Viscous Heater Replacement

REMOVAL
Viscous Heater
1. Drain the engine coolant.
2. Remove the engine accessory drive belt.
3. Remove the heater hose clamps at the Viscous Heater.
4. Remove the heater hoses from the Viscous Heater.
5. Unplug the Viscous Heater clutch electrical connector.
6. Remove the bolts holding the Viscous Heater to the mounting bracket.
7. Remove the Viscous Heater from the vehicle.

Viscous Heater Clutch
1. The viscous heater clutch can be serviced in the vehicle and the cooling system does not have to be drained.
2. Disconnect and isolate the battery negative cable.
3. Remove the serpentine drive belt.
4. Unplug the clutch coil wire harness connector.
5. Remove the bolts that secure the viscous heater to the mounting bracket.
6. Remove the viscous heater from the mounting bracket. Support the viscous heater in the engine compartment while servicing the clutch.

Fig.18 Clutch Nut Remove - Typical:

7. Insert the two pins of the spanner wrench (special Tool C-4489 or equivalent) into the holes of the clutch plate. Hold the clutch plate stationary and remove the hex nut.
8. Remove the clutch plate.
9. Remove the clutch shims.

Fig.19 External Snap Ring Remove - Typical:

10. Remove the external front housing snap ring with snap ring pliers.

Fig.20 Shaft Protector And Puller - Typical:

11. Install the lip of the rotor puller (Special Tool C-6141-1 or equivalent) into the snap ring groove exposed in the previous step, and install the shaft protector (Special Tool C-6141-2 or equivalent).

Fig.21 Install Puller Plate - Typical:

12. Install the puller through bolts (Special Tool C-6461 or equivalent) through the puller flange and into the jaws of the rotor puller and tighten. Turn the puller center bolt clockwise until the rotor is free.
13. Remove the screw and retainer from the clutch coil lead wire harness on the viscous heater housing.

Fig.22 Clutch Field Coil Snap Ring Remove - Typical:

14. Remove the snap ring from the hub and remove the clutch field coil. Slide the clutch field coil off of the hub.

INSTALLATION
Viscous Heater
1. Install Viscous Heater to engine mounting bracket.
2. Install the Viscous Heater mounting bolts and tighten to 33 Nm ( 25 ft. lbs.).
3. Plug the wiring harness electrical connector to the Viscous Heater clutch.
4. Install heater hoses to the Viscous Heater connections.
5. Install heater hose clamps to Viscous Heater connections.
6. Install the engine accessory drive belt.
7. Refill the engine cooling system.
8. Reconnect the battery negative cable.
9. Operate vehicle and check for any coolant leaks, repair as required.

Viscous Heater Clutch
1. Install the clutch field coil and snap ring.
2. Install the screw and retainer on the clutch coil lead wire harness on the viscous heater housing. Tighten the screw to 2.2 Nm (20 in. lbs.).
3. Align the rotor assembly squarely on the front housing hub.
4. Install the rotor bearing assembly with the installer (Special Tool C-687 1 or equivalent). Thread the installer on the shaft, then turn the nut until the rotor assembly is seated.
5. Install the external front housing snap ring with snap ring pliers. The bevel side of the snap ring must be facing outward. Press the snap ring to make sure it is properly seated in the groove.

CAUTION: If the snap ring is not fully seated in the groove it will vibrate out, resulting in a clutch failure and severe damage to the front housing of the compressor.

6. Install the original clutch shims on the shaft.
7. Install the clutch plate. Install the shaft hex nut and tighten to 15-20 Nm (11-15 ft. lbs.).

Fig.23 Check Clutch Air Gap - Typical:

8. Check the clutch air gap with a feeler gauge. If the gap does not meet specification, add or substract shims as required. The air gap specification if 0.41 to 0.79 millimeters (0.016 to 0.031 inches).

NOTE: The air gap is determined by the spacer shims. When installing an original, or a new clutch assembly, try the original shims first. When installing a new clutch (and not having the old shims available) use a 1.0, 0.50 and 0.13 millimeter (0.040, 0.020 and 0.005 inch) shim from the new clutch hardware package that is provided with the new clutch.

9. Reinstall the viscous heater to the mounting bracket. Tighten the mounting screws to 33 Nm (25 ft. lbs.).
10. Reinstall the battery negative cable.