TM 104320-310-14
4-14. REPLACE DIFFUSER, IMPELLER, SHAFT SEAL, BACKHEAD AND STUB SHAFT (Continued)
4
Remove four hexagon head bolts (12) and lock washers (13) and carefully pull backhead (14) from engine.
5
Remove stub shaft (7) from engine crankshaft with a puller. Be careful not to lose key (15).
CLEANING:
Dry cleaning solvent P-D-680 (safety or Stoddard's
Solvent) is potentially dangerous. Avoid repeated and
prolonged breathing of vapors and skin contact with the
liquid. Do not use near open flame, arcing equipment, or
other ignition sources. Always wear eye protection and
protective clothing. The flash point of P-D-680 is 100OF to
138OF (380C to 590C).
Death or serious injury could occur if compressed air Is
directed against the skin. Do not use compressed air for
cleaning or drying unless the pressure is/has been reduced
to 30 psi (2.06 bar) or less. When working with
compressed air always use chip guards, eye protection,
and other personal equipment.
Clean all removed parts with P-D-680 dry cleaning solvent and dry with compressed air. Use a probe to remove any
obstructions from impeller assembly (4) vanes.
INSPECTION:
1
Use a feeler gauge and inspect wear rings on mating diffuser assembly (2) and impeller assembly (4) for excessive
wear. If wear ring clearance exceeds 0.030 inch per side, 0.060 inch diameter, notify direct support maintenance.
2
Inspect mating lapped surfaces on stationary and rotary elements of shaft seal (10) for uneven wear, grooves burning
or other similar damage. If any of these conditions exist, or if flammable fluid leakage was noted at the rear of the
backhead, replace the shaft seal.
3
Inspect all other parts for excessive wear, rust, corrosion or other damage. Replace any other worn or damaged
parts.
INSTALLATION:
1
Press stub shaft (7) fully onto crankshaft being sure key (15) is in place.
2
Carefully install backhead (14) over stub shaft (7) and secure to engine with four hexagon head bolts (12) and new
lock washers (13). Torque hexagon head bolts evenly in an alternating pattern to 40 inch-pounds.
3
Apply silicone to new preformed packing (11). Install preformed packing (11) onto backhead (14).
4
Apply silicone to shaft seal assembly (10). Carefully and in the proper orientation, press shaft seal assembly parts
over stub shaft and fully into backhead (14) recess.
4-15
