Front end clunk but only in Auto 4x4

[WhiteTrash]

Hello,
1st- I did search the forum and found alot of threads on front end clunk but could not find one that goes away with 4x4 so im making a new post to help track down the problem.

I have a 2002 with 4.6l. I have a front end clunk that happens only when driving in auto (Truck only has Auto/Hi/Low option). It feels as if the awd is kicking on and off but its constant and worse going up hills and while under acceleration, and by constant I mean every few seconds. Once im at highway speeds I can just barely feel it. But cruising at 20-40 is when its at its worst.
Once I push the button for 4x4 hi the clunk stops, I push Auto and its back instantly.
Bad T-Case? Driveshaft?
Maybe the tire wear is too far off?

An Important note is that the truck had 4 different tires on it at time of purchase and had the same clunk issue. I was able to pickup 4 tires off craigs for $50 bucks but they dont match. The front two are the same make/model and the rear two are the same make/model. All are the same size and the wear is within 1/32nd of each other, ive heard even this small wear difference can cause issues, would it cause the same issue that im having?

I have a 2003 for parts and I plan on swapping over the Tranny/T-case and drivehaft soon in hopes of remedy my problem, unless the problem is the tires or something else.

Thanks!
-WT

 

[rrgone]

You don't have AWD, it's an automatic 4WD system if you have the 3 buttons next to the radio. Matched tires are important and I'm guessing that's your problem. You can try rotating the tires F to R on both sides and see if that makes the clunking better or worse. Either way it will pinpoint the tires as the problem.

If you can't afford a set of new matched tires then you can disable the auto-4WD system temporarily by pulling the power fuses to the transfer case. You could also do the brown wire mod to get true 2WD until you actually need 4WD. Good luck.

 

[WhiteTrash]

Thanks for the clarification for the awd vrs auto 4x4 and you are correct I have the three buttons.
I have already rotated the tires and did not notice any difference for better or worse.
I can afford the tires but I did not want to speed 4-500 on tires just to have the same problem. That's one of the reasons I posted here was to help get some direction on what I should do next.

 

[rrgone]

Sorry, but I cannot definitively say that it's your tires that are the problem. I do know that when my OEM tires were getting pretty worn I started having issues with turning and occasionally when starting off uphill. I would get the 4WD thumping and windup like you describe. I put on a new set of tires and issues disappeared. Hope this helps.

 

[WhiteTrash]

Thanks for the input. Im going to locate and remove the fuses for the auto 4x4 and see what that does and I will research the brown wire mod.

 

[Exproblems]

Thanks for the input. Im going to locate and remove the fuses for the auto 4x4 and see what that does and I will research the brown wire mod.

Pulling fuses #17 and #18 should disable the 4x4 system. Fairly certain they are located in the main fuse box that is mounted in the engine compartment on the driver side wheel well hump. Double check on this with your owners manual.

 

[Limited02]

Pulling fuses #17 and #18 should disable the 4x4 system. Fairly certain they are located in the main fuse box that is mounted in the engine compartment on the driver side wheel well hump. Double check on this with your owners manual.

You are correct.

 

[WhiteTrash]

Thanks guys. Gonna pull them before I leave work and see how it is on the drive home. Do you know if there is anything else linked to these fuses or are they both 100% related to only the 4x4? I know cars can be wired wierd so just wanting to make sure. Thanks!

 

[Exproblems]

. Do you know if there is anything else linked to these fuses or are they both 100% related to only the 4x4? I know cars can be wired wierd so just wanting to make sure. Thanks!

I never had to pull these fuses myself, but if I remember right when I looked these fuses up in my owners manual (which isn't handy at the moment), you just lose 4x4 mode. I don't recall seeing any other devices listed as controlled by these fuses.

 

[WhiteTrash]

Pulled the fuses and the clunk is gone, 4x4low light is on (button only ,not dash) but its just indicating a fault which I already know is the missing fuse. Checked alldata and you are right the 2 fuses are both dedicated to 4x4. Searched alldata for my issue and it list checking tire circumference and and says if one or more tired is off by 1/2in then it is going to cause 4x4 auto to turn on and off. Tonight when I get back from work if its not raining im going to jack the truck up and check out the tires to see if they are all the same circumference, if not then im going pickup a brand new set of tires and see if that remedies the problem..

Thanks for the info/advise everyone, ill report back with my findings later.

 

[WhiteTrash]

I know this is an old topic but I figured it was worth updating with the solution to my problem.
I got 4 brand new tires for the truck last week and the clunk is gone. I also put the fuses back in on my way to get the tires and the clunk was still there so im 100% positive it was the tires being mix-matched and different tread wear that was causing the auto 4x4 to turn on and off constantly.
I have not paid much attention to this problem because I barely drive the explorer. I bought it as a winter car so I can commute the 60 mile round trip to work in bad weather. I have recently been promoted and transferred 6 miles from home and decided to start fixing some problems with the truck before winter and drive it more often.


I went with Yokohama Geolandar H/T-S 235/70/16.. They are smaller then the recommended 245's but I could not pass them up. Buddy who owns a shop bought them for a customer who totaled his suv before they could be put on. And I was already eyeing Yokohama's so it was perfect. Was able to get them @ cost with free mount&balance. I was wanting to go with 245 or 255 for a better look but this deal was to good to pass up and I can deal with my speedo being off by a measly 3mph.



Thanks for the input everyone on possible problems and a easy part time fix by pulling the fuses.

 

[blue_goose]

I know this is an old topic but I figured it was worth updating with the solution to my problem.
I got 4 brand new tires for the truck last week and the clunk is gone. I also put the fuses back in on my way to get the tires and the clunk was still there so im 100% positive it was the tires being mix-matched and different tread wear that was causing the auto 4x4 to turn on and off constantly.
I have not paid much attention to this problem because I barely drive the explorer. I bought it as a winter car so I can commute the 60 mile round trip to work in bad weather. I have recently been promoted and transferred 6 miles from home and decided to start fixing some problems with the truck before winter and drive it more often.


I went with Yokohama Geolandar H/T-S 235/70/16.. They are smaller then the recommended 245's but I could not pass them up. Buddy who owns a shop bought them for a customer who totaled his suv before they could be put on. And I was already eyeing Yokohama's so it was perfect. Was able to get them @ cost with free mount&balance. I was wanting to go with 245 or 255 for a better look but this deal was to good to pass up and I can deal with my speedo being off by a measly 3mph.



Thanks for the input everyone on possible problems and a easy part time fix by pulling the fuses.

Good to hear! a easier way than pulling the fuses is to go under the dash on the passenger side and find the black box that says 4x4cm or something like that, it has 2 sets of wiring harnesses going into it from the bottom. you can just unplug one and its the same as pulling the fuses i believe. Its how i put mine in 2 wheel vs 4 wheel, hasn't broke for over 100k of doing it. and you can do it while driving once you can feel for it. Glad your problem is fixed though.

 

[jstallionman]

IS THERE ANY HARM DONE TO PULL THE WHOLE WIRING CONNECTOR UNDER THE TRUCK FROM THE TRANSFER CASE? BECAUSE THAT WHAT i DID INSTEAD OF THE BROWN WIRE TRICK. DEAL WITH SOME LIGHTS ON THE DASH BUT THAT'S WHAT ELECTRIC TAPE IS FOR.

 

[jstallionman]

Whoa I really didn't mean to yell that question haha sorry

 

[Limited02]

IS THERE ANY HARM DONE TO PULL THE WHOLE WIRING CONNECTOR UNDER THE TRUCK FROM THE TRANSFER CASE? BECAUSE THAT WHAT i DID INSTEAD OF THE BROWN WIRE TRICK. DEAL WITH SOME LIGHTS ON THE DASH BUT THAT'S WHAT ELECTRIC TAPE IS FOR.

No, but now you're 100% 2wd. Do you plan to find and resolve the issue?

Yelling is okay because I'm hard of hearing

 

[jstallionman]

I do plan on fixing the problem. I'm sure its the different tire sizes I have going on. yes.right now its 100% 2wd but that's ok for now. Its easy to plug back in when I have to put the boat in the water at the slippery launches. No problem with me at all to plug and unplug. Even when I do get the correct size I think I'll still do the brown wire toggle switch mod. I like total control if applicable. thank you for the answer to my question so fast on an old discussion. Much ablerged.....

 

[TechGuru]