4wd Problem with 98 ford explorer

[Efebert]

Need a little help tracking down a problem that I am having with the 4wd on a recently purchased 97 explorer. I took it to a local mechanic but he could not track down the problem.

Here is what the symptoms are, when turning in 4wd(low and high) it makes a screeching noise from the front end. This sound doesn't occur when the vehicle is in AWD or going straight in 4wd. The mechanic change the transfer case fluid and noted that he didn't see any metal on the magnetic tip of the plug. Also, he said it will not make the sound when turning the wheels when the vehicle is on the lift. No wronging lights on or blinking.

Keep racking my brain, on why it would not make the noise with the engine weight off the front end. The vehicle is in very good shape besides this issue. Seems like the mechanic has given up because he has requested for me to pick the car up. Any thoughts on where to start on tracking down the issue?

 

[masospaghetti]

If you are on dry pavement, the 4WD system will make a lot of noise and bind while turning, this is normal. All four wheels are locked together and forced to turn at the same rate. Obviously, dry pavement has a lot of friction and doesn't allow the inner wheel (which wants to travel slower than the outer wheel) to slow down easily, thus the noise and unpleasantness.

In "AWD" (you mean auto 4WD, right?) the front and rear axles are not locked together, and power is only applied to the front axle if slipping occurs via an electronic clutch.

So it appears your 4WD system is working properly!

 

[Efebert]

Wow, I didn't know that the 4wd on the 97 explorers made so much noise due to the different turning rates of each tire. Other vehicle that I have rode in don't make near as much noise in 4wd but I will take your word for it and test it out on the sand! Great news!! Now on to replacing the driver side window regulator.....FUN!!! Thanks again for the helpful info, Erik

 

[masospaghetti]

Some 4WD systems are full-time and don't make noise on dry pavement. These have some type of coupling that allows the wheels to travel at different speeds. The Explorer's doesn't have this.

The AWD system that the V8 models come with is a full-time system though.

 

[Efebert]

Okay, picked the 97 explorer up from the shop this morning and talk to the mechanic. He was aware of how the front end operates on dry pavement and stated that this is not my issue. He said it feels like the front end is binding up when making a turn in 4wd(tested on grave) and makes a popping sound when it lets go. He feels like it is something it the transfer case but didn't what to start taking it apart blindly. Asked about the hubs and suspension but he didn't feel the issue was with that part of the front end.

My question now what does the gears in the transfer case look like? Is it a worm gear or operated with a chain. I have done all my front end work on my 98 explorer sport(upper/lower ball joint, shock, tie rods ect) but when it comes to 4wd I am a novice. Any advice out there??? -Thanks, Erik

 

[masospaghetti]

It's a chain driven system. Is the driveshaft binding? I think your front shaft has a CV joint which is a fairly common fix. Rebuild kits for just the CV joint are readily available.

 

[Efebert]

Might be the driveshaft, just got it home yesterday and noticed that the swaybar links on both sides are loose. Very loose, they has about a 1.5 inch play up and down. Planning on replacing them tonight. During my brief inspection of the front end I didn't see any cracked boots on the cv joints, ball joints, or tie rods. This weekend I will get it onto jack stands and give it a good shake down. How would I tell if the driveshaft is binding? I don't have a lift to run it in 4wd and the mechanic said it didn't make any noise when on the lift. Thanks for all the info thus far!

 

[RomeovilleIL]

Let's review. You are not getting any noise or issues in the auto 4wd mode. 4HI and 4LO no noise in straight line driving and no noise when on a lift turning, but get binding on pavement and gravel. Sounds like the system is working normally. Gravel and pavement are generally both fairly good traction road surfaces which your tires will grip. Try the 4WD on loose surfaces like wet grass, mud, sand, etc.

 

[Efebert]

Replacement of both sway bar links fixed the problem. Definitely didn't think that the links would be the issue but it worked. Thanks for all the help!! -Erik