1 Remove the hub (23) in accordance with step (4)(c), above.
2 Slide the fan (55) off the shaft.
Main Rotor Core and Winding.
(a) Test. Test the main rotor winding in accordance with paragraph 5-6, step b.
(b) Remove. Remove main rotor assembly in accordance with step a, above.
(c) Inspect and clean.
1 Check rotor winding for signs of overheating. Check for loose, frayed, or burnt winding.
2 Clean all metal parts of rotor core with solvent PD8, Type li1, or equivalent. Remove dust and dirt
from rotor windings with a soft cloth or brush.
If a piece of wire Is used to clean the air channels, take care not to scratch the
winding or Insulation failure could occur.
3 Remove any accumulated dust or dirt in the winding air channels with a piece of wire or with low
pressure, moisture-free air.
(d) Repair. A damaged or defective rotor winding must be returned to the manufacturer for rewinding.
Assemble. See Figure 5-1. Assemble main rotor assembly (15) as follows: (1) Install Bearing Cap and Bearing.
(a) Fill bearing cap (18) grease cavity 1/3 to 112 full of new multi purpose lithium based grease, MILT-
Install new oil seal (7). Slide bearing cap onto bearing end of main rotor assembly (15).
Never install an old bearing. Always use a new bearing.
(b) Heat new bail bearing (39) in an oven to approximately 212OF (100,C).
(c) Apply a thin coat of dean lubricating oil MILT-1 8709, to the press fit area of the main rotor shaft.
Under no circumstances should pressure be applied to the outer race of the
bearing, as permanent bearing damage could result. If the ball bearing binds on
the shaft before being fully seated, then a piece of tubing, slightly larger than the
press fit area, can be used to drive the ball bearing Into place. Using light taps
with a soft mallet, apply pressure to the Inner race only.
(d) Using heat resistant gloves, install ball bearing (39), with the seal side facing the bearing cap(18), over
the end of the shaft until it seats against the shaft shoulder. The ball bearing (39) should slide onto the
shaft and be seated without excessive force.
(e) Allow ball bearing (39) to cool for 1 hour before attempting to assemble the generator.
Install fan (55, Figure 5-1).
The rotor assembly must be rebalanced if a new fan is installed.
(a) Slide the fan (55, Figure 5-1) over the drive end of the main rotor shaft making sure the fan mounting
surface is toward the hub (23).