middle of the trail to get softer ride, it tells you something. The suspension on a 3/4 ton truck is so stiff, it beats me up on a rocky trail. But I have too many vehicles and don't want to add a Jeep, so for the limited amount of off road that I do, my truck will work.

ridofpwrstroke

I had a 2002 2500 with arb in the dana 80 and the eaton e-locker in the dana 60. I had to change the axle shafts because they were 32 spline and the eaton was 30. I also regeared at that time. The 5600 was great and I preferred it everywhere except the mud. I had enough power with the twins that I could get wheel speed if I slipped the cluch in third to build boost in mud, but an auto is my preference in mud (which is why my new off road rig is an auto). If there wasnt much mud, manual is my preference for the crawl ratio.

SIXSLUG

Depending on what kind of off roading you are doing, ie, dirt roads, trails, overland etc. is where you need to decide. I use my truck for hunting and fishing but mostly stay on logging roads or fields. It crawls pretty good up the steep stuff and gets good traction with the lsd, but thats taking it easy.

If I still lived in the southwest and was out in the desert washes, I'd go shortbed 1/2 ton for the approach and departure angles and the lower weight. This way you can cook thru the flats and still get some bite for the hills. The 2500 is pretty heavy to be romping in in my opinion.

totalloser

I think the worst thing about a 3500 for going offroad is that with that heavy piece of iron sitting over the front axle it's nice to have floatation tires, but making them fit on the rear means a spacer which makes the tires stick out ridiculously.

The duals in the rear can be a blessing or a curse- they can find traction outside the ruts to pull you back out, or act as a boat anchor due to width. Were it not for the extra width, I'd say they tend to be more of the former.

But a jeep it aint! :P