Hubs or transfer case problem?

[Dr.Doug]

1991 Explorer. 118,000 miles. Auto Hubs, Electric shift motor, Transmission, NOT TRANSFER CASE, was rebuilt last week.

Here is the problem:

I tested the 4WD, after the rebuild, to make sure that the connectors were attached etc. It engaged in 4X4 high, low etc just fine. When I turned the 4X4 off and backed up, the hubs will not disengage. I tried numerous times at various distances (forward and backward)

I checked the shift motor, on and off of the transfer case, and it rotates fine in sync with the dash button.

I manually turned the shift knob, located under the electric shift motor, to 4X4 and 2 HI. It turned without resistance.

I removed the front hubs, reinstalled them making them free to turn with the wheels off the ground.

I backed up and lifted each front wheel confirming that they were free. I then put them down and lifted the rear with a roller floor jack. In 2 WD, the shift motor disconnected from the transfer case and the transfer selector on the transfer case in 2 HI, I put the vehicle in drive. The vehicle walked forward. (The front wheels were pulling) In addition, in reverse, the front wheels pushed.

QUESTION 1: If the hubs were bad and locked on their own, would power still be coming from the transfer case? (I have had issues in past years where the hubs would not immediately unlock)

QUESTION 2: Would a reassembly of the transfer case, when the transmission was rebuilt, cause this issue?

How could I test that the front drive shaft from the transfer case is not active in both 4X4 and 2 HI without jacking the entire vehicle up?

Please advise.

Thank you, Doug

 

[mrboyle]

The only way the front should be getting power to it is if the t-case is in 4wd. It doesn't matter if the hubs are locked the front shouldn't be getting power if the t-case is in 2wd.

 

[gorilla]

My truck has the same problem with the hubs not wanting to unlock when they are supposed to. The only difference is my truck has about 230,000 miles on the auto hubs and they REALLY need replaced.
I have talked to a friend at Ford and he said that one problem I am having is the U Bolts on the front axle are worn out and the axles are not rotating currectly. Basically the axle is wabbling around and only catching the hub like half the time. Another comment that he made was almost all auto hubs from Ford are junk after approximately 50,000 miles. So there are two options that I would check out if I were you.

 

[Dr.Doug]

I replaced the hubs today with WARN manuals. The transfer case still appears to be locked in 4 WD. I confirmed that the switchon the case, under the motor, is in 2 HI.

Any idea why the transfer case would be locked in 4 HI?


Thank you, Doug

 

[Adam Berger]

I just wanted to ask something about auto hubs while we're on the subject. I noticed that when my Ex moves, the front drive shaft turns. Would this mean the hubs are locked? My Ex has done 85,000km (53000miles). If this is the case and they are locked should I replace them? Would this cause bad fuel econemy? Is there any aftermarket auto hubs you can buy?

 

[gorilla]

Yes, I do believe that if your front drive shaft is turning that means your transfer case is engaged. And if that is the case then, yes it would cause lower gas mileage.

The only thing I have really heard about the transfer case not locking or unlocking is a failure in the electric motor. I know mine needs pulled out and cleaned because I get a lot of clicking when I push the 4x4 buttons on the dash. Good choice going with the Warn manuals!! Good luck!

 

[Dr.Doug]

Adam,

The 1999 is a different bear from the 1991-1994. Sorry that I can't help.

The 1991-1994 front drive shaft shoud not move unless in 4X4.

Doug

 

[Robert]

Adam Berger - The reason your front driveshaft is turning is because your '99 does not have hubs. Your front wheels are connected directly to your front axles via a CV joint. It does not disconnect. When your wheel spins, your axle spins, when your axle spins, your differential gears spin, when your differential gears spin, your driveshaft spins. Your driveshaft is disconnected at the transfer case. It is normal. If your driveshaft isn't turning on your '99 when you are driving something is broken.

 

[gorilla]

Good point! I overlooked the fact that Berger's is a 99. Opps...

 

[Ray Lobato]

Originally posted by Dr.Doug
I replaced the hubs today with WARN manuals. The transfer case still appears to be locked in 4 WD. I confirmed that the switchon the case, under the motor, is in 2 HI.

Any idea why the transfer case would be locked in 4 HI?


Thank you, Doug

I don't know if the pre 95 T-cases are like the newer ones but here's my take on this.
You have a 2speed T-case, that means you have a hi speed and a lo speed. what makes the front drive is a clutch pack in the T-case. some times this clutch pack will get stuck and keep the front engaged, this is where the old hit it with a BFH comes into play. This will loosen up the clutches and it will disengage the front drive. I don't know if pre 95's have this clutch pack, but I know that the 95+ models have this. It is part of the control trac system. The one thing I do know is that your T-case is either in hi or lo. Note: there is a neutral position on your T-case. It was a towing option that Ford charged $50.00 to install a switch that would put the T-case into this position for towing your truck. I don't know if they still offer this option.

 

[mercury]

I have a 91 and had the same problem. To find out if it is the hubs or the transfer case raise all four tires off the ground. Put the trans in netual then turn the rear drive shaft by hand, if the front drive shaft turns with it, it is stuck in 4X4. Make sure you go to a good trans shop. The shop that rebuilt mine had to go threw it twice to get it to work right and I'm still not all that happy with the way it unlocks 4X4. Also with the tires off the ground when you turn the driveshaft backward a little you can see and feel the hubs unlock, then turn the drive shaft forward and you will see the hubs lock in.