Auto 4x4 will not engage

[Wucko]

I have a 1992 Explorer Sport 4x4. When I push the 4x4 button I get the clicking noise but the auto hubs do not engage. What do I need to do and/or check?

 

[slim]

Tim, your problem one of three things. One could be they get dirt and grim build up inside and they freeze up. Two, it could be a bad bearing inside. Finally, they have some ware inside. Check out this thread, we have been successful at making auto-hubs work again.

http://www.explorerforum.com/forums/showthread.php?threadid=21469

slim

 

[Longs]

If your 4x4 indicator light doesn't stay on, it's probably the shift motor on the transfer case. Search for threads on that subject, plenty of information here on how to fix it at no cost.

 

[BExplorer]

4x4...

I have the shift motor go bad a week ago, now it is the positionning sensor that died one me. I'm thinking..... If you want some kind of answer go to DR.BOB page, Dead Link Removed under transfercase, good luck.

 

[Wucko]

Still not fixed...

I looked at the Dr BOB page and I tried the standard fix...I pulled the transfer motor, cleaned the armature, cleaned the limit switches. Nothing. I remove the motor once again and tested the motor when it was not mounted on the transfer case. The motor indexes with no problem from 2WD to 4x4 and 4x4 to 2WD...no luck going to 4WD low. But once again when the motor is mounted on the transfer case it doesn't budge. It doesn't even sound like it is trying to move...it may be difficult to hear.

Does anyone have any more ideas?

 

[BigSmooth]

Re: 4x4...

Originally posted by BExplorer
I have the shift motor go bad a week ago, now it is the positionning sensor that died one me. I'm thinking..... If you want some kind of answer go to DR.BOB page, Dead Link Removed under transfercase, good luck.

Make sure you have your explorer in NEUTRAL before switching to 4low

 

[Wucko]

Positioning Sensor??

What does the positioning sensor do? Where is it? Does it sense the actual position within the transfer case or the position of the motor? With the motor lying on the ground and electrically connected, the motor indexed and the lights on the dash indicated that the motor had changed position.

 

[Longs]

Wucko - check "Alfredo C"s comments and picture on the Dr. Bob page under

Dead Link Removed

The white wheel with the printed circuit he makes reference to (below the connector in the photo) is the sensor, along with the other two parts immediately left of it. He says the part was separated, which was a problem, and he had to repair it somehow... I don't remember that being a problem in mine. Also, do you have the rubber stop around the peg on the gear (the peg is at about 5 O'Clock on the gear in his picture).

If you take the sensor apart, be sure to scribe everything first - it's important to line everything back up upon reassembly. I believe the sensor detects the position of the transfer case cam. I cleaned the "printed circuit" and the five little contacts with contact cleaner, and made sure that they weren't bent down so that they'd have good contact with the printed circuit. Apparently various combinations of continuity from those five contacts against the printed circuit let the sensor know where the motor/transfer case cam is pointing.

From the second picture, the motor should rotate the lever 90 degrees going from 2H to 4H, and another 180 degrees to 4L. Does your motor move this much when you have it's unbolted from the Tcase? How about if you hold it up like it's bolted to the case? does it still move?

 

[Triton46]

Can someone post more pictures? This helps alot. I'm wondering which one is the armature? Where are the springs that we are told to be careful of them popping out?


And where in the second photo is the brown wire that we have to cut (or dont in some posts)?

 

[Longs]

Triton - the armature is the part of the motor (copper showing) where the carbon brushes ride - the circular band immediately below the copper showing in the picture. The two little springs are immediately above the gear and to the right of the windings of the motor.

One of the two carbon brushes (black) with its copper lead is the highest component visible in the picture. The springs go in the two slots that are lined up at about 1 O'Clock and 7 O'Clock in the picture in the white base the carbon bruch is attached to.

 

[Wucko]

Longs...I have had the sensor apart already, I just didn't know it. I had to replace the plastic that was on the stop because it was about to break off. I used a piece of rubber hose.

I did not scribe the sensor when I took it apart but I was able to get it back to its original position. Part of the gasket for the sensor cover was left on the sensor body so I could line everything back to original position. The printed curcuit did not look bad I cleaned it up and put it back together.

When I activated to positioning motor with it on the ground it did turn 90 degrees when going from 2WD to 4H...I did not put the transmission in neutral so I think that is why I could not get the motor to shift to 4L. I did loosely bolt the postioning motor to the transfer case and it turned and lit the 4WD light on the dash. It appears that as the motor turned it forced itself off of the transfer case cam and did not actually position the cam. When I tightened the positioning motor down...I got only the series of clicks? Could the transfer case cam be froze up? Or do you think the sensor is out of position? Or something else?

 

[Longs]

Wucko - with everything you did, it sounds like your motor is working properly. I haven't seen anything on the board about the transfer case "freezing up" or mechanically being unable to move from 2H to 4L or 4W, but it does sound like that's what's happening to yours.

If you loosely bolted the motor up to the housing and the motor worked without turning the cam, I would think the motor is OK.

I don't know if it's possible, or how easy it would be to physically move the cam with the motor off, or if you might be able to turn the front drive shaft a little bit - maybe something is just bound up.

 

[mrsteve]

Okay I went to this site: Dead Link Removed
and I did the "test" it talked about. Basically what I did was got in behind the rear access panel next to the jack and rear windshield washer container. I removed the 2 wire harnesses and placed turned on the ignition switch. I pressed the white square button and the red light stayed on. It did not flash. If it flashes that means I have a problem with my actuator motor, but it did not flash. If it stays bright there is a problem with the processor board. What does this mean now? When I press the 4x4 button I hear the board "clicking" but no light turns on and I do not go into 4 wheel drive. Any suggestions?

Steve

 

[Wucko]

Steve--

I did the same test but the light flashed. So I started on the positioning motor... I have no suggestions at this point for your situation.

 

[mrsteve]

Could it be a fuse some where??

 

[Wucko]

mrsteve..

I would not think so...but I do not have a electrical schematic of the 4WD system, so I can not be sure. If you ever run across such a schematic let me know where you got it.

 

[mrsteve]

I checked the fuse panel under the hood and it was fine so that's another thing to cross of the list. I think I may take it to our mechanic and get an estimate and have him tell me what's wrong. If it's nothing to serious I'll just do it myself.

Steve

 

[Wucko]

I would be interested in what you find out from the mechanic.

 

[mrsteve]

Well the mechanic told me it would be $600 for a new motor installed. I told him forget it so now I am gonna try and clean it. Anybody have any suggestions or wants to walk me through the process?

Steve

 

[csturdivant]

TransferCase

I can't get into the Br. Bob site and could sure use the electronic shifter troubleshooting. Would someone please send me a copy. I have Saturday set aside for troubleshooting the system.