BALANCING ARBOR PART NO. 2259.

TM 55-4920-201-14

NOTE

3-4. BALANCING ARBOR PART NO. 2259.

For temporary storage, keep arbor in

3-7. Unpacking.

upright position, as dash-pot damping oil

a. Disengage arbor retaining spring (27,

can leak out after removal of sealing tape

figure 1-13). Remove balancing arbor (23, figure 1-

and sealing gasket from under indicator

13) from 7A050 storage came, and screw hand

bushing if arbor lies on its side.

wheel (26) into bottom end of arbor. Stand arbor

3-8. Handling. The balancing arbors are precision

and hand wheel assembly safely upright on bench.

instruments and, if treated accordingly, will give

b. Using tag string, pull upper oil seal sleeve

good services indefinitely. However, to prevent

off end of arbor suspension rod.

critical damage, always observe the following

WARNING

handling precautions.

Cleaning may be toxic. Use in well-ven-

a. Particularly avoid excessive sidewire or

tilated area. Avoid prolonged inhalation

downward loading of the projecting suspension rod

of fumes or direct contact with akin. Do

end, since internal damage to the sensitive internal

not use solvent near open flame or in area

suspension element may result. For example:

where very high temperatures prevail.

dropping the inverted arbor on the suspension rod

end, from any appreciable height will result in

permanent critical damage. Similarly, any bumping

CAUTION

of the projecting suspension rod end, in any

Before removing arbor from stor-

position, shall always be avoided.

age case, read paragraph 3-8, Hand-

b. The outride diameter of the arbor is a

ling Precautions.

precision finished piloting surface. This surface

shall always be protected against accidental

c. Loosen set screw of indicator bushing (See

contacts which would cause nicks, burrs, abrasion,

figure 3-5) and lift indicator bushing from

or corrosion. Leaving the bare arbor standing on

suspension rod. Remove lower oil seal (O-ring)

end where it may be knocked over is a particularly

from suspension rod outer sleeve. Retain O-ring for

bad practice.

inactive storage or shipment (see paragraph 3-46).

c. Always handle the arbor by the knurled

Carefully clean all residual oil and preservative

section while supporting the lower end with the

compound from top surface of arbor, suspension

other hand. Make it a practice to return the arbor

rod assembly and indicator bushing, For best

to its place in the storage case when not actually in

indicator contrast, thoroughly de-grease there

we.

surfaces, using clean cloth moistened with solvent,

d. Do not disturb pressed-in plugs in eight

Federal Specification P-D-660, or equivalent

holes in lower section of arbor, and do not attempt

volatile cleaner.

removal of the arbor top cap. Arbor must be

d. Using two small pieces of paper under

returned to factory for repair if these parts are

indicator bushing as shims, re-install indicator

disturbed.

bushing and tighten set screw, (See figure 3-5.)

e. For lubrication instructions to be obrerved

a. Remove paper shims, and check to insure

prior to each application of the arbor and for in-

that indicator bushing mover freely over black

structions on adding damping oil to the arbor fluid

indicator dire (2, figure 1-27) without binding.

reservoir, refer to section V.

Change 3 3-7