Stuck in low

[dan n]

Hello all I'm back on TRS after being away for a couple of years. Just bought me another ranger after selling my 96 a couple of years ago. (Really missed my Ranger) I now have a 05 4x4 4.0 automatic. nice truck with low miles. One problem i had with it was it got stuck in 4 wheel low. I was able to get it unstuck after about 15 minutes of screwing with it. It has the switch on the dash that switches between 2 wheel, 4 high and low
any ideas on what the problem can be? or where i should start looking at.

Thanks

 

[RonD]

Shift Motor would be the first stop

You should shift into 4high then 4low and back to 2WD once a month, just sitting in the driveway, you don't have to move the vehicle.
What that does is to keep the electric motor contacts clean.
Often if it stops working you can "tap" on the motor to get it to move again, this gets the motors brushes, which get stuck, to touch rotor again and motor can get power.

A 2004 Ranger will use a separate 4x4 module to control the shift motor, and these did fail, not a common issue but not unheard of either.

Shift motor is the only "moving" part in the system except for the Relays in the 4x4 module.
Shift motor is a DC motor so the direction it will turn the transfer case shift rod is determined by polarity, + and - applied to the 2 motor wires, the 2 relays in the 4x4 module do this polarity change.

Shift motor set at 2WD will have to turn 90deg counter clockwise to get to 4high, then another 90deg to get to Neutral(yes there is a Neutral, you just can't select it )
Then another 90deg counter clockwise to get to 4low
So 2WD to 4low is 270deg rotation counter clockwise, same polarity on motor.
To go back to 2WD, or 4high, from 4low you have to Reverse the motors polarity, so it moves Clockwise, 180deg to 4high or 270deg to 2WD

1 relay in the 4x4 module could go bad so motor only move counter clockwise, so you would get stuck in 4low, but it wouldn't be likely to start working again.

The 5 "extra wires" on the shift motor are for a contact wheel inside the gear drive of the shift motor, these contacts "tell" the 4x4 module when it gets to 4high, 4low or 2WD positions, this is adjustable somewhat by slotted bolt holes

 

[dan n]

Thanks RonD for the reply, very helpful. I will try to exercise the motor and hope it will take care of itself. The person that owned the truck before me may
have not used 4 low to often.

Thanks again

 

[85_Ranger4x4]

And if you get in a bind you can remove the shift motor and shift the t-case manually with pliers or a wrench on the shaft that the shift motor engages. The t-case is marked where the different positions are.