641B & 651B TRACTOR-SCRAPERS Every 2000 Service Hours Or 1 Year Caterpillar

Every 2000 Service Hours Or 1 Year
1.1. (24)Engine Valve Lash
2.1. (24a)Scraper Wheel Bearings
3.1. (25)Cooling System - Changing Antifreeze Solution<SUP><FONT SIZE=-1>(1)</FONT></SUP>
4.1. (26)Hydraulic System
5.1. (27)Differential And Final Drives
6.1. (28)Ejector Guide Rollers - (641)
7.1. (29)Ejector Carrier Rollers
8.1. (30)Steering Gear Housing And Lower Bearing
9.1. (31)Steering Column Shaft
10.1. (32)Instrument Panel Bracket
11.1. (33)Drive Shaft Universals
12.1. (34)Operator's Seat

(24)Engine Valve Lash

See 641 and 651 TRACTOR SCRAPER SERVICE MANUAL for correct valve adjustment procedure. Use AVSpare Part No. 5P7307 Engine Turning Tool to turn the flywheel.

Resetting valve lash is not required if lash measured is within .003 inch (0.08 mm) of the lash shown.

(24a)Scraper Wheel Bearings

1. Remove the plug at each scraper wheel.
2. Maintain the lubricant level to the bottom of the plug opening.
3. Clean and install the plugs.

(25)Cooling System - Changing Antifreeze Solution(1)

NOTE: When permanent antifreeze and water solutions are used in the cooling system, the solution should be drained and replaced every 2000 hours, or yearly.

When additions of inhibitor are made to the cooling system every 500 hours, or three months, it is not necessary to drain and refill yearly.

Use clean water that is low in scale forming minerals - not softened water.

Check specific gravity of antifreeze solution frequently in cold weather to assure adequate protection.

Add AVSpare Corrosion Inhibitor. Follow recommendations given on container.

------ WARNING! ------

Inhibitor contains alkali, avoid contact with skin and eyes.


NOTE: The engine cooling system is protected to -20°F (-29°C), with permanent-type antifreeze, when shipped from the factory.

1. The machine must be level. The bowl must be lowered. Apply the parking brake. Stop the engine.

2. Turn filler cap slowly to relieve pressure, then remove cap.

3. Open radiator drain valve and allow coolant to drain.
4. Remove drain plug from orake oil cooler.
5. Remove drain plug from engine oil cooler.
6. Close radiator drain valve.
7. Clean and install all drain plugs.
8. Mix antifreeze solution to provide protection to the lowest expected ambient temperature.
9. Add antifreeze solution. See REFILL CAPACITIES.
10. Install filler cap.

(1)If machine is to be stored in or shipped to an area with below freezing temperatures, the cooling system must be drained completely or protected to lowest expected ambient temperature.

(26)Hydraulic System


Machine level, bowl lowered, ejector forward, parking brake set, oil warm, and engines stopped.

Move hydraulic controls to help relieve pressure.

1. Remove tank filler cap slowly to relieve pressure.

2. Remove hydraulic tank drain plug.

3. Open drain valve and allow oil to drain.
4. Change hydraulic filter elements. See Item 18.
5. Close tank drain valve. Clean and install drain plug.

6. Remove tank filler screen. Wash screen in clean solvent.
7. Shake or blow dry.

------ WARNING! ------

When using pressure air, wear safety glasses and protective clothing. Use 30 PSI (2 kg/cm2) maximum pressure air for cleaning purposes.

8. Install screen in tank.

9. Fill tank. See REFILL CAPACITIES. Start engine and allow oil to circulate.

10. Stop engine and check oil level. Add oil if necessary.

(27)Differential And Final Drives


Machine level, scraper lowered, parking brake set, differential and final drive lubricant warm and engine stopped.

1. Position wheels so final drive drain plugs are at lowest point. Remove drain plugs.

2. Remove differential drain plug and allow lubricant to drain.
3. Clean all drain plugs.
4. Install drain plugs in differential and final drives when completely drained.

5. Fill differential and final drives.

6. To speed filling, add lubricant at final drives. Position wheels so drain plugs are at bottom.
7. Remove final drive fill plugs.
8. Fill at differential and final drives until correct amount of lubricant has been used. See REFILL CAPACITIES.

9. Check lubricant level after a short period of operation, and add lubricant if necessary.

NOTE: Check lubricant level frequently if any sign of leakage develops or is suspected.

(28)Ejector Guide Rollers - (641)

1. Remove cover.

2. Remove locknut, lock, washer and upper bearing.
3. Pack roller cavity with grease.

4. Install upper bearing, washer lock and locknut. Make sure bearing is thoroughly packed.

5. Tighten locknut until roller locks, then back nut off 1/6 turn.

NOTE: Bearings are properly adjusted when roller turns freely without end play.

6. Crimp lock against locknut.
7. Pack with grease and install cap.

NOTE: For roller to side sheet adjustment, see Item 40.

(29)Ejector Carrier Rollers

1. Raise and block ejector to relieve weight on carrier roller.

2. Remove cap.

3. Remove nut, lock, washer and outer bearing.
4. Pack roller cavity with grease.
5. Install outer bearing, washer, lock and nut.

6. Tighten nut until roller locks, then back nut off 1/6 turn.

NOTE: Bearings are properly adjusted when roller turns freely without end play.

7. Pack with grease and install cap.

NOTE: For roller height adjustment. See Item 41.

(30)Steering Gear Housing And Lower Bearing

1. Remove filler plug. Maintain oil level to plug opening. Clean and install plug.

2. Remove plug. Lubricate with 2 or 3 squirts of oil. Clean and install plug.

(31)Steering Column Shaft

Lubricate 1 fitting.

(32)Instrument Panel Bracket

Lubricate 1 fitting.

(33)Drive Shaft Universals

Lubricate 2 fittings.

(34)Operator's Seat

Lubricate 3 fittings.