Compressor Clutch: Service and Repair

REMOVAL

NOTE: Compressor assembly must be removed from mounting. Although, refrigerant discharge is not necessary.

Compressor Shaft Bolt And Clutch Plate:

1. Remove the compressor shaft bolt. A band type oil filter removal tool can be placed around the clutch plate to aid in bolt removal.

Clutch Plate And Shims:

2. Tap the clutch plate with a plastic hammer and remove clutch plate and shim(s).

CAUTION: Do not use screwdrivers between the clutch plate assembly and pulley to remove front plate as this may damage the front plate assembly.

Removing Pulley Snap Ring:

3. Remove pulley retaining snap ring with Snap Ring Pliers (C-4574), and slide pulley assembly off of compressor.
4. Remove coil wire bracket/ground clip screw and wire harness.

Clutch Coil Snap Ring:

5. Remove snap ring retaining field coil onto compressor housing. Slide field coil off of compressor housing.
6. Examine frictional faces of the clutch pulley and front plate for wear. The pulley and front plate should be replaced if there is excessive wear or scoring. If the friction surfaces are oily, inspect the shaft nose area of the compressor for oil and remove the felt from the front cover. If the compressor felt is saturated with oil, the shaft seal is leaking and will have to be replaced.
7. Check bearing for roughness or excessive leakage of grease. Replace bearing as required.

INSTALLATION
1. Align pin in back of field coil with hole in compressor end housing, and position field coil into place. Make sure that lead wires are properly routed, and fasten the diode and coil wire bracket with retaining screw.
2. Install field coil retaining snap ring with Snap Ring Pliers (C- 4574). Press snap ring to make sure it is properly seated in the groove.

NOTE: The bevel side of the snap ring must be outward. Also both eyelets must be to the right or left of the pin on the compressor.

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

CAUTION: Do not mar the pulley frictional surface.

Installing Pulley Assembly:

3. Install pulley assembly to compressor. If necessary, tap gently with a block of wood on the friction surface.
4. Install pulley assembly retaining snap ring (bevel side outward) with Snap Ring Pliers (C-4574). Press the snap ring to make sure it is properly seated in the groove.

NOTE: The bevel side of the snap ring must be facing outward.

5. If the original front plate assembly and pulley assembly are to be reused, the old shim(s) can be used. If not, place a trial stack of shims, 2.54 mm (0.10 in.) thick, on the shaft against the shoulder.
6. Install front plate assembly onto shaft.
7. If installing a new front plate and/or pulley assembly, the gap between front plate and pulley face must be checked. Use the following procedure:
- Attach a dial indicator to front plate so that movement of the plate can be measured.
- With the dial indicator zeroed on the front plate, energize the clutch and record the amount of movement.
- The readings should be 0.35 to 0.65 mm (0.014 to 0.026 in.). If proper reading is not obtained, add or subtract shims until desired reading is obtained.
8. Install compressor shaft bolt. Tighten to 15.5 to 19.5 N.m (135 to 175 in. lbs.).

NOTE: Shims may compress after tightening shaft nut. Check air gap in four or more places to verify if air gap is still correct. Spin pulley for final check.

CLUTCH BREAK-IN
After new clutch installation, cycle the A/C clutch 20 times (5 seconds ON and 5 seconds OFF). During this procedure, set the system to the A/C mode, engine rpm at 1500-2000, and high blower speed. This procedure (burnishing) will seat the opposing friction surfaces and provide a higher clutch torque capability.

NOTE: Excessive clutch gap will result in clutch slippage or non-engagement.