Section III. GENERAL MAINTENANCE INSTRUCTIONS

TM 9-2320-363-34-1 · Chapter 2 — Direct and General Support Maintenance Instructions

This section describes general maintenance instructions that apply to all parts of this manual. To avoid repetition, these procedures will not be described in specific maintenance sections.

1. Work Required. Remove only those parts needing repair or replacement. Do not disassemble a component any further than needed.

2. Preparation. Before removing any part of the electrical, hydraulic, or air systems, make certain system is not energized or pressurized. Disconnect battery cables. Relieve all pressure from air system. Make sure brakes are locked and that all controls are in OFF position before starling any removal procedure.

3. Removal. Make sure there is enough clearance to remove part. Disassemble adjacent parts as needed to provide working clearance.

4. Lifting. Always use chain hoist, jack, or other aid when lifting heavy parts. Make certain load limit of lifting device exceeds weight being lifted. Position and rig lifting device before disconnecting part for removal.

5. Identification. Tag or mark all similar parts, such as electrical leads, before disconnecting and removing such parts. This will make proper assembly easier. Be sure to identify mating ‘ends of electric lines, hydraulic lines, and air tubes as they are disconnected.

6. Position of Valves. Before removing valve handles, mark or diagram their positions when open and closed. This will help during assembly,

1. Cleanliness. Work area must be kept as clean as possible. This will prevent injury or contamination of internal parts. This is especially true for valves, cylinders, and other hydraulic or air system parts.

2. Expendable Pads. As indicated in this manual, all gaskets, packings, and seals removed during repair must be discarded and replaced with new parts. These items are usually damaged during removal. In the same way, all Iockwire, cotter pins, and like items must be replaced at time of assembly.

3. Removing Seals. When removing gaskets, packings, or seals, do not use any metal tool that will scratch the surfaces next to these items.

4. Disassembly. Before disassembly of any item, study the illustration carefully. Note relationship of internal parts. Knowing details of a component will speed up disassembly and assembly and will help avoid mistakes.

5. Parts Protection. To prevent moisture and dirt from entering open housings, lines, and other openings, apply protective caps and plugs as soon as possible after disassembly. Wrap all removed parts in clean paper or dip parts in preservative oil.

1. Cleaning Solvents. Use only approved cleaning solvents to clean parts. Drycleaning solvent SD-2 is commonly used. Always work in a well-ventilated area.

To prevent injury, compressed air will not exceed 30 psi (207 kPa). Use only with effective chip guarding and personal protective equipment (goggles/shield, gloves, etc.).

2. Removing Deposits. After soaking parts in solvent, wash away deposits by flushing or spraying. Where necessary, brush with a soft-bristle brush moistened in solvent. Use compressed air to dry all parts, except bearings. Bearings must be allowed to air dry.

3. Tools. Do not use abrasive wheels, or compounds in cleaning parts, unless called for in detailed instructions. These procedures may weaken a highly stressed part.

4. Ball and Roller Bearings. When cleaning ball or roller bearings, place them in a basket and suspend them in a container of drycleaning solvent. If needed, use a brush to remove bearing before solid particles are removed to prevent damaging races and balls. When bearings have been cleaned, coat them lightly with lubricating oil to remove solvent. Refer to TM 9-214 for additional instructions on cleaning bearings.

5. Rubber Parts. Do not clean O-rings or other rubber parts in drycleaning solvent. Clean by washing with a mild solution of soap and water. Wipe with a clean, dry, lint-free cloth.

Steam cleaning creates hazardous noise levels and severe burn potential. Eye, skin, and ear protection are required.

6. Exterior Parts. Steam clean all exterior parts thoroughly before removing. This will make inspection and disassembly easier.

7. Engine, Cab, and Body. Use a spray gun and solvent mixture for cleaning exterior of engine, cab, and body. Allow mixture to remain on item surface for about 10 minutes before rinsing. Rinse with hot water under 80-120 pounds of pressure, if available. An ordinary garden hose with nozzle may be used if other equipment is not available. Rinse thoroughly.

8. Decreasing Machine. A decreasing machine may be used to remove heavy grease and oil accumulations from metal parts.

9. Passages. After removing parts from decreasing machine, and before coating with rust preventive, check all oil passages and cavities for dirt or blockage. A thin, flexible wire should be run through oil passages to make certain they are not clogged. Individual passages that are dirty may be cleared using a pressure spray gun and drycleaning solvent.

10. Electrical Parts. Electrical parts, such as coils, junction blocks, switches, and igniters, which use insulating materials, should not be soaked or sprayed with cleaning solutions. Clean these parts with a clean, lint-free cloth moistened with drycleaning solvent.

11. Electrical Grounds. Clean electrical ground contacts with crocus cloth.

12. Oil and Fuel Tank. Pay special attention to all warnings and cautions when working on vehicle’s fuel tank. Oil tanks and fuel tanks should be flushed, using a spray gun and drycleaning solvent.

13. Battery. Exterior surfaces of the electrical system and battery should be cleaned with a weak solution of baking soda and water. Apply solution with a bristle brush to remove any corrosion.

14. Hydraulic System. When cleaning hydraulic system pacts, use drycleaning solvent SD-2. Clean and dry parts thoroughly to make sure no residue remains. If a coating of preservative is required before assembly, apply a light film of preservative oil. If petroleum-free solvents are not available, use the same hydraulic fluid as used in the hydraulic system.

1. Sealing Surfaces. Inspect all surfaces in contact with gaskets, packings, or seals. Make sure there are no nicks, burrs, or scratches. If any defect is found, remove or repair it as outlined under General Repair Instructions in this chapter.

2. Bearings. Check bearings for rusted or pitted balls, races, or separators, Check balls and races for brinnelling, abrasion, and serious discoloration. Refer to TM 9-214 for additional instructions for bearings. Following are causes for bearing rejection:

Cuts or grooves parallel to ball or roller rotation. Fatigue pits (not minor machine marks or scratches). Cracks.

3. Inspection. Inspection consists of checking for defects such as distortion, wear, cracks, and pitting. Parts under heavy load or pressure must be inspected more thoroughly. Clean all parts before inspection.

4. Drain Plugs. When removing drain plugs from transmission, engine, or hydraulic system components, inspect sediment adhering to plug. A buildup of grit and/or fine metal particles may indicate part failure. A few fine particles are normal. This inspection is effective in determining defective parts prior to internal inspection of parts.

5. Gears. Gear inspection cannot be described in detail here; there are too many differences in size and shape of gears. The following steps can be used to make a general visual inspection of all gears. Follow all steps listed in General Repair Instructions for final inspection.

Normal Wear. Loss of metal from the surface of gear teeth. Wear must not prevent gears from meshing or performing properly. Initial Pitting. This may occur when a pair of gears is first started in service. It may continue until most high spots have been reduced, as long as contact surfaces are not affected. This pitting is not necessarily serious. Destructive Pitting. This type of pitting occurs after initial pitting, often at an increasing rate. This will destroy contact area and reduce the gear’s ability to carry a load. Rapid destruction will occur with use.

l Abrasive Wear. This damage is caused by the fine particles that may come from many sources: metal detached from gear teeth or bearings, abrasives not completely removed before assembly, sand or scale from castings, or other impurities in oil or air. l Scoring. Slight scoring, scuffing, galling, or other surface damage is identified by tears or scratches in the direction of sliding. It starts in areas having the highest stress and speed. This is usually at the tip of the teeth. l Burning. Burning is indicated by discoloration and loss of hardness due to excessive temperature. This is caused by too much friction resulting from overload, overspeed, lack of backlash, or faulty lubrication. if discoloring can be wiped off with clean cloth, such discoloring usually can be traced to oilburn-trains, which are not serious. l Roiling. This damage occurs mainly on plastic gears. Roiling is when material is pushed out of shape without breaking off. This is caused by heavy, even loads; sliding; or overheating. l Brinelling. This can be identified by tiny indentations or ridges on the shoulder or race of a bearing.

6. Splines. inspect shaft splines for wear, pitting, rolling, peening, and fatigue cracks. In many cases, the same inspection procedure will apply to gears. However, the problem, if present, will often be much less pronounced. Have a magnetic particle inspection performed on splines, if needed.

7. Tubes and Hoses. Check all hose surfaces for broken or frayed fabric. Check for breaks caused by sharp kinks or rubbing against other parts of the truck. Inspect air tubes for kinks. inspect the fitting threads for damage. Replace any part found defective. Following assembly and during initial operation, check for leaks.

8. Electrical Parts. inspect all wiring harnesses for chafed or burned insulation. Inspect all terminal connectors for loose connections and broken parts.

9. Metal Parts. Visually inspect ail castings and weldments for cracks. Paris that carry a great load should receive magnetic particle inspection. Critical nonferrous parts may be inspected with fluorescent penetrant.

1. Burrs. Remove burrs from gear teeth with a fine-cut file or hand grinder. Remove burrs on closely fitted mating surfaces by lapping the surfaces with abrasive-grade compound.

2. Exterior Parts. Chassis and exterior painted parts may be resurfaced where paint is damaged, or where parts have been repaired, by using an abrasive disc driven by a flexible shaft. Paint metal surfaces as required per TM-9-2320-363-10.

3. Bearings. Remove residue and oil stain from bearing races with crocus cloth.

4. Protective Parts. During repair operations, protect bare steel surfaces from rusting when not actually undergoing repair work. Dip parts in, or spray them with, corrosion preventive compound. The same protective coating may be applied to other metals to prevent rust. Aluminum parts may require protection in atmospheres having a high salt content. Steel parts must always be protected.

Before welding, the following components must be disconnected: DDEC ECU, ABS ECU, CTIS ECU, DATALOGGER, and batteries (TM 9-2320-363-20-2). If welding on a trailer, it must be uncoupled from tractor/dump truck. Failure to follow this caution may damage electronic components.

5. Welding. Welding and brazing may be used to repair cracks in external steel parts, such as brackets, panels, and light framework. These repairs should be made only when replacement parts are not available. Do not weld or braze castings, running parts, or parts under great stress, except in emergencies. When welding is required, refer to TM 9-237.

6. Stud Installation. When installing studs in engine block and axle housings, use a driver designed for the stud to be installed. A worn stud driver may damage the end thread. This makes it necessary to use a chasing die before a nut can be screwed on. This procedure will remove cadmium plating and allow corrosion, which will make future disassembly difficult and cause stud to be backed out with nut. Before driving a stud, inspect hole for chips and liquid. Blow out any foreign matter. Start stud by hand. If it will not start into hole, it is too large or has defective end thread. Before final insertion, coat thread with antiseize compound; turn stud in slowly to prevent overheating and galling of casting metal.

7. Electrical Parts. Replace all broken, worn, or burned electrical wiring. Wires with several broken strands must be replaced. Broken strands will increase the resistance of the wire and impair efficiency of electrical components, especially the ignition system.

8. Hoses. Replace all broken, frayed, crimped, or soft flexible lines and hoses. Replace stripped or damaged fittings. Replace entire flexible hose if fittings are damaged. Make sure hose clamps do not crimp hoses.

9 Fasteners. Replace any bolt, screw, nut, or fitting with damaged threads. Inspect tapped holes for thread damage. If cross-threading or galling is evident. retap the holes for the next oversize screw or stud. When retapping will weaken the part, or when the cost of the part makes retapping impractical, replace the damaged part. Chasing threads with the proper size tap or die may often be enough.

10. Dents. Straighten minor body dents by bumping with a soft-faced hammer while uslng a wooden block backing.

11. Sheet Metal Repair. Repair minor skin cracks by installing patches.

12. Mounting Holes. Reshape oval mounting holes to round. Drill to receive bushing with required inner diameter. Stake bushing in place with center punch.

1, Preparation. Remove grease from new parts before installation.

2. Packing Installation. Lubricate ail packings with a thin coating of light mineral oil before installation. Slightly stretch packing and place into position. Rotate component on flat surface or uniformly press the packing into position.

3. Pipe Joints. Use nonhardening pipe-joint compound or thread sealing tape when joining piping.

4. Gaskets. To provide added sealing for gasket, coat both sides with sealant. Remove all traces of previous gasket and sealant before installing new gasket.

5. Silicone Sealant.

Silicone sealant is often used instead of a gasket to seal mating parts. Mating parts must be clean, dry, and free of oil or grease for proper adhesion. After silicone sealant has been applied, mating parts must be assembled within 15 minutes. Silicone sealant starts to set up in 15 minutes and takes 24 hours to completely cure. Excess silicone sealant should be wiped off after assembling mating parts.

6. Oil Seals. install oil seals with seal lip facing toward lubricant, applying an even force to outer edge of seal. Coat oil seals evenly with grease before installing. If oil seals will be installed over keyed or splined shafts, use a guide. This will prevent sharp edge of keyway or splines from cutting the leather or neoprene seal. Construct guides of very thin-gage sheet metal and shape to required diameter. However, make certain guide edges are not sharp. Bend them sightly inward so they do not cut the seal.

7. Seal Rings. Coat seal rings with oil and carefully install into their bores. If seal rings must be installed over threaded parts, temporarily wrap the threads with tape to protect the seal ring; then remove the tape.

8. Bearings and Shafts. During assembly of shafts and bearings in housings, first mount bearing on shaft, then install the assembly by applying force to shaft. When mounting bearings on shafts, always apply force to the inner races of the bearing.

9. Bearing Lubrication. Lubricate bearings before reassembly with the type of lubricant normally used in the related housing or container. This will provide lubrication during the first run-in until lubricant from the system can reach the bearings.

1. Preparation. Before installing any parts, make sure they are clean and that both mounting surfaces are clean and free of oil and grease (unless otherwise noted).

2. installation. Make sure there is enough clearance to install part. Disassemble adjacent parts as needed to provide working clearance.

3. Lifting. Always use chain hoist, jack, or other aid when lifting heavy parts. Make certain load limit of lifting device exceeds weight being lifted. Position and rig lifting device before connecting part for installation.

Keep light coat of lubricating oil (PL-medium or PL-special) on parts during repair procedures to prevent rusting. Lubricate parts during the repair and assembly as required by TM 9-2320-363-20, Unit PMCS.

Use the torque values listed in the maintenance procedures, if they are given. When no torque values are given in the maintenance procedures, refer to the torque value guide in Appendix D.

This chapter illustrates and describes procedures for maintenance of the power package.

Section I. Engine Assembly and Related Parts Removal and. Installation . . . . . . . . . 3-2

Section II. Transmission and Transfer Case Removal and Installation . . . . . . . . . . . 3-234