`93 XLT with 'dead' 4WD

[bawalker]

Hello all,

I'm new here and this is my first post. Currently I own a forrest green 1993 4D XLT Explorer that was purchased from family friends two summers ago with 119k miles on it. For the most part it was a vehicle for me to meet my needs of getting me from point A to point B in this region for my computer consulting business. I had planned on saving and getting a Subaru Outback to use for the majority of my distance driving while keeping this Explorer to run till it dies. However I'm had *many* problems appear within the last few months, and they continue to appear. I would like to fix the problems as they arise on my own as I do have a solid technical mind (I'm a computer engineer) so I'm familiar with how many things work, or am able to learn really fast. Mainly because if there is something that I can fix here at home and solve the problem, I'd gladly do that.

Anyway the largest of the problems I have right now is that the 4WD no longer works. This is an electronic/automatic 4WD hub so all I have to do is press the 4WD button or 4WD Low button on the dash panel to engage the 4WD. Early this summer when I tried using 4WD for a rocky driveway, I had to press the button several times before the 4WD engaged. Over the next few months it went from pressing several times to having to press it really hard and finally to hitting the top of the dash for it to engage. Something tells me this is purely an electronical switch problem that could be solved by taking out the 4WD 'switch' in the dash to fix or replace.

Am I correct in my theory? If so how do I go about diagnosing and fixing this?

I greatly appreciate the help!

Brad

 

[DeRocha]

Hi Brad and welcome to the site.. Your question is at the top of the list of most often asked questions... In most cases the problem lies within the electronic shift motor attached to the T-Case.. Over time a plastic stop bumper within the unit deforms and falls apart. This allows the geared position sensor to move beyond its operation range causing the no - shift condition you're experiencing.. Check out the following threads: Shift motor problems and Shift Motor Rebuild

 

[bawalker]

Thank you very much for those links and sublinks. They were very helpful in me finding out about what might be the problem. Being that I'm a complete and utter newb to working on cars, I assume that this shift motor & T case are located near the front end of the vehicle somewhere directly beneath the drivers/passenger seats?

Are there any step by step instructions on what to do first, then second, and so forth when it comes to removing it? The one page had excellent instructions what to do when the shift motor is already disassembled. But I'd like to read up on getting it disassembled and removed first.

 

[DeRocha]

I would start with the simple things first (the stop bumper)... Mark the cover and case with a sharpie so you can install the cover in its original position. Then remove the torx security screws from the cover and pop of the cover... The geared sensor will then slide right out (you may need to wiggle it side to side while pulling out). check the case for any debris and clean/blow out. If the plastic stop is gone replace it with a piece of 5/16" fuel line. All this info can be found in the various threads regarding the shift motor...

 

[Tony H]

The Shift motor is in the back of the trnsfer case. Slide under the car, look up at the Driveshaft and follow it toward the front of the car. The shaft bolts to the Transfer Case. The Motor is right there . Look for wires and connectors going to it.

 

[bawalker]

Thanks for the tips. I was able to find the Transfer Case as well as the wires running to/from the geared sensor. My question is, do I need to take out the entire transfer case and disconnect the drivetrains?? Or can I simply unbolt the gear sensor unit to bring it inside to clean and check the stop bumper?

I would start with the simple things first (the stop bumper)... Mark the cover and case with a sharpie so you can install the cover in its original position. Then remove the torx security screws from the cover and pop of the cover... The geared sensor will then slide right out (you may need to wiggle it side to side while pulling out). check the case for any debris and clean/blow out. If the plastic stop is gone replace it with a piece of 5/16" fuel line. All this info can be found in the various threads regarding the shift motor...

 

[DeRocha]

No need to do anything other than marking the cover with a shapie and removing the geared position sensor...

 

[iceplorer]

4wd not working

Hi.
Well, you can get a book from Haynes for your Explorer, it is very good and everything is taken step by step there. About this problem I think if you hit the dashboard and that helps getting the car into 4WD, the problem is not the T- case itself, must be some connection problem in the 4WD button.

 

[savagefan]

x2

 

[Bwana Bob]

Yes, you can take out the shift motor without removing the transfer case. The switchcontacts for the motor position sensor may just need cleaning.

Before you do that, just unplug the electrical connector that goes to the shift motor. Spray the contacts at the cable and the motor with a good quality contact cleaner and work the connector on and off a few times. I found that high resistance/oxidized contacts can also stop the shift motor from working. With mine, I would press the 4X4 switch, hear some relays clicking in the control unit (inside the jack and lug wrench compartment), but no 4X4 lamps. After cleaning the connector, it worked again.

Also, on the control unit, there is a test button and an LED for checking the 4WD system.


Bob