Viscous Coupler

NOTE: The heart of the all-wheel drive system is the inter-axle viscous coupler. Under normal driving the vehicle retains predominantly front wheel drive characteristics. The all-wheel drive takes effect when the front wheels start to slip. Under normal level road, straight line driving, 90% of the torque is allocated to the front wheels. The viscous coupler allows more torque to the rear wheels in accordance with the amount of slippage at the front wheels. The variable torque distribution is automatic with no driver inputs required.

REMOVAL
1. Hoist vehicle.
2. Mark flange at propeller shaft and viscous coupler for reference.
3. Install a thin 1-1/4 inch open-end (Snap-On LTA4042 or equivalent) wrench behind the viscous coupler. Slip the wrench onto the flats of the torque shaft.





4. Remove bolts at propeller shaft flange.





5. Remove shaft from coupler and secure shaft to underbody. Do not let the propeller shaft hang freely, damage may occur





6. Hold the torque shaft from turning. Remove viscous coupler retaining nut.





7. Slide coupler off torque shaft.

INSTALLATION
1. Slide viscous coupler onto torque shaft.
2. Install a thin 1-1/4 inch open-end (Snap-On LTA4042 or equivalent) wrench onto the flats of the torque shaft. Install NEW viscous coupler retaining nut. Tighten retaining nut to 244 Nm (180 ft. lbs.).
3. Detach the propeller shaft from support strap.
4. Position propeller shaft at the reference marks.





5. Install propeller shaft bolts. Tighten bolts to 28 Nm (250 inch lbs.).