407914-1880 ZEXEL 9 443 612 678 BOSCH CONTROL UNIT 9443612678 4079141880

START BY:a. remove timing gear cover
Do not disconnect the air line from the air compressor governor until the air pressure is zero.
1. Loosen the bleed valves, and release the air pressure in the air tank. 2. Disconnect the lines from air compressor (1), and remove the air compressor. 3. Remove sleeve (2) from air compressor drive gear (3). 4. Remove the nut and washer that holds the air compressor drive gear to the air compressor. Use tooling (A) to remove air compressor drive gear (3) from the air compressor. 5. Remove nuts (4) and plate (5). Remove gear assembly (6) from the shaft. 6. If damaged, remove bearing (7) from gear (6) with tooling (B) and a press. 7. Remove three nuts (8) and the washers from the adapter assembly studs. 8. Remove adapter assembly (9) from the timing gear plate. 9. Remove shaft (10), O-ring seal (11) and sleeve (12) from the adapter assembly.Install Air Compressor And Accessory Drive
1. Install sleeve (1) into adapter assembly (2). 2. Install shaft (3) and O-ring seal (4) on the adapter assembly. 3. Put adapter assembly (2) in position on the timing gear plate. Fasten it with the three nuts and washers. 4. Install the bearing in gear (5) with tooling (A) and a press. Install the bearing until it is 1.5 0.5 mm (.06 .02 in.) below the surface of the gear as shown. 5. Put gear assembly (5) in position on shaft (3). 6. Put plate (6) in position, and install three nuts (7) to hold it. 7. Put gear (8) in position on the air compressor shaft, and install the washer and nut (9). Tighten the nut to a torque of 200 25 N m (150 18 lb.in.). Tap the gear with a hammer and tighten nut (9) again to a torque of 200 25 N m (150 18 lb.ft.). 8. Install sleeve (10) on gear (8). 9. Put a gasket in position on air compressor (11), and install the air compressor on the timing cover plate.END BY:a. install timing gear cover