Section V. Periodic Inspection, Maintenance, and Lubrication

TM 55-4920-201-14

SECTION

PERIODIC

INSPECTION,

MAINTENANCE,

AND

LUBRICATION

5-1. INSPECTION.

(2262) and the quick-disconnect coupling (2266).

Install and secure the rear cone (2228), collar up,

5-2. General. Inspection of the equipment

at the extreme top end of the suspended arbor.

described in this manual at regularly scheduled

Stabilize the suspended assembly. Eliminate its

intervals is not required. However, the following

tendency to revolve or swing. Free the suspended

inspections should be performed each time the

assembly from any obstruction or interference.

equipment is removed from storage and prepared

After the suspended assembly has stabilized, note

for use.

the indicator bushing position in relation to the

5-3. Balance Arbors. Visually examine all

black indicator disc. An arbor that indicates

surfaces of the arbor for detrimental physical

balance eccentricity to the point of tangency

damage such as burrs, nicks, dents, scratches or

illustrated in view C, figure 1-28, is acceptable end

corrosion. If any arbor is reportedly discrepant

completely serviceable. However, overlapping

and/ or is suspected of having been damaged

circles are an indication that the arbor is out-of-

wherein the internal suspension element has been

balance beyond acceptable limits (providing in-

bent or deformed, a serviceability check of the

dicator bushing interference, dash-pot oil, and

arbor shall be accomplished. First, inspect for

cable discrepancy possibilities have been

possible binding of the indicator bushing and

eliminated). See view D, figure 1-28.

correct for this condition, if necessary. Appropriate

indicator bushing instructions are provided in

NOTE

paragraph 3-7. Check the oil in the arbor to make

Cables shall be straight, without kinks or

sure it is clean, fluid, and authorized. Drain un-

twists. Suspension cables incorporating a

satisfactory oil; clean and refill arbor, if required,

swaged shank junction at the coupling end

as described in paragraph 5-21. If an arbor has

may introduce errors due to a bent swaged

been stored on its side (horizontally) for a con-

connection. To check if a cable is

siderable length of time, particularly at low tem-

satisfactory revolve it 180O and observe

perature, eccentric balance indications may be due

whether the unbalance indicated, if present,

to improper distribution and / or congealing of the

approximately follows the rotated cable

dash-pot oil. This condition shall be corrected by

or remains in a constant location. If the

suspending the arbor at room temperature until the

unbalance indication follows the rotated

oil becomes fluid and uniformly distributed. If it is

position of the cable, the cable is damaged

necessary to verify the correct alignment and

or the swaged section is bent. The cable

condition of the arbor's internal suspension

shell be replaced or repaired satisfactorily

element, adhere to the following instructions.

before proceeding with the balance check

of the arbor.

CAUTION

Do not attempt to disassemble or repair

b. Part no. 2516 arbor. First check the

balancing arbors. Except for ad-

suspected arbor for possible indicator bushing

justment of indicator bushings (refer to

binding or dash-pot oil discrepancies as described

paragraph 3-7) and removal of oil filler

in paragraph 5-3 above. If necessary, check the

screws (refer to paragraph 5-21), these

alignment of the internal suspension element by

arbors are permanent assemblies, and

adhering to the following instructions. Suspend the

any disassembly by using activities will

cleaned, bare arbor to be checked using the eye

result in critical damage requiring

assembly (23871, or a suspension cable (2262 or

factory repair. Refer to section VI,

2264), in combination with the quick-disconnect

troubleshooting, for correction of

coupling (2266), available in the 7A050 kit. Install

abnormal symptons, permitted by field

the counterweight (2523), small collar up, on the

activities during the balance check of

arbor so that the top of the counterweight collar is

balance arbor assemblies.

in line with the 9 inch scale mark on the arbor.

Tighten the set screw to retain the counterweight on

a. Part no. 2259 arbor. Suspend cleaned,

the arbor. Because of the design of the 2516 arbor

bare arbor to be checked using the 1 / 16" cable

5-1