Here's a breakdown of how it likely works:
* Low Range (4L): This is for very low speed, high-torque situations like mud, snow, or steep inclines. It significantly reduces speed for increased power. You should *only* use this at low speeds and off-road.
* High Range (4H): This is for driving on loose surfaces, like gravel or snow. It's not intended for use on dry paved roads.
* 2 Wheel Drive (2H or 2WD): This is for normal driving on paved roads.
The Exact Engagement Process:
You'll need to consult your owner's manual (if you have it) for the precise steps. However, the general process is as follows:
1. Bring the vehicle to a complete stop. Engaging 4WD while moving can damage the drivetrain.
2. Shift the transfer case shifter: This shifter will usually have positions for 2H (2-wheel drive high), 4H (4-wheel drive high), and 4L (4-wheel drive low). Shift into the desired position.
3. (If applicable) Engage locking hubs: Some 1988 Rangers used manual locking hubs. These are located on the front wheel axles. You'll need to manually lock them before engaging 4WD high or low. The hubs will have a lever or a knob to turn them from "free" to "locked."
Important Considerations:
* Driving on Paved Roads: Avoid driving in 4H or 4L on paved roads. It can lead to drivetrain damage and premature tire wear.
* Speed Limits: Use 4H at moderate speeds. Never use 4L above 20-25 mph.
* Turning: Avoid sharp turns at low speeds while in 4WD, as this can cause binding.
Without your owner's manual, it's difficult to give precise instructions. Finding a manual online (e.g., via a Ford parts website or a repair manual provider) is strongly recommended for safety and to avoid damaging your vehicle. The manual will have diagrams and explicit instructions specific to your truck's 4WD system.
