NO. 120 MOTOR GRADER Every 2000 Service Hours Or 1 Year Caterpillar

(38)Rear Axle Housing

1. Remove drain plug located at rear of axle housing. Drain oil.

2. Clean and install drain plug and remove plug in filler opening.

3. Fill to top of filler neck. See Refill Capacities. Clean and install fill plug.

(39)Power Control Shaft Worm And Gear Housing

1. Remove drain plug and drain oil.

2. Clean and install drain plug and remove fill plug.

4. Fill to bottom of level plug opening.

5. Clean and install level plug.

(40)Blade Lift Control Housings

1. Remove drain plugs (one each housing) and allow oil to drain. Clean and install drain plugs.

2. Remove level and fill plugs. Fill to bottom of level plug openings. See Refill Capacities.

3. Clean and install plugs.

(41)Circle Reverse Control Housing

1. Remove drain plug and drain oil.

2. Clean and install drain plug and remove fill plug.

3. Fill to bottom of filler opening. See Refill Capacities.

4. Clean and install fill plug.

(42)Circle Center Shift Control Housing

1. Remove drain plug and drain oil.

2. Clean and install drain plug and remove fill plug.

3. Fill to bottom of filler opening. See Refill Capacities.

4. Clean and install fill plug.

(43)Power Control Housing

1. Remove drain plug and drain oil.

2. Clean and install drain plug and remove fill plug.

3. Remove level plug.

4. Fill to bottom of level plug opening.

5. Clean and install level plug.

6. Clean and install fill plug.

(44)Tandem Drive Housings

1. Remove 1 drain plug from each side. Allow to drain.

2. Install drain plugs and remove breather-plunger gauge - filler cap.

3. Fill to full mark on plunger gauge. See Refill Capacities.

4. Install gauge.

(45)Hydraulic Control System

1. Park machine on level ground. Lower all raised equipment and stop engine.

2. Remove filler cap to relieve pressure.

3. Remove drain hole cover and allow to drain.

4. Change filter element. See item 28.

5. Clean and install drain hole cover.

6. Fill tank to top of filler neck. See Refill Capacities. Put cap on loosely.

7. Start engine and run for 2 minutes. Stop engine and check oil level.

(46)Transmission And Flywheel Clutch

1. Park machine on level ground and stop engine.

2. Remove drain plugs and allow oil to drain.

3. Remove magnetic strainer housing drain plug and allow to drain.

4. Change filter element. See item 27.

5. Wash and oil breathers. See item 32.

6. Remove screen cover.

7. Remove screen.

8. Wash screen and cover in clean solvent.

9. Check cover seal. Use new seal if necessary.

10. Install screen and cover.

11. Remove cover.

12. Remove tube and screen.

13. Separate tube and screen.

14. Clean tube, magnets and screen in clean solvent. Use a clean cloth, pressure air or a stiff fiber brush to remove metal particles.

NOTE: Do not drop or rap magnets hard against hard objects.

Show/hide table

When using pressure air, wear safety glasses and protective clothing.

15. Install tube and magnets into screen (small end first).

16. Check cover seal and use new one if necessary.

17. Install tube and screen.

18. Clean and install drain plugs.

19. Fill transmission. See Refill Capacities. Operate machine a few minutes and recheck oil level.

(47)Front Wheel Bearings

1. Raise front wheels and block under axle.

2. Remove hub cap bolts and cap.

3. Remove cotter pin from locking pin and remove pin.

4. Remove axle nut.

5. Remove washer.

6. Slide wheel out and back to free outer bearing. Remove bearing.

7. Remove wheel from axle using a sling and hoist.

8. Clean axle and inner bearings. Inspect bearing.

9. Clean wheel bearing, washer, pin and nut. Inspect bearings.

10. Inspect grease seal. Use new seal if necessary.

11. Inspect nut to make sure threads are in good condition.

12. Clean bearing surface and cavity.

13. Pack grease on and in axle bearing.

14. Pack grease in wheel cavity.

15. Install wheel on axle.

16. Pack grease on and in wheel bearing and install bearing.

17. Install washer and nut. Make certain bearing has plenty of grease.

18. Rotate wheel and tighten nut until bearing seizes.

19. Back nut off one slot. Wheel must rotate freely with no side play.

20. Install nut locking pin.

21. Install cotter pin.

22. Install hub cap and bolts.

(48)Circle Drawbar Ball And Socket

1. Raise blade off ground and pry drawbar forward as far as possible.

2. Measure clearance between drawbar ball and cap. Clearance should not be over .062 inch (1,57 mm).

3. To adjust, remove cap bolts and slide cap back.

4. Cut shim or shims, as required and remove.

5. Install and tighten cap bolts.

6. Check clearance. Repeat steps 3, 4 and 5 if clearance is over .062 inch (1,57 mm).

(49)Engine Valve Lash

1. Engine must be stopped. Remove valve cover.

Valve location guide and clearance specifications.

2. Remove plug from left rear of flywheel housing.

3. Turn flywheel slowly to close No. 1 exhaust and inlet valves and allow timing bolt (L2070) to be installed in flywheel. Do not use starting motor to turn flywheel.

4. Check lash of No. 1, No. 3 and No. 5 exhaust valves. Check lash of No. 1, No. 2 and No. 4 inlet valves. Adjust if necessary (see page 31).

5. Remove bolt from flywheel.

6. Turn flywheel 360° to close No. 6 exhaust and inlet valves. Insert bolt.

7. Check lash of No. 2, No. 4 and No. 6 exhaust valves. Check lash of No. 3, No. 5 and No. 6 inlet valves. Adjust if necessary.

8. Remove bolt from flywheel.

9. Install plug in flywheel housing.

10. Start engine and run at low idle. Check valve rotators. If valves do not rotate, see your AVSpare dealer.

11. Stop engine and install valve cover.

12. Tighten valve cover bolts to 6 to 10 lb. ft. (0,83 to 1,39 mkg) in the sequence shown.

Adjusting Valve Lash:

1. Loosen adjusting screw locknut.

2. Turn adjusting screw clockwise to close gap and counterclockwise to open gap. See page 29 for correct lash setting.

3. Check adjustment.

4. Hold adjusting screw with a screwdriver and tighten locknut.

5. Recheck adjustment.

6. Remove bolt from flywheel and install plug in flywheel housing.

7. Install rocker arm cover and follow bolt tightening sequence and torque.