Please Help, I've tried the search function.

[XLT Lou]

I have a 98XLT 4 door 4.0 ohv with 155k on it, The problem i am having is during hard acceleration or going up a hill the truck jerks like the auto 4whl is turning on and off. Now when it is doing this and I switch it to 4whl High it stops . This is happening on smooth dry pavement. Can the transfer case slip in 4whl auto and not in 4whl high or is there a sensor or relay that controls the auto function??? Thanks in advance Lou

 

[Gator Jeff]

A couple things: First, although your attempt at self diagnosis is admirable, using 4WD hi or low on dry pavement will cause bad things. You don't want to have an even bigger repair.

Second is a question, or a few actually.
Are the 4WD HI and Low lights flashing? That would likely happen if the 4WD components are at fault.
Is your check engine light on? If so, go to an auto parts store that reads trouble codes. Get the code and do a search of that. Also, add it to this thread. We've seen it all.
Finally, how long have you had your Ex? Have you had any major transmission repairs? The transmission in your (our) Explorers that have the OHV are notoriously weak. I know that's not what you want to hear, but it's the truth.

Get us answers to those questions and we'll be able to help a lot more. Good luck!

 

[XLT Lou]

A couple things: First, although your attempt at self diagnosis is admirable, using 4WD hi or low on dry pavement will cause bad things. You don't want to have an even bigger repair.

Second is a question, or a few actually.
Are the 4WD HI and Low lights flashing? That would likely happen if the 4WD components are at fault.
Is your check engine light on? If so, go to an auto parts store that reads trouble codes. Get the code and do a search of that. Also, add it to this thread. We've seen it all.
Finally, how long have you had your Ex? Have you had any major transmission repairs? The transmission in your (our) Explorers that have the OHV are notoriously weak. I know that's not what you want to hear, but it's the truth.

Get us answers to those questions and we'll be able to help a lot more. Good luck!

Let's see if I can answer
1)My test putting it in 4whl hi was going in a straight line and only for about 10 seconds, I did it twice, 1/2 hour apart with the same results.
2)No 4 whl light is flashing and they come on when switched to high and low
3) No CEL
4) Have had it for about 5 years, No tranny problems at all other then a 5 second delay going into reverse after sitting over night that started a few months ago. Changed the fluid and filter last weekend and that took care of the delay.
Thank you for your quick response

 

[gijoecam]

Happy to help, Lou...

Rest assured that locking it into 4high for a short period of time (short being the operative word) for troubleshooting and diagnostic purposes isn't going to do any significant long-term damage. But as GatorJeff mentioned, operating it like that on dry pavement (or any high-traction surface for that matter) is not good for it.

It's actually quite normal. The 97-01 Explorers' control-trac automatic four wheel drive operates under a set of pre-programmed parameters. It takes into consideration the operating conditions (speed, throttle position, engine load, transmission gear, etc) and adds in the wheel (or in some years driveshaft) speed sensors, plugs all that into some formula, and determines an output signal for the transfer case to lock 'automatically.' In reality, it doesn't lock, it varies the duty cycle to the clutch froma minimal value (unlocked) to a maximum (locked) and under the conditions you described, it tends to feel as though it's cycling in and out. This is the normal operation of the transfer case in auto mode. Mine's done it since day-1.

Now, as a remedy, for control freaks like myself, check out the 'Comprehensive Brown Wire Mod' thread located in the list of sticky threads in this forum. It'll eliminate the clunking, and wrestle control of the transfer case away from the egg-heads in Dearborn and put it back in the driver's hands.

(I apologize for the pictures not being back up yet... Been busy around here...)

-Joe