CH-34 Helicopter.

TM 55-4920-201-14

4-57. CH-34 Helicopter.

4-58. CH-34 Engine Fan Assembly Balance

Check. (See figure 4-34).

a. Assemble hoist support (2, 3, 4, 5, and 9,

figure 1-13) with no. 4 and no. 5 elbows in outer

most positions on no. 2 and no. 6 tubes so as to

provide radial clearance for engine fan assembly.

b. Center engine fan assembly (1, figure 4-

34), with shroud (if installed) upward, on stand, on

stand table assembly (1, figure 1-13).

c. Install cone (2, figure 4-34), part no. 2227

(7A050 kit), hub upward, on balancing arbor (4)

so that top of cone hub aligns with 13 inch

position (shrouded fans), 13-7 / 8-inch position

(unshrouded fans) on arbor scale (5). Lock cone

setscrew (3) with 1/8 inch hex wrench (8, figure 1-

13).

d. Insert balancing arbor (4, figure 4-34)

downward through fan hub until cone (2) contacts

upper cone seat of fan hub.

e. Install cone (6), part no. 2228 (7A050

kit), upward on bottom of balancing arbor (4),

making certain that cone seats firmly in bottom

cone seat of fan hub.

f. Install spacers (7), part no. 2202 and 2204

(7A050 kit), on balancing arbor (4) under cone (6)

hub.

g. Install hand wheel (26, figure 1-13) in

bottom end of arbor, and tighten wheel to clamp

spacers, bottom cone, fan hub, and top cone

securely together.

h. Install 3 / 16-inch suspension cable (13,

figure 1-13) and quick-disconnect coupling (10)

assembly on suspension rod at top end of arbor, and

I. Engine fan assembly

engage suspension cable in lifting plate of hydraulic

2. Cone

pump assembly.

3. Cone set screw

i. Hoist entire assembly approximately

4. Arbor (2259, 7A050 kit)

inch off work stand. Check to insure that

5. Arbor scale

suspended assembly is free from interference with

6. Cone

work stand and other objects, and note the balance

7. Spacer

condition indicated by black indicator disc at top

Figure 4-34. Typical Balancer Installation -CH-34

end of the arbor.

and CH-37 Helicopter Engine Fan Assemblies.

j. For balance tolerance and application of

balance corrections, refer to applicable helicopter

manual. (Refer to appendix A).

4-55