popping sound in 4wd, 91 2dr

[Raceit]

I've got a 91 Explorer 2dr 4wd. I just bought this, so the problem has been there incase any of you were wondering if I broke it. Mainly turning the wheels left or right (the tires don't even need to be close to the end of the turn) I will get a loud popping sound. Also it has done it ridding the brakes going straight down a small hill (no steaper then a driveway). It will happen in 4wd high or low. It is a hard sound to descibe, but it sounds really bad. Having the wheel turned to the left and with my friend walking in front, he will see the axle stop right before the pop and then jerk as the pop happens, then continue spinning. It doesn't seem to do it every revolution of the tires either. It will disengage and engage 4wd just fine. It has popped out of 4wd low once going up a hill, but I would imagine the popping did that. I just had some front brake work done on it and the guy that worked on it said that the front auto-hubs looked ok as far as the 'teeth' or 'locks' or whatever their called that was visible. He didn't get into the hubs though. I did have a suggestion (which I will do anyways) to get the manual lock-out hubs. But I would like to know for sure what this problem is. Also I am planning to get a lift kit and bigger tires and wheels for it. So I want to try to avoid replacing parts twice if I have to. Sorry that was so long, thanks in advance for any help.

-Steve
raceit600@hotmail.com

 

[PhxExplorer]

Hi and welcome to the site. I am having the same problems that you are and although I don't have a definite solution I do have some tips that I will try myself. The hubs could be going bad. there could be too much grease in the hubs causing it to slip. The front U-joint could be froze up. Or the brushes in the tcase could be dirty and need cleaning. These are just a few of the tips I got from doing a search on "4wd". Try the search it will probably help you more than I can. Good luck!!

 

[miktowle]

Check your radius arm bushings, thatis what was popping on mine. It was also a recall item, which actually ovals out the hole in the radius arm bracket. they replaced at no charge. hope this helps, mike.

 

[FMNavajo]

Raceit,
First, welcome to the site. Second, when your in 4wd, are you on ground that will let the front wheels spin? If not, then you might be close to breaking a hub, u-joint or axle. STOP, do not engage 4wd while on any kind of hard surface that won't let the wheels spin.

If you are on soft ground and your still getting these noises then start off by getting it up on jack stands and checking all bushing, radius arms, axle pivot, sway bar link, and any other bushings you can find and see. If this reveals nothing than have a friend turn the wheel while the truck is stationary and watch the rear bracket of the radius arm and watch for any movement. Do the same with the axle pivot points. One to pay close attention to is the passenger side rear radius arm bracket, this is very close to the cat and exhaust so the bushing don't last that long.

Good luck,
FM

 

[Henry]

Raceit, welcome!

Try FMNavajo's suggestions first, but it sounds the same as a problem I was having a few months ago. There was a popping sound while in 4wd (grass & gravel) whenever turning but rarely, if ever, when travelling in a straight line. It turned out to be one of the auto-hubs was going bad. I got 2 new Warn manual hubs ($208 installed) and the problem is history!

 

[Matt193]

It sounds like I have tohe same problem too- I only got it when I was turning sharply in 4WD. It sounds like my hubs are making all the racket....

 

[Raceit]

First off, thanks for the welcome to the site. I'm sure I'll have plenty more questions in the future. Today I just got my Warn manual hubs installed and then went out and played. It fixed the problem. I watched the guy take off the old hubs. A few parts just fell out of each assembly. Anyways, thanks again fellas for all the help.

 

[JayR]

If you get warn manuals , what happends to your auto 4wd low??? my 4wd is acting funny also so i need to fix this problem. I have pushbuttom 4wd and 4wd low. thanks guys

 

[Raceit]

I have push button as well. It's pretty sweet how it works. Say for example, on a snowy day before you leave for work you just engage the hubs. What that does is engage the front axle and makes them spin, but it is not engaged at the transfer case. If you get stuck or need the 4wheel drive or low. It's just like normal. Push the button to engage it and disengage it (the transfer case that is). It is a must upgrade if your going to do any off-roading. Hope this helps.

-Steve

 

[Raceit]

I almost forgot the best part. You don't have to back up to disengage the system. Just get out and turn the hubs. Did I mention that you don't have to back up?

-Steve

 

[JayR]

Steve, so the old 4wd will still work with the pushbutton?? If so i will be purchasing some manuals sooon. everyone liek them???

 

[Raceit]

They work just fine with the push button. All you have to do is get out and turn the hubs first then hit the 4wd button. Then reverse that to turn them off and disengage them.

-Steve

 

[Henry]

JayR,

The actual push-buttons work exactly as they did before, since all that does is change the "mode" of the transfer case.
With the auto-hubs, when you put the transfer case in either 4High or 4Low the front drive-shaft would be connected and the front drive axles would begin to rotate. As the front drive axles rotated they would cause some plastic cams in the hubs to rotate as well until a metal splined collar engaged the splined axle shafts and power was transfered to the front wheels via the hub. Note, however, that this system would automatically disengage when changing from forward to reverse, or visa-versa. Just imaging what would happen if you where stuck and trying to rock yourself out... moving axles attempting to engage non-moving hubs multiple times in each direction. Can you say "blown hub"?

With the manual hubs you engage the transfer case the same way. Only now, if you don't first engage the manual hubs everything moves, but no power is transfered to the wheels since the hubs aren't locked. On the other hand, if you engage the hubs but not the transfer case you have a lot of extra drag as the front axles and drive shaft are now turning (but I don't think anything bad will happen, just not a good idea to keep the hubs engaged if you're not planning to use 4wd), but not connected through the transfer case. Its probably best to engage the hubs when you think you might need 4wd, then all you have to do is hit the button when you really do need it.

The difference is that you actually have to get out of the truck and turn the dial on each hub. I like the manual hubs despite that... its nice to know they are reliable!

I hope I've helped more than I've hindered!

 

[JayR]

Henry i also have 31's, does yours tow ok ? mines kinda slow with stock gears

 

[Henry]

JayR, I don't (currently) tow with mine. When I bought it (used, about 2 years ago) I didn't even realize it had the towing package. However, I don't even notice a difference in acceleration or performance because of the larger tires, probably due to the 3.73 gears I have. Do you know what gearing you have?

 

[mhskeeper]

What about auto 4wd???

I recently got a 97 EB and really like it. I have the same popping sound that you guys were talking about and want to take care of it. I purchased an extended warranty on it so everything(even stereo components) is covered. I wanted to do the Warn Manual hubs, but was concerned about the auto 4. if i go to ford and have them replaced, it will cost $50, so im not really sure what to do.

So i guess the question im asking is, is it worth it to get the man. hubs if i have the auto????

thanks for the time

 

[TPLYNCH]

mhskeeper,

You don't have the hubs. Those apply only to 91-94 Explorers. 4x4 on 95+ is locked in at the T/F case, not at the wheels. When are you hearing the sounds?? You may have different troubles...... More info may help us diagnose yours.

 

[mhskeeper]

My popping sound

the popping occours when i turn, left or right, after putting it into 4 hi or low. It usually happens after about half a turn or more on the steering wheel. I cant really describe the pop, but it doesnt do it when the auto is selected. Hope this will help you guys determine my problem. thanks

 

[TPLYNCH]

What kind of surface are you driving on when you have it in 4x4. If the ground is hard and doesn't easily allow the front wheels to slip, you will get noises from the front end. In 4x4 Hi or Low you will always have noise when turning, especially on a hard pack surface because of the different turning rates between the front and back tires. When locked in 4x4, the driveline turns at the same speed. The popping is the release of the "windup" caused by differences in the turning speeds. You'll have less noise on slicker surfaces because it is easier for the tires to lose traction and release the windup.