Section III. GENERAL MAINTENANCE

TM 9-2520-246-34

Section III. GENERAL MAINTENANCE

cleaning equipment, or by hand brushing, using

2-7. General. Because the transmissions, transfers,

drycleaning solvent, type II (SD-2), Fed Spec P-D-

and power takeoffs are very similar in construction

680, as a cleaning agent. Total immersion in a dip

and material, use generalized cleaning practices, as

tank is also approved, provided the cleaning agent is

recommended. If and when special cleaning practices

drycleaning solvent. The use of stronger cleaning

are required, refer to the specific cleaning instructions

agents, such as caustic soda or detergents, is

in the pertinent chapter.

prohibited because of the corrosive effect on bearings.

2-8. Cleaning.

d. Cleaning Component Parts After Disassembly.

a. Cleanliness. Cleanliness of personnel, tools, and

(1) It is essential that the equipment used during

area surroundings is not only good practice, but it is a

the cleaning operation suit the particular cleaning job

fundamental requirement when mechanical repairs are

being performed. Round brushes should be used for

performed. This is particularly true of the areas in

internal bores, and square or rectangular brushes

which transmissions, transfers, and power takeoffs are

should be used for flat or external surfaces. Each part

repaired or rebuilt. All of the information and

should be cleaned thoroughly and individually.

instructions contained in this manual are given with

the assumption that these conditions prevail in the

NOTE

working area. Transmission, transfer, and power

takeoff repairs, except those of an emergency nature,

Bearings require special handling. Cleaning,

should never be accomplished under any other

inspection, and preparation for use of ball

conditions.

and roller bearings are covered in TM 9-

214.

b. Precautions.

(2) Clean all other parts of hardened oil, lacquer

(1) Do not use drycleaning solvent, type II, (SD-2)

deposits, and dirt, paying particular attention to the

Fed Spec P-D-680, near an open flame because it is

small oil holes in the gears and to the lock ball bores

flammable. Fire extinguishers must be provided when

in the shifter shaft cover. Remove all gaskets or parts

this material is used. Avoid contact of these solvents with

of gaskets from surfaces, using a putty knife or other

the skin as they may cause cracks, mild irritation or

suitable scraper. Be careful to avoid scratching or

inflammation of the skin.

gouging the surface metal.

(2) Avoid contact of drycleaning solvent or

(3) Rinse the parts in clean drycleaning solvent

lubricants with rubber parts since these materials can

type II (SD-2), Fed Spec P-D-680. This is a highly

cause deterioration.

important operation. Spraying solvent over the parts

or suspending the part in a mechanically agitated bath

(3) The use of gasoline, mineral spirits paint

of solvent are the preferred methods of rinsing. In the

thinner, or benzine for cleaning is strictly prohibited.

absence of such facilities, however, the parts may be

rinsed by immersing them in a container of clean

c. Cleaning Transmission, Transfer, and Power

drycleaning solvent and shaking them vigorously. Dry

Takeoff Assemblies Prior to Disassembly.

the parts with compressed air.

(1) Scrape or brush all accumulations of dirt or

2-9. Inspection.

road mud from the transmission case and attached

parts with a scraper or wire brush. Note and mark, by

a. General.

scratching the case with a sharp-pointed tool, any

moist oil spots or unusually heavy accumulations of

(1) This section contains general inspection

oil-soaked road mud, for these are good clues to the

procedures for transmissions, transfers, and power

location of small cracks or holes that might escape

takeoffs. Not all inspection procedures will apply to

notice in a visual inspection. However, do not confuse

each assembly. Therefore, it will be up to maintenance

these accumulations with those that result from

leaking gaskets or oil seals. A leak at a seal or a

personnel to apply the pertinent procedure to the

gasket is more or less normal for an assembly that has

assembly which they are inspecting. Most inspection

been in service for any length of time, and the area

procedures will apply to all assemblies. Special

inspection procedures for an assembly are given in the

covered is generally localized around the shaft bores,

respective chapter for that assembly.

power takeoff openings, etc.

(2) All parts must be thoroughly examined and

(2) Complete external cleaning with steam-

2-15