I have a 1991 Explorer XL 4x4, with the push-button transfer case selection, that has an odd issue that it will not engage the four wheel drive when I push the 4x4 button. The 4x4 light will come on, but it is definately NOT in four wheel drive. If I then push the 4 Low button, it will engage, AND go into four wheel drive, but if I don't use 4 Low first and then switch back out, it won't engage the front axle.

I can hear the relays shifting when I push the 4x4 button (they sound like they're in the rear cargo area), and can definately tell when 4 Low is engaging. Another thing I've noticed, if I push the 4x4 button, but shut the vehicle off before I get the front axle engaged, when I restart it, the 4x4 indicator light is off again.

Does anyone have any idea what might cause this? It's not too much of a "problem", per-say, but I like having a vehicle where everything works like it should (like my '85 F-150, but it has a manual shift lever, instead of the push-button). I'm thinking it's probably the electric solenoid that controls the transfer case selector, but I've never had a 4x4 that didn't use the shift lever before.

 

I have limited experience with my '92, but I see two possible issues here. First, it sounds like you still have auto hubs. If too much grease is packed in there, or the grease has hardened, the hubs may not work properly. They only need a thin layer over the surfaces inside the hubs. Second, there are several threads on the forum, (and a sticky), on how to rebuild the shift motor on the transfer case. When I did mine, I noticed a rotating plate with electrical contacts that are prone to not making the connections needed due to corrosion.
Try this link....
http://www.marx7.org/~dsmith/t-fer_case_motor_fix.htm
Scroll down a page or two to see a list of 4 different possible failures of the shift motor. There are other better links with pics, but I cant get those to work here.

You may have other issues with the control circuitry, (relays, controllers, the switch on the dash, etc) but the shift motor and auto hubs are common weak links.

 

Thanks, woody. I do have automatic hubs on the Exploder. I'll have to check that first... No telling when they were last looked at.

My F-150 also has auto hubs, but I've never once had a problem with them. Though, from what I've read, a LOT of other people have. That'll be where I start looking first. Later on, when I'm bored and have more time, I'll check into the rest of it.

 

oops I was editing my post when you replied....

 

Heh. Sorry 'bout that. Since this isn't my primary vehicle, I'm not too worried about it. This will probably end up being a "project car" of sorts, later on.

I don't suppose there's any way to convert this to a shift-lever style without replacing the entire transfer case?

Also, what other vehicles have engines that interchange with this vehicle? (4.0L currently)

 

The shift motor on the T/C only operates when 4x4lo is selected. 4x4hi is engaged by an elecromechanical clutch in the T/C (no shift motor). When the front axle is engaged it must rotate through the front pumpkin to engage the front shafts/auto hubs.

 

I've been wrong before, but I don't think so on this one...

The auto hubs being stuck would have ABSOLUTELY NO EFFECT on whether the t-case and indicator lights are properly functioning. If the auto hubs are due for service, then by all means, go ahead and service them, but don't expect this to solve your t-case issues.

If the t-case were functioning properly and the auto hubs were bound up, or the u-joints were toast, your t-case would still engage and the indicators would work normally, but your front wheels may not turn.

Mike

 

Mike, you're correct about the auto hubs having nothing to do with the indicator lights and t-case function. I was only hoping to point out that they're a weak link in the overall 4X4 function. I should've been more clear. However, I still think the shift motor can be a culprit here. I have a picture (This morning, I've been unable to post it here or in my gallery for some reason) that shows the t-case side of where the shift motor mounts. The shaft that gets rotated by the shift motor has 3 positions labeled in the casting of the t-case...2H, 4H, and 4L. It sure looks like the motor operates the 4-high function to me.

 

I agree woody, the shift motor is high on the list of suspects, very common problem on these older trucks.

I'm amazed no one has chimed in to say to switch to Warn manual hubs yet...

Mike