4x4 Hi Clunk Problem

[sbrueske]

I have a 93 XLT that has been lifted. It has been snowing lately in Minnesota so today I drove to work in 4x4 Hi on fresh snow covered roads. When in 4 wheel drive I have a clunk that happens ocassionally. It seems to be coming from either the drivers side front wheel or under the drivers seat. It also seems to be consistant with the speed. It clunks about every 200 feet. At 55 mph it clunks every 7 seconds right on the money. As I slow, the frequency of the clunk slows. This does not happen in 2 wheel drive nor have I noticed it in 4x4 low (though I seldom use 4x4 low). It is more pronouced when excellerating and less noticeable when coasting (although still there). Anyone had anything similar to this happen?

 

[pugsy]

I have a similar type clunk, but more so only when I let off the gas and coast at slower speeds (city driving). I think my problem is the U-joints at the wheel - they're pretty rusty. You may have the same issue.

 

[Mud Bug 94]

spin ur front d-shaft by hand with the wheels on the ground and the t-case in 2wd. u-joint.

 

[sbrueske]

U Joints??

Thanks for the input. But if this problem was related to U Joints wouldn't it be much more often, like with each wheel rotation, rather than once every 100 yards? Or wouldn't it be more random that at exactly the same number of rotations? Perhaps I am not visualizing the mechanics correctly.

 

[MrShorty]

Anyone had anything similar to this happen?

My BII did the same kind of thing several years ago. Turned out to be because I had mismatched tires on it. The fronts were a different make/model tire than the rear, and the slight difference in diameter caused the tension in the drivetrain to build up until it released with a clunk/bang. I would check to make sure you don't have one tire low on air pressure (flat tires have a different rolling diameter than properly inflated tires).

 

[pugsy]

This would only be the case when engaged in 4x4. Mine does this (clunks) when the front hubs are locked but the transfer case is in 2hi.

 

[tantonio]

i have a 99 explorer awd drive and the clunk is bad when driving in snow,mud, ice and get worse when in 4hi and 4 lo need to fix it but can't find the problem.

 

[denisb]

This would only be the case when engaged in 4x4. Mine does this (clunks) when the front hubs are locked but the transfer case is in 2hi.

Not 100% sure but wouldn't your transfer case still be turning if your hubs were locked even if you were in 2wd?

And secondly do these use drive chains for transfer case or gear?

 

[pugsy]

yes, you're right the transfer case would be turning still, but not connected to the rear axel. But I was commenting on the part that Mr. Shorty said about having mismatched tires. It would only bind/clunk when 4x4 is engaged. Mine does it in 2hi when the hubs are locked.

 

[DeRocha]

yes, you're right the transfer case would be turning still, but not connected to the rear axel. But I was commenting on the part that Mr. Shorty said about having mismatched tires. It would only bind/clunk when 4x4 is engaged. Mine does it in 2hi when the hubs are locked.

You mean not connected to the Front Axle.

sbrueske, How old are you U-joints? Under normal use they last 100K miles... When worn the lube inside tends to dry out which allows moisture in and the needle bearings rust away... This can lead to th U-joints binding and then being freed, binding and then be freed..

 

[sbrueske]

Thanks DeRocha!

sbrueske, How old are you U-joints? Under normal use they last 100K miles... When worn the lube inside tends to dry out which allows moisture in and the needle bearings rust away... This can lead to th U-joints binding and then being freed, binding and then be freed..

I have only had the vehicle for a few months so I am unsure how old they are. The explorer has 166K on it and I wouldn't be surprized if the U Joints on the front wheels are old. Once I am able to get this into a dryer and warmer place, or on our first 60 degree day I will take a close look at all of the U joints. Thanks for the link showing the job from stu-off road. A picture is worth a thousand words and this gives me more confidence than my manuel did. Looks "doable." Guess I can't imagine what else it could be but U Joints. Not much else involved, is there? Thanks again!