I recently discovered a problem with my trucks 4WD. I drive an automatic Ford Ranger which switches from 2WD into 4WD high and low on the fly. When I switch to 4WD high I can hear it switch and the light turns on on my dash. When I switch to 4WD low no light turns on. However when I am in 4WD high the front tires wont rotate, I was recently stuck in a very small snowbank (less than .5 ft!) on a slight incline and even in 4WD my front tires would not rotate at all! What is going on?
Were you moving when you switched, or were you stuck already? What year is the Ranger? Older models, like my 95, used cam-locks to rock into the locked position. Slightly newer used vacuum. Most recently, I think, the front axles are always locked. The light goes on when the transfer case switches to 4x and the axles “try” to lock, there is no indication if they do or don’t. Except for very recent models, you have to be moving to get the axles to lock “on the fly.”
I would suspect you aren’t moving, or that you have the vacuum model and it is not working or you have a leak.
On my 95 I put in manual lockers when one of my auto-locking hubs ate itself. It was cheaper for 2 manuals than to replace one auto.
reply 1
Sounds like a hub problem.
What year it the ranger ?
Vacuum hubs or mechanical ?
The light gets its signal from a switch on the transfer case which sounds like IT is working.
With the truck up on a hoist see if the front drive shaft is turning.
The ranger is a 99. I was already in 4WD high before I got stuck. I was trying to go up a slight incline and just slarted slowly sliding off the road and couldent get the tires to engage. Once I was stuck I still couldent get them engaged I tried switching in and out of 4WD and neutral but couldent get any rotation. After I got pulled out and was on flat (non snow covered) ground I tried swithing while moving and could hear the ‘Thunk’ of the 4WD engaging.
The ranger is a 99, I am not sure the type of hub? When I switch in a out of the 4wd on the fly I can hear it thunk and engage!
reply 2
Still sounds like a front axle vacuum issue. ( this model doesn’t have free wheeling hubs )
The thunk is the transfer case working normally.
The 99 has a vacuum motor and shift fork in the front differential housing ( to free both front wheels ), vacuum solenoids under the right front fender, and many vacuum tubes connecting all of the above.
Start checking / proving your 4x4 vacuum system.
On a truck this age check every inch af the vacuum lines/tubes. They are just plastic and a vacuum leak is the step one guess here.
The vacuum shift motor will be the next most common area of vacuum leak.
It could be something else as well, like electrical to the solenoids or the front axle internal shift fork, but start with vacuum issues.
see reply 2 above.