Interesting 4x4 Issue

[venmuss]

Coming home from work this morning, I engaged 4x4 Hi as I was rolling up to a stop sign. There was a heavy clunk and the 4x4 light did not come on. The 4x4 had been working flawlessly so far this year, and for the previous 15 minute drive. I hit the button a few more times, to no effect. When I took off I noticed I was in 4x4 and thought I had lost a gear in the tranny when I realized - it's stuck in 4 Lo. I then put it in neutral and pressed both 4x4 buttons several times with nothing doing. No noises, no lights. Even though I was in drive at the time, and no lights ever came on the dash, it shifted into 4 Lo, and now I'm stuck there. I'm turning 3000 RPM at 25 mph in Drive with the hubs unlocked. LOL. Now what??

1994 4.0L Automatic, On-The-Fly 4x4

 

[RonD]

Welcome to TRS

Could just be a fuse blew, the "on the fly" 4x4 is control by an electric motor on the transfer case.

Go to this page:
http://www.therangerstation.com/tech_library/transfercasetroubleshooting.htm

Then click on "Diagnosing 1994 & Older Electric Shift Transfer Cases"
It will have a step by step to get you going again.

On my '94 the electric motor would freeze up now and then, until I replaced it, a tap of a hammer would free it up temporarily , that's a 'tap' not swing, lol.

 

[venmuss]

THANK YOU for the reply Ron. I took the shift motor off and gave it a few whacks while pressing the button but it wouldn't budge - not even with an impact. So I ordered a new one. There were two wires from the motor going up to the TC. One looked like it went right in, one had what looked like a boot. I can take a picture if needed - the reason I'm asking about it is it doesn't look like these wires are part of the new unit based on the pictures I've seen. Do you know the function of these wires?

Thanks again!

 

[venmuss]

Just wanted to update this in case someone else comes across it. A new shift motor fixed my problem. The new motor did not have the wires going up to the TC, so for now I just cut them and insulated them. The plug for the new motor was missing the prongs for these wires. Perhaps the technology has advanced and they are not needed anymore. Everything is functioning perfectly so far. If that changes I will update this thread. Thanks again for your help, Ron.

 

[RonD]

Thanks for the update

And good work

 

[feellnfroggy]

Those two wires should have been a speed sensor? so it doesnt "shift on the fly" while doing 70. Had you read the writeup on cleaning the shift motor, its a 20 minute job and alot safer than smacking with hammer or impact. Either way you got your problem solved. but for future reference, cleanin the shift motor is good maintenance.

 

[adsm08]

You are supposed to transfer those wires to the new plug. The connectors can be de-pinned with a seam-ripper or small screw driver.

One I think is a speed sensor, the other is a clutch coil to get the front drive components spun up before engagement to soften the engagement and improve mesh quality (think unsynchronized trans).