Slipping into 4x4

[Knmcc]

Not sure where whether to post this in Stock or mod forum, so please move if necessary. (my x has a few mods not sure if they apply to this or not)

Just bought my 2nd 4x4 x. Had to remove the front drive shaft after 3 days because it kept slipping into 4wd while driving down the road. Transfer case seems OK although it was clunking a bit during the mishap. I know that the front and rear diffs need new seals. Cv axles may need some attention, but I won't know until it's taken apart.

My question is, what the heck would make it slip in and out of 4x4 while driving down the road? electrical? Transfer case chain? Transferccase motor? Has anyone had this issue? The guy I bought it from has already replaced the rear end with a "performance" rear end, but he couldn't give specs because he didn't remember what make it was and didn't want to tell me who did it. I'm a little frustrated but I want to get it sorted out. Thanks in advance

 

[Knmcc]

Just wanted to add, none of the 4x4 indicator lights were coming on when it was engaging. Only if I manually pushed the button to engage would they come on.

 

[wbrudi28]

when the truck is in 4x4 (auto), no indicator lights light up on the dash.

I would install the front driveshaft again, then put it into 4x4 high and drive down the road. Does it still make those clunking noises? if it doesn't then it could be the following:

1. how's the road conditions? are they sandy or uneven?
2. how are the tire conditions? are they evenly worn on all 4 tires? better yet, make sure they're all the same size, brand and tread pattern. this could be causing the 4x4 to engage (and destroying your t-case in the process)

3. If neither 1 or 2 are a problem, then it may be your ABS sensor on one of the front hubs. a faulty ABS sensor could tell the computer that a wheel is slipping and quickly engage full-time 4x4.

i don't believe its your t-case, because of the intermittent engaging of the front drive shaft.

i'd check that stuff, then come back and give us the verdict. good luck!


EDIT- either way, I would install the front drive shaft, and do the brown wire mod. this way, you can shut the power to the front wheels off, but flip it back on in the winter if you need to engage 4x4 High

 

[BigRondo]

I have deleted your other thread since it was a duplicate and this thread has received replies.

Please only post 1 thread per subject. :biggthump

 

[Knmcc]

I have deleted your other thread since it was a duplicate and this thread has received replies.

Please only post 1 thread per subject. :biggthump

Sorry! I thought I only posted it once?

 

[Knmcc]

Before I took the front drive shaft out, tried to put it in 4x4 and it went clunk clunk clunk.. Honestly it felt like the front end was going to fall out, and that was what it was doing when it'd slip into 4x4 while driving. So that was when I tried manually and it still did it.

Road conditions are/were smooth pavement. I'm in FL so it's hot and winters are mild. I mainly want to have the 4x4 for beach use. Tires are all the same, fairly new with hardly any wear (Hankook Ventus as 245/70/17).

Abs makes sense. SES light came on while I was test driving the day I bought it so I plugged in my code reader and it threw B2900 and U1900, which are both abs codes. Didn't think of that messing with 4x4, though! Gonna have to do some investigation now.

when the truck is in 4x4 (auto), no indicator lights light up on the dash.

I would install the front driveshaft again, then put it into 4x4 high and drive down the road. Does it still make those clunking noises? if it doesn't then it could be the following:

1. how's the road conditions? are they sandy or uneven?
2. how are the tire conditions? are they evenly worn on all 4 tires? better yet, make sure they're all the same size, brand and tread pattern. this could be causing the 4x4 to engage (and destroying your t-case in the process)

3. If neither 1 or 2 are a problem, then it may be your ABS sensor on one of the front hubs. a faulty ABS sensor could tell the computer that a wheel is slipping and quickly engage full-time 4x4.

i don't believe its your t-case, because of the intermittent engaging of the front drive shaft.

i'd check that stuff, then come back and give us the verdict. good luck!


EDIT- either way, I would install the front drive shaft, and do the brown wire mod. this way, you can shut the power to the front wheels off, but flip it back on in the winter if you need to engage 4x4 High

 

[Knmcc]

Edited to delete double post.

 

[BigRondo]

Sorry! I thought I only posted it once?

No worries. Good luck getting it sorted.

 

[Knmcc]

Ok. I researched a little about abs module, rear speed sensor, 4x4, and the codes. Somebody please tell me if this makes sense because I'm trying to piece together the problem.

If previous owner had the rear differential rebuilt with non oem or some kind of "performance" rear end (that's what he called it, he acted like he couldn't care less about whether the parts were right for the truck or not), could it be possible that the rear speed sensors were damaged or overlooked? If I understand correctly, there should be one right above the rear differential. (I've got to take the rear diff cover off and change the fluid and seal anyway so I'll check when I get to that)

Anyway, if that sensor is the problem, could it be misinterpreting the speeds of the rear wheels and hence trying to kick into 4hi while driving?

Somebody?

 

[2Trux]

The other possibility is when the rear was rebuilt the gear ratio was changed and doesn't match the front anymore. This could destroy your transfer case.
ABS codes, speed sensors, and going into 4X4 could be tied together.

 

[wbrudi28]

I honestly couldn't tell you about the speed sensor in the rear.

did he mention the rear being a locker?

 

[Knmcc]

I honestly couldn't tell you about the speed sensor in the rear.

did he mention the rear being a locker?

Nothing about that at all.

 

[Knmcc]

I honestly couldn't tell you about the speed sensor in the rear.

did he mention the rear being a locker?

Nothing about that at all.

 

[Ronin8002]

I don't believe a locker would cause the behavior you are seeing, at least I never experienced it in my 3rd gen with a locker and haven't read any reports of others who had one experiencing it either. The whole performance rear end thing sounds like bunk, or else the guy didn't know enough to be specific.

At any rate, your problem might be related to a TSB:

http://www.allworldauto.com/tsbs/NHTSA_2004_FORD_EXPLORER_technical_service_bulletin_123547.html

...the symptoms sound similar to what was reported in the thread linked below. sounds like the ABS pressure switch was bad and replacing it fixed the issue:

http://www.explorerforum.com/forums//showthread.php?p=2215575

As an additional troubleshooting step, try pulling the 4x4 fuses out of the fuse box under the hood. This will disable the auto 4wd from engaging and may help isolate the issue and make the truck more driveable in the short term. It won't damage anything to drive it like this.

good luck!

 

[wbrudi28]

I don't believe a locker would cause the behavior you are seeing, at least I never experienced it in my 3rd gen with a locker and haven't read any reports of others who had one experiencing it either. The whole performance rear end thing sounds like bunk, or else the guy didn't know enough to be specific.

At any rate, your problem might be related to a TSB:

http://www.allworldauto.com/tsbs/NHTSA_2004_FORD_EXPLORER_technical_service_bulletin_123547.html

...the symptoms sound similar to what was reported in the thread linked below. sounds like the ABS pressure switch was bad and replacing it fixed the issue:

http://www.explorerforum.com/forums//showthread.php?p=2215575

As an additional troubleshooting step, try pulling the 4x4 fuses out of the fuse box under the hood. This will disable the auto 4wd from engaging and may help isolate the issue and make the truck more driveable in the short term. It won't damage anything to drive it like this.

good luck!

+1

id like to see what happened...any update?