Running at roughly 175K miles and still going.

New problem for me. I have checked the archives and followed those suggestions, but still have the problem. The AWD light flashes 9 times (previous posts indicate a loss of continuity at both sensors). Put new sensor in rear (no change), swapped to front (still no change).
Additional symtoms: After first starting am locked in 4 wheel drive mode, either backing or pulling forward (know by turning radius and wheel hopping on pavement). Clears to 2wd after about a hundred yards or so and then the AWD starts flashing.
Next symptom: Have a tin sounding ratling or draging soud (liken to a heat shield ratle on the exhaust), starts after about a half mile or so. The rattle will increase and decrease in frequency as speed changes. Rattle stops when vehicle stops and will start up again another half mile down the road.
My guess: I have the Dana/Spicer transfer case and I am thinking that the drive chain is stretched and starting to rub the case or other parts.
My imediate question is there an adjustment for slack here, if so how?
I am open to all suggestions espesially if one feals I am off base here.

 

Addressing this in reverse order, there is no slack adjustment. Having recently rebuilt this unit, the chain is incredibly stout and would be almost impossible to generate suffiicient slack to cause the noise you describe. The chain would likely jump off the gears before stretching enough to reach the case and rub.

I would guess the problem lies in either the E4WD control unit located under the driver's seat or the electric clutch within the transfer case - or a combination of both. First step would be to ensure both front tires are inflated properly, are both the same size tires. Afterwards, disconnect the control unit by removing the connector. If you still have lock up of the front wheels the electric clutch pack is bad. If disconnecting the control unit solves the problem, the source is the controller.

Your noise is worrisome as this may be indicative of a failing electric clutch pack within the transfer case.

The transfer case is fairly simple in design and layout. Rebuilding is not terribly difficult if you have a few necessary tools on hand. Getting the TC in and out of a van on jackstands is trickier than it seems due to limited space to maneuver. Renting a low boy transmission jack is highly recommended.

 

Thank you,

I have unplugged the controller and the front wheel lock up has gone away (rear wheel drive only). I would think that this is indicates that the controller works because when conected it still managed to engage and disengage the all wheel drive upon first starting the vehicle. Since I have disconnected the controller the noise has deminished quite a lot and has taken on a more mellow tone, liken to the sound of exposed gears meshing (not grinding).
Is there a series of tests one could do to prove the controller?
The TC rebuild work you discribe sounds more like warm weather activity. Would I be likely to cause much, if any damage, if I put this off for about 8K miles, with the controller disconected? Is there a good source for a good rebuild kit, you would recommend?

 

EBTDM,
Your results tend to point toward a bad clutch pack. Now, whether this was caused by a malfunctioning electronic controller or just inadvertent wear remains to be seen. The change in noise would seem to indicate the clutch pack was being energized during normal road conditions, causing undue wear on the clutch pack. That you still have noise, albeit abated, would point toward plates and/or bearings for the clutch pack.

I would first check to see that the fluid level (AT fluid) is correct and the TC has not run dry. Afterwards, I would leave the controller disconnected until the unit is removed. Whether or not the TC will last until then is anyone's guess. I tend to think by design, it would last another 8000 miles.

Here is an excellent article I ran across for troubleshooting the transfer case: http://www.atraonline.com/html/gears/mar/gmar97p60.htm

As for parts resource, I purchased my parts from www.driveline.com

I did not replace the clutch pack, but did do all the other bearings, seals and chain. After 210,000 miles, there was surprisingly little wear on these items. The chain, which I suspected of being worn, showed only 1-2mm difference compared to the new one. The clutch pack rides on small caged needle bearings and I would be highly suspicious that yours may be damaged. Getting the needle bearings out is difficult without the correct puller due to restricted access.

Hope this helps!

 

driveline.com appears to be a trucking firm in South Texas, not a parts supplier.
It turns out that the front sensor was leaking after the reinstall. Apparently Ford had stripped the case for the retaining screw and had it seated over the miles with some sort of putty that never quite hardened. Any way I am not familar with it, at first I thought it some version of lock tite. When I put it back in, is when I noticed that the case threads were stripped. So the seal around the O-ring was seaping AT. I check the level and although a little lower than I like it, I did not need to add. I am keeping a eye on it till I figure what they used to give the retaining screw the extra bite it needed.

 

Opps! Sorry, I could only copy one website address to the clipboard when making the previous post and I just glanced at the list of other reference sources and stupidly trusted my memory. Here is the correct resource, drivetrain.com. http://www.drivetrain.com/

Their site is pretty comprehensive but a little confusing to maneuver around in. I have used them three times now when rebuilding the rear diff, front diff and the transfer case. All their parts have been very high quality and either original Timken bearings or equal OEM spec.