Description And Operation

The MP1622C transfer case is the heart of the Command-Trac™ and Rock-Trac™ part-time 4WD system. When engaged in 4WD, both front and rear drive shafts are locked by a chain and gearset, which always turn at the same speed, forming a single drive unit. This is a rigid connection that does not allow for any differential action between front and rear drive shafts. Normal front-to-rear differences in the turning radii of the wheels (when cornering) are compensated for only through wheel slippage on driving surfaces. This transfer case allows for 2WD, 4WD High-Range and Low-Range as well as Neutral.

The MP1622 provides the following ranges through a mechanical shifter:

• 2WD HIGH:
  • Front axle spins freely.
  • Power sent to rear wheel.
  • A synchronizer inside the transfer case makes for smoother shifts between 2HI - 4HI and for the Front Axle Disconnect (FAD) Feature
• 4WD HIGH:
  • Shift-on-the-Fly at speeds up to 88 km/h (55 mph). Shift Efforts may increase as vehicle speed increases, due to the need for synchronization.
  • Front and rear drive shafts lock together and rotate at the same speed.
  • Only use on slippery or loose surfaces.
• NEUTRAL:
  • Use for towing your vehicle behind another vehicle.
  • The vehicle may roll while the transfer case is in neutral, even with the transmission in park
  • Does not require uncoupling drive shafts.
• 4WD LOW:
  • Use for severe off-road situations.
  • Increases available engine torque by 2.72:1 (4:1 in Rock-Trac™ equipped vehicles).
  • Slow speed to 3-5 km/h (2-3 mph), put transmission in Neutral, engage 4 LO and return transmission to desired gear.