Need help with my four wheel drive.

[skler]

I have a 1999 Mazda B4000 (basically a ford ranger with a Mazda sticker on it) with electronic shifting for the four wheel drive. It is an automatic with a 4.0 L engine. Initially the four wheel drive works just fine, but after driving for a little bit it slips out of four wheel drive. The lights on the dash still indicate that it is in four wheel drive when it is not. To put it back in four wheel drive, I just have to click the switch over to 2H then back to 4L or 4H. After driving a short distance it will slip again. This happens in 4L and 4H. (in 4L it also slips out of low gear). I am not sure what the problem could be. Does anyone have any ideas?

 

[j.apps]

I have the same thing going on with my truck as well. I can jack the front end up and engage the four wheel drive and the front hubs lock, but when i go to try a brake stand the back tires break loose. After trying that i jack it up again and the hubs are still locked. Hopefully someone knows whats going on???

 

[Earl43P]

Search on "PVH" or "vaccum hubs" or try ....

http://www.therangerstation.com/Magazine/Apr04/offroad.htm or http://www.therangerstation.com/tech_library/AVM_hub_swap.htm or http://www.therangerstation.com/tech_library/99hubswap.htm.

 

[4x4RangerGuy]

Sounds like your vacuum hublocks are malfunctioning. Or it could possibly be the shift motor on the transfer case. Search the site because both of these topics have been covered before and there are plenty of test methods.