Explorer 4X4 problems

[meatz]

I'm trying to help my brother from across the country via phone. He is working on a 98 Explorer Sport 4x4. This thing has many issues. The questions i'm going to ask all relate to the 4WD though. Ok. Where to start. Let's see... The four wheel drive is shifted electronically. When in 2WD it has a traction sensing feature that will throw it into 4-high when it senses slip. One of the issues is that it will go into 4-high and stick there. One can be driving in a straight line on the road and it will just jump into 4wd. I am thinking that might be a bad ABS sensor. What do you think? Then, when there (in 4wd), there is a constant clicking/popping noise which can be felt throughout the truck. It almost sounds like what slipping hubs sound like. I told my brother that and he told me it isn't equipped with hubs. Is that right? I then suggested to him that he check the transfer case for malfunction. He has yet to do so. He is stating that he jacked up the whole truck and ran it in 4wd and that the front is in low4 while the back is in 4high. Is that even feasible? Any help you guys could provide would be awesome.

[83yellowyota]

check out www.explorerforum.com you can probally find your answer there

[chris1044]

1) Clicking and poping sounds to me like the description of a bad CV shaft (found in the front of it)

2) the thing may be staying in 4wd for a number of problems, but a bad ABS sensor *could* do it - however, I'd think that would be unlikely because you didn't mention an ABS code nor if the ABS was working when he hit the brakes (even with a slight variation in one sensors from the others you should still feel it)

Maybe a bad shift motor??? How does he get it out of 4wd? Shut the car off then its fine?

When jacked up off the ground the front cannot be in 4 low while the rear is in 4 hi. As far as I know the explorers were never equiped with a T case that has a viscous clutch or torque transfering mechanism, which would be the only way for the thing to be in "4 lo" and "4 hi" at the same time

[meatz]

Thank you Chris. You're right, i didn't mention any ABS codes, which i should have. The ABS light comes on intermittently and i guess has been for some time. It will lock up all tires on a hard brake.
Not to sound like a retard, but do you know of a test he can run on the shift motor? Thanks again for your input.

[chris1044]

You should check over on therangerstation.com for the test on the shift motor, in their tech articles, I know they've got a few and some on how to rebuild them

[meatz]

Thanks Chris. i will do that.