4WD / Transfer case woes

[scrutton]

1996 Ford Explorer Sport 4WD control-trac.

I appear to be experiencing slippage in the transfer case area. The Haynes manual refers to an 'electrical clutch (that) activate(s) the front driveshaft depending upon road condition'. I think that this 'clutch' may be slipping...

I think that I caused this problem. I ran the vehicle for about the period of one month in 4WD with the rear driveshaft removed, while I was changing the U-joints over. It's never seemed the same since. Towards the end of that month, the slippage was so bad, it wouldn't actually move forward any in 4WD (with the rear driveshaft out). In fact, it would appear to 'slip out of 4WD' - the 4WD lights would go out, and it seemed to shift into 2WD under acceleration. I also had big problems (slippage - lack of power) ascending hills earlier in the month when the transfer case appeared to be having a good day.

I have since finished the U-joint project and reinstalled the rear driveshaft. So far, I've had the transfer case fluid changed, and there was no difference in behaviour.
Obviously things are better since reinstalling the rear driveshaft, but slippage still occurs. Basically now, I can feel it start to slip, then it will catch. This equates to a slight hesitation, but otherwise normal behaviour.

In addition, after running the vehicle in 4WD LOW for about 15 minutes, the 4WD LOW, and 4WD lights on the console go out, but the car still appears to be in 4WD. This seems similar to earlier noted behaviour with the front driveshaft removed.

Anyhow, I wonder where to go from here, is a transfer case rebuild worth exploring? Can the 'electronic clutch' (whatever this is?), that is inside the transfer case,
be rebuilt? Should I look at replacing the transfer case with something else...? Should I go to Ford and confess what I've been doing to this vehicle..? Any tips on why it might be dropping out of 4WD when under acceleration, or why the lights are going out..?

Thanks for any help,

Paul Scrutton

 

[NoBoundaries]

This is somewhat confusing to me. From my understanding, the Control Trac system cuts off above 35 mph. I don't see how you would be able to drive in that case above 35.

 

[mbryda]

I thought when you locked the truck in 4WD it stayed there no matter what the speed.

-Matt

 

[Triton46]

let me make sure I understand this...you turned your Explorer into a front wheel drive? Is that right?

 

[Robert]

Originally posted by mbryda
I thought when you locked the truck in 4WD it stayed there no matter what the speed.

-Matt

It does when you have the 4x4 High setting. The '96s have an auto setting, not a high. High will lock the front and rear driveshafts together. Auto will drive the rear wheels only until they slip.

 

[scrutton]

Originally posted by NoBoundaries
This is somewhat confusing to me. From my understanding, the Control Trac system cuts off above 35 mph. I don't see how you would be able to drive in that case above 35.

Not sure what you mean. In 4WD AUTO, the front driveshaft kicks in as and when necessary, so, it was having to kick in all the time when the rear driveshaft was removed from the vehicle.

In 4WD LO, I believe that both driveshafts (front and rear) are driven all the time.

 

[scrutton]

Originally posted by mbryda
I thought when you locked the truck in 4WD it stayed there no matter what the speed.

-Matt

Well in 4WD AUTO, it really drives in 2WD, until it notices slippage, and then it switches to 4WD by activating the front driveshaft (once it has noticed the rear wheels slipping, I think).

 

[scrutton]

Originally posted by Triton46
let me make sure I understand this...you turned your Explorer into a front wheel drive? Is that right?

Yes, this is correct!

Paul

 

[Triton46]

OK, now that, that has been established...I think you may have done some real damage to the 4X4 system. It was not meant to work as a replacement for the rear differential.

The 4X4 system is to pull you out...and it fully expects the rear wheels to be doing there part to push you out. Best thing I can suggest is to check things out piece by piece. Does the noise exist when in 2wheel drive? If not you may only have problems with your front differential. You may want to take it apart and check out the gears. If they look really worn, go to a junkyard and replace them, refill the differential and you should be ok. It could also be the autohubs, I would have them inspected as well. Good luck!

 

[Triton46]

Paul,

I just noticed youre over in Durham...and a software engineer to boot. Im a software engineer in Greensboro...small world. Were starting a Carolina Explorer Club...check out the General Exploration forum.

 

[scrutton]

Originally posted by Triton46
OK, now that, that has been established...I think you may have done some real damage to the 4X4 system. It was not meant to work as a replacement for the rear differential.

The 4X4 system is to pull you out...and it fully expects the rear wheels to be doing there part to push you out. Best thing I can suggest is to check things out piece by piece. Does the noise exist when in 2wheel drive? If not you may only have problems with your front differential. You may want to take it apart and check out the gears. If they look really worn, go to a junkyard and replace them, refill the differential and you should be ok. It could also be the autohubs, I would have them inspected as well. Good luck!

Well that sort of goes against the advise offered by Kampy in the following thread:

http://www.explorerforum.com/forums/showthread.php?threadid=20540

But there ya go, that'll teach me to trust the internet, eh?
Your advise actually makes some sense, because, I recall that when the vehicle was really acting up, and basically no motive forward was available, in '4WD' with no rear-driveshaft installed, I did notice the front driveshaft spinning. I thought it odd at the time, and then dismissed it, and thought nothing of it. I would expect that this would definitely point to a shot front differential, or autohubs not being engaged correctly.

Thanks for the pointers!

Paul Scrutton

 

[scrutton]

Originally posted by Triton46
OK, now that, that has been established...I think you may have done some real damage to the 4X4 system. It was not meant to work as a replacement for the rear differential.

The 4X4 system is to pull you out...and it fully expects the rear wheels to be doing there part to push you out. Best thing I can suggest is to check things out piece by piece. Does the noise exist when in 2wheel drive? If not you may only have problems with your front differential. You may want to take it apart and check out the gears. If they look really worn, go to a junkyard and replace them, refill the differential and you should be ok. It could also be the autohubs, I would have them inspected as well. Good luck!

Thinking about this a bit more, the slight slippage that I mentioned earlier does occur in 2WD mode. That rules out the front diff and locking hubs as not being the cause of the slippage. While I may have toasted one or the other, which may have caused my problems with staying in 4WD, that can't be the problem relating to the slight slippage I get. Damn, that's a shame.

Paul Scrutton