Hi all,

We use my dad's 1999 Ram 1500 4x4, regular cab, 8' bed, sorry I don't know engine size for towing our boat short distances and plowing the driveway at my mom's and our house (dad is deceased) as well as general running around when needed. I noticed this issue 2 years ago but now I just got stuck in mom's driveway and I want to turn to the experts to see what you all think.

2 years ago, I felt like the 4wd wasn't engaged (4H) when it said on the dash that it was. Took it to the dealer, they said there was no issue. We get a lot of drifting in our driveways that you can't always keep up with (or if it's REALLY bad, I just get in the backhoe and deal with it that way). Last year, we put a few hundred pounds of ballast in bins in the back of the bed and secured it down. This year, haven't put the ballast in yet. The storm on the 26th, I plowed with no issue, 4H in her driveway and 4L in ours because I got a bit behind and wanted to run a pass in 4L just to get it opened then went to 4H.

Storm yesterday, 4H no issue. Lots of wind here today, drifting in the driveway. Took the truck, went to 4H, dash light on...... not so much. I was pushing not much at all and it got stuck. Ok fine, go in reverse, back wheels just spinning. Tried forward and back again but didn't want to overheat the trans so I stopped and got out and swore a whole lot. My husband came up, started shoveling a bit, I got back in and he said you're not in 4WD. I said "WTH yes I am" and that's when he said the front wheels weren't moving.

And therein lies my question. As I understand it, the light on the dash is the list thing in the line of what happens when you shift the transfer case so that if the vacuum was working and the switch was getting pushed, then the dash light comes on. All threads I searched on seem to be where they light isn't coming on for people. In my case, the light is on but I'm not locking the front. This isn't something I'll work on myself but I wanted to see if this made any sense to anyone. What I did tonite was go from 4H to 2H, go forward and back a bit, then go back to 4H and sure enough, I got right out of the mess I was in (after my butt end already slid around causing some grass reconstruction to be needed in spring, cripes).

Any idea what would cause the 4wd light to be on but not actually in? During the spring/summer/fall, we never engage 4WD (boat ramp not steep enough or slick enough to need it and boat's pretty light) but I'm wondering if I shouldn't take the thing in the field once / month or something and go into and out of at least 4H.

thanks in advance!

 

welcome to df.

run it into a snowbank so the rear wheels will spin. put it in 4wd and CAREFULLY look under the truck and see if the front drive shaft is turning or not. put a big piece of duct tape around it so its visible.

the dash light is tied in with the CAD front axle lockup. generally, the light is a good indication that the front axle halves are connecting up, but if it is, and at least one front wheel isn't turning, then verify t-case is engaging front drive shaft.

CAD stuff.
http://dodgeram.org/tech/repair/4X4/4x4_engagment.htm

 

Forgive me if I'm a bit nervous to intentionally put it into a snow bank (while I have the backhoe to get it out if need be, I was hoping not to need it LOL!). I've read that if you jack up the front passenger wheel you shouldn't be able to turn the wheel by hand if it's in 4WD, could I do that test instead? I'm guess have it in 4H with the transmission in Park, jack up and turn the wheel?

 

i didn't mean to do it hard. just duplicate your stuck condition with rear wheels on ice.

turning the passenger side wheel will verify the CAD is engaged and the passenger side axle is locked, but it won't verify the t-case is turning the drive shaft.

 

Ok thanks. I'm going to try it tomorrow if I get a chance between a half day of work and digging out the barn and pushing back snow banks with the backhoe. That link you gave me has at least helped me understand how the system is supposed to work. I know you can go into 4H at speed but I generally do it in park before I get moving when I know I'll need it and I'm wondering if maybe that's not good because things can't sync up like they should. Going from 4H to 4L I'm rolling about 2 or 3mph before I put the trans in N and the transfer case to 4L (same to get out) because that's how my father did it but maybe going from 2H to 4H at a stand still is part of my issue. Not sure, just a theory. I think I'd like to go back to locking hubs at this point LOL!

 

One other question I don't quite get... why the need for a split front axle at all? If the transfer case engages the front drive shaft, why not just have that and be done with it vs also having the front axle split? Is that because even in 2WD if the front axle wasn't split, you'd buck when making turns because the one side has to go further than the other on a turn?

 

there is no difference in shifting to 4HI in park or drive. same result, no harm either way. you can make that shift at speed because that t-case shift has synchronizers.

the 2LO shift requires more patience. you are doing it correctly. you can also do it with engine off, and if you ever get hung up in neutral and cannot complete the shift, then turning engine off is the easiest way to finish it. same result.

if the vacuum CAD ever seriously messes up and needs replacing, and if this is just a 4wd beater truck, you could consider eliminating the disconnect and permanently blocking the shift collar in the engaged position. this would be sort of close to locking hubs that were always locked.

first things first - verify the drive train from its source (t-case) to the wheels. start with front drive shaft.

 

the 2 piece axle is the equivalent to the locking hubs, so you can operate in 2wd more efficiently. as in - turning a lot less objects, less wear and tear, and more mpg.

in 2wd with front axle disconnected. passenger front is free wheeling. drivers front is turning the spider gears and intermediate shaft. ring gear, pinion, and front drive shaft is not turning.

this is an mpg improvement over a permanently locked front axle.
its a convenience improvement over the old locking hubs, where you had to get out in the mud to lock them.

axle lock will not cause steering bucking because the spider gears will balance it out. the bucking is driveline bind between rear and front diff, caused by lack of center differential. our trucks are considered part time 4wd because they have no center differential. a more modern full time/all wheel drive vehicle has a np247? t-case with center differential.

 

Thanks for the added info and explanation. Always good to learn things even if I end up having to go to the mechanic. We'll see what we can see tomorrow once I put some tape on the front drive shaft (my husband just said he'll drive the truck and I can lay on the ground and watch LOL!). Hopefully we'll be able to do it tomorrow if all else goes well with snow clearing but I'll report back. I have this feeling this is an odd intermittent issue since it finally did go into 4H and has done so in the past.

 

if you have a level place to work, the best and safest way to work on it is to put it up on 4 jack stands and operate the truck. this way you can run the engine, have vacuum to the cad, make your shifts and observe the results safely. you can then kill the engine and rotate things by hand to see what's what.

sounds like you have too much snow...