1998 Explorer 4x4 transfer case loud banging

[blongo]

All of a sudden my 1998 Explorer 4x4 has started making a repeated loud bang noise under moderate load such as accelerating on the freeway.

I put it on a hoist today, had an assistant sit in the car in drive, foot on the brake, and give it some gas. The noise occurs when the front drive shaft starts to "torque up". It starts to rotate a little and then "bang" and it snaps back. It continues to do this a few times per second once the load gets high enough. The source of the noise seems to be related to a wind-up and release of the CV joint on the front driveshaft.

I took the front driveshaft off and the driveshaft CV joint feels OK to me. There was some thick red lubricant coming out of the small hole in the rounded end of the CV joint. Is that normal?

From what I understand about the "control trac" 4x4 system, even in "auto" the transfer case is engaged somewhat.

I have some questions about this problem and the system in general...

Could the transfer case be "slipping"?
Could the problem be the CV joint on the driveshaft somehow?
Could there be some other fault such as in the computer not properly engaging/disengaging the transfer case clutches?
Is it OK to drive the car with the front driveshaft removed until the cause can be identified?

Thanks in advance for any help!
-Bob

 

[gavin]

those POS CV shafts are known to be problematic. If the noise isn't there when the shaft is not installed, then it's the problem.
As for wether or not it's ok to drive without the shaft.. I would think so, but I'm not positive. I don't know anything really about the Control Trac.

And yes, some "thick red lubricant" coming out of the small hole at the end of the cv-joint would be some-what normal... that's just grease for the CV. You could try packing some more grease in there and see if the noise persists

 

[Mbrooks420]

In Auto4wd the t case will send a signal to the TOD clutch when it senses that there is slippage in the rear. I think it always sends a small amount of power to the front axle, but it mutiplies it as it thinks there is more slippage. I would guess that your TOD clutch in the transfer case is bad. This is a fairly common problem.

 

[blongo]

Transfer case chain slipping?

Could the problem be the chain in the transfer case slipping and "jumping" on the gears? I've read that stretch with the chain is a problem.

 

[Mbrooks420]

I doubt it. Usually a chain streched long enough to skip would make a growling against the side of the case. With it always turning, it likely would rub a hole in the t case in short order.

 

[Parydberg]

Transfer Case?

I just read your post and have exact same issue, did you ever find out cause?