Transfer Case disengaging

[Joeker]

I just picked up a '95 XLT with 142k on the clock. I'm a longtime Ford owner, but am new to electronic 4WD and auto locking hubs, etc.

Upon testing the 4WD system it seems Auto 4WD works, however when I engaged 4-Low it seemed to work fine, but when I spun the tires a bit (in loose mud) it "disengaged" and just spun with a slight grinding noise as if the gears were just out of reach. Turning the knob to 4WD or 2WD didn't change anything... it just spun. Then I shut the truck off, & restarted it in 2WD and it worked fine. I had to put it in 4WD high to get out of the mud and it again seemed to work fine.

All of the above was done on wet grass & mud. Any good thoughts or ideas on what's going on? Any other tests I should try?

Thanks for all your help!
Joe

 

[gmanpaint]

Welcome to the forum.

Your 4wd system should be the "Control Trac". You should have a 4405-CA T-case, the front vac disconnect differential. You would have NO auto hubs on this set up.

First off, are you placing your transmission in Neutral, stepping on the brakes, before selecting 4wd Low?

You have to do this again to remove it out of 4wd Low as well. Just going from 2wd to 4auto to 4wL while your in gear wont do anything but activate the control trac in 4auto.

Once we establish your doing this correctly, we can move on to other things.

 

[Joeker]

Thanks for your reply and great info. I guess I have the Control Trac system and no auto hubs then.

I believe I started the X then moved it to 4-low while in park. Will that work or does it need to be in neutral?

I thought the indicator light for 4-low was on. And it worked (at least it moved the vehicle) before it "dropped out".

How would it react if it wasn't put into 4-low correctly?

Thanks again,
Joe

 

[gmanpaint]

You HAVE to be in neutral, and brakes applied, for 4 low to be engaged/disengaged.

The lights might come on, but the shift motor on your T-case will not change the drive range of your T-case, if you don't do these steps correctly.

Reaction will be that of your truck being in 4auto. Abs sensors detect wheel slippage and transfers power to the front end. When the slippage has stopped, and the wheels are all spinning at the same speed, the power is returned to the rear wheels.

Understanding how your truck works and operates will give you peace of mind, and confidence.

I think what you experienced was your control trac operating. You can hear and feel it engaging. When you where spinning your rear wheels, and had it in 4auto(thought 4low), the control trac kicked in, resulting in a thump and thunk in the front end, might have even felt like it was under you, when you released the throttle, it kicked off, making you think it popped out of 4low.

Knowing the proper way to apply 4low now, Try once again to put your truck in 4low.

Find some loose dirt, gravel, sand, to test it in. You will feel the difference right away. Lower gear ratio, front end feels different, and your truck is amazingly quick from a dead stop. Do not try this on dry pavement, unless you do not turn your wheels while doing so. That would/could cause damage to your truck, (expensive!).

Hope this helps. Find a manual for your truck and read up on the control trac system.