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Front end acts squirrely in 4wd

831 views 6 replies 4 participants last post by  7.three 
#1 · (Edited)
I have to climb a steep, improved road on a property I work on that requires I lock the front hubs on my 01' F-350 Super Duty. I put the manual stick in 4 High and it pulls it with no problem. Once I reach a level paved road and top out and shift it out of 4wd, however, turning the wheels even slightly results in a binding hop, as if it were still in 4wd.

As soon as I get out and unlock the front hubs it stops. If the transfer case were not coming out of 4wd when it's supposed to then I wouldn't be able to unlock the hubs.
 
#2 · (Edited)
What you are describing is exactly what should happen. When you lock the front hubs, you are locking them together, essentially into one straight axle. When you engage the 4wd, you are putting power to those wheels via the front drive shaft. So even if you do not have power going to them from the transfer case, the wheels are still locked together and will create the binding hop you describe.

EDIT: So I experienced the same thing and talking with a few friends led me to believe this explanation was correct. So of course, when told I was wrong on here, I did some actual research to prove my point. And I didn't. Because I was wrong. My apologies for the misinformation. I don't know what would cause it to take a while for the 4x4 to disengage so that you don't experience the wheel hop, same as I do. I would venture to say that it is due to pressure on the gears and needing time/backing up to fully disengage, but I don't want to suggest that is fact. It's merely an assumption. Whatever the case, I was completely incorrect in suggesting that it was due to the axle being locked in to "one straight axle" when the hubs are locked.
 
#4 · (Edited)
What you are describing is exactly what should happen. When you lock the front hubs, you are locking them together, essentially into one straight axle. When you engage the 4wd, you are putting power to those wheels via the front drive shaft. So even if you do not have power going to them from the transfer case, the wheels are still locked together and will create the binding hop you describe.
I know, but you can drive on pavement with front hubs locked but out of 4wd, shifting on the fly so to speak, when you need to without experiencing the lurching and noise I experience.

The only other time I've ever experienced the hop is when cutting the wheels sharply in a parking lot with the hubs engaged but in 2wd, which is normal, but it still isn't as severe as what I'm experiencing topping out on the hill.
It sounds and feels like a tire is rubbing hard somewhere but it's not...I don't think. I'm running 285/75/16's on stock rims and don't have any rubbing issues when in 2wd on level surfaces.

I do have a right ball joint that has play in it and needs replacing and am wondering if that is creating the bind.
 
#3 ·
No, the front axle is not locked together unless you put a locker in there. The front has an open diff, and other than maybe a bit more vibration than normal with the hubs locked, it should steer fine. Engage the transfer case though, and the front and rear axles are locked together and you will get wheel hop going around corners when you have decent traction.

My truck doesn't really behave any differently with the front hubs engaged but the transfer case in 2WD. It sure does on pavement in 4WD though, or good packed gravel.

I would suspect that your transfer case wasn't completely out of 4WD.
 
#6 ·
Sounds like the t-case is not releasing. I can leave my hubs locked and drive 60mph down the highway with no issues. If you unlock the hubs and put the t-case in 2H can you spin the front shaft by hand?
 
#7 ·
Not sure. I will check and see if I can turn it. I've got over 350k on the truck and 99.5% have been highway miles. I hardly ever use 4wd but the project I'm working on requires crossing a deep ravine and creek crossing. The first time I crossed it I needed my 4wd which was the first time I've used it in maybe a year. The transfer didn't go in immediately as it normally would as the rear tires spun briefly. I let off the pedal and then tried it again and I had 4wd and everything was normal.
If it's late going in then it might be late coming out.
 
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