As FORDF250HDXLT said, that's not right. So to make sure I understand what's going on:

• you've got the t.case in 2WD, and both front wheels off the ground
• When you turn the drive shaft it turns both sides of the axle a little, then the left one stops before the left tire spins
• The right tire spins a little, then it stops and you can't turn the driveshaft any more
• When you try to turn the driveshaft the other way it's pretty stuck at first
• Once it moves the other way you repeat the scenario

I'm having a hard time thinking of one thing wrong that would be likely to cause this. So bear with me as I think (virtually) out loud.

It might be easiest to diagnose this if you first take the front driveshaft out. That's not too hard, it's just removing the two U-bolts at each end. Be careful not to drop the caps off that will be loose once you get the U-bolts off, all the needle bearing will fall on the ground. And when you go to reinstall it be careful again, and don't tighten the U-bolts to tight. You can squeeze the caps down and wipe out the needle bearings.

Once you get the driveshaft out, pull the caps off (carefully, over a clean surface to catch any needles that drop out). How do those bearings look? And try to move the U-joint cross in both ends of the driveshaft. Those should move pretty freely.

Now crawl back under the truck and try to turn the yoke on the front of the t.case. It should turn pretty freely in both directions.

Now try to turn the yoke on the front differential. If you haven't found any other problems up to this point this should do the same as when you turned the driveshaft before.

When you get to the point where you can't turn the yoke any farther, try turning the front tires. I'm having too much trouble sorting through all of the possibilities here in my head, so I'll just say that if you turn the tire farther in the direction it was already turning the hub should stay locked and it should turn the axle. If you turn the tire the opposite direction it should unlock the hub and the tire should then turn freely (in either direction) without turning the axle. Play around with this on both sides and see if you can figure out what's binding.

Another thing to try would be to remove the auto hubs. Now can you turn the yoke on the differential without it binding? If you can, then it's something in both wheel bearings or brakes. If not, then it's in the diff or both axle U-joints.

If it's in the t.case you're looking at a tear down there.

If it's U-joints in the front axle, that's your best case. Just replace them. You might want to put new ones in anyway, they aren't very expensive and learning to replace U-joints is good to do

If it's wheel bearings or brakes you probably will know what to do (but it doesn't sound like that since you can turn both sides when the hubs are unlocked).

Probably the most likely thing in the front axle would be U-joints. Those aren't much worse to replace than the driveshaft joints, but getting the axles out requires taking the spindles off which is rarely easy.

That's probably enough of my rambling. See if you can narrow it down farther and let us know, then we can give more specific thoughts.

 

Obviously there are a variety of opinions on this, many of them very strongly held. As noted, I am not a big fan of auto hubs (I immediately took them off the only vehicle I've ever had that came with them).

A big reason that I don't like them is that I don't like very much that's automatic on my vehicles. I like automatic spark advance (I've driven a 1929 Model a that didn't have it). Automatic chokes are nice when they work right. And I don't mind having turn signals that shut off when you straighten the wheel. But other than those things I really prefer to have the control myself. Auto hubs are like that. I want to know when theyare locked and when they are unlocked.

Another big reason I don't like auto hubs is how they work. As I said earlier in this thread, every time you reverse direction in 4WD they unlock and then relock. If you spin the back tires at all as that happens you hammer the hubs. I don't want to need to worry about that.

My final reason, and the least important to me, is reliability. Auto hubs are definitly more prone to failure that manual hubs, either by sticking engaged, or by breaking and then not engaging. But if they are maintained well the sticking isn't much of a problem, and if you are careful with them (see above) the breakage isn't much of a problem.

For me the downsides far outweigh the upside of the convenience. But my wife's Explorer had auto hubs. We never had any trouble with them in 100K miles, and if we had I would have put autos back on it. For some the convenience is worth the risk.

 

In response to the first part:

Vehicle in 2wd. I spin the driveshaft and confirm that both axles are spinning just fine. I feel the hubs lock and the right wheel starts to spin. It spins maybe 1-2 revolutions and stops. Its hard, but i can break it loose and either turn it further the same direction or back in the opposite direction. Again, it will turn 1-2 revolutions and stop. Backing up a bit, when i say i have to "break it loose," i will bump it with the bottom of my fist and turn on it til it breaks loose and spins again.

What i am gathering from both of you is...i should be able to spin the driveshaft all day long. Is this correct?

I will get underneath and start tearing into it and inspecting things. The only thing i dont understand is how that could be the howling noise i hear while riding. If i understand correcty, none of those front end drivetrain components should be engaged or spinning while im riding in 2wd, correct?

Come to think of it, i am also getting wump wump wump noise/sensation when i am rolling to a stop. The "wump wump wump" i am hearing and feeling is definitely directly related to the speed of the front wheels. It seems like it happens once every rotation of the wheel.

 

Yes, you should be able to keep turning the driveshaft until you are bored with it. It shouldn't get to a point where it won't turn.

You say the right tire starts to spin and then it spins 1 - 2 revs before getting stuck. Is that the tire going 1 - 2 revs or the driveshaft going 1 - 2 revs?

If it's the tire going that far I'm really confused, but if it's the driveshaft, then I'm thinking it sounds like you've got warped rotors and your brakes are dragging harder in one spot. If that was the case you would be able to turn the driveshaft (and tires) until you got to the tight spot, but then you might not have a good enough grip in the driveshaft to push it through. This would also fit with the "wump wump" as you are stopping.

If that is the case you ought to be able to feel it when you spin the tires (hubs unlocked) too. But since the tire is so much bigger in diameter you might be able to turn it through the tight spot rather than getting stuck like when you are turning the driveshaft.

Or maybe only your right brake is giving the on-off drag and your left is always dragging a little more. It could be that the amount of drag isn't really enough to be that big of a problem, but it's enough that you can't drive through it turning the driveshaft by hand.

Keep going with it, you'll get it figured out pretty soon.

 

Thanks a bunch man. In gona get underneath there tomorrow and spend some time. I will also confirm how many revolutions the wheels are turning and how many the driveshaft is turning.

 

Well I have good news fellas. I hope it's good news anyway. Following Nothing Special's advice to rule out warped rotors, I removed my brake calipers and pads. I also removed the auto hubs since I will be replacing them with manuals. Now I can spin the driveshaft all day long. The axles and u-joints spin just fine too. The only thing I noticed is that i can spin the driveshaft with one hand, grab the axle with the other hand and I can keep the axle from spinning, while the driveshaft just keeps on spinning. Is this normal?

 

So the problem isn't in your t.case, driveshaft or diff. It's good to rule out the t.case and diff! So it sounds like most likely brakes, or possibly wheel bearings.

I'm guessing that when you are stopping the axle and continuing to spin the drive shaft that you are only stopping one end of the axle. If that's the case then yes, it's normal. Your diff is doing what open diffs do, sending all of the power to the side that doesn't have any "traction." The other end of the axle will be spinning twice as fast.

 

When you say "one end" of the axle, do you mean one side? I mean I can hold the right axle while spinning the driveshaft and only the left axle will spin. Just the same, I can hold the left and only the right will spin. I just didn't know that I would be able to stop the axle from spinning since it is connected to the driveshaft. Is this indeed normal?

 

With an open diff that is normal.

Good news as brakes are a lot cheaper than a diff or transfer case.

 

I know man. Thanks

 

Hey fellas. I have an update. The humming noise is completely gone!! Thanks to all of you. However, I still have the wump wump wump noise/sensation as I am rolling to a stop. Just to update you on exactly what I replaced, I did new rotors, pads, inner and outer wheel bearings, and mile marker manual hubs. I thought it was maybe a warped rotor, but it is still there after the rotor swap. It is more of a sensation than a noise. It seems to sync with the turning of the tires...I can hear/feel one thump for each revolution of the tire. I'm starting to think its one of the front tires, but I wanted to get y'all's opinion. I can't find anything stuck in the tread anywhere. I may switch the fronts to the rear and see if I can still feel it. One more thing...I can feel it whether I'm on the brake or not. Any feedback fellas?