Reassembly - TM-10-3930-644-14-P0259

TM 10-3930-644-14 & P

To install a new bearing, press in with a tube or

hollow cylinder to prevent breakage of the end

collar that just fits over the outer race, with the

frame. Use extreme care to avoid misalignment

bearing and slinger assembled into the end

or otherwise plating undue stress on the

frame as shown in Figure 2-12.

It is

bearing.

recommended that a new retainer plate be

installed if the felt seal in the retainer plate is

If the seal is separate from the bearing, it is

hardened or excessively worn. Fill the cavity

recommended that a new seal be installed

between the retainer plate and bearing with

whenever the bearing is replaced. Press the

1948791 lubricant.

seal : n with the lip of the seal toward the rotor

when assembled, that is, away from the bearing.

Lightly coat the seal lip with oil to facilitate

assembly of the shaft into-the bearing.

9. Reassembly

Assembling the pulley assembly, remembering

to secure the rotor in a vise only tight enough to

permit tightening the shaft nut to 40-60 lb. ft. If

excessive pressure is applied against the rotor,

the assembly may become distorted. To install

the slip ring end frame assembly to the rotor and

drive end frame assembly, remove the tape over

the bearing and shaft, and make sure the shaft

is perfectly clean after removing the tape. Insert

a pin through the holes to hold up the brushes.

Carefully install the shaft into the slip ring end

frame assembly to avoid damage to the seal.

Figure 2-12. Drive End Bearing Assembly

After tightening the thru-bolts remove the brush

(Some models use flat washer

retaining pin to allow the brushes to fall down

instead of slinger)

into the slip rings.

The bearing in the slip ring end frame should be

10. Alternator Bench Check

replaced if its grease supply is exhausted. No

attempt should be made to re-lubricate and

To check the alternator in a test stand, proceed

reuse the bearing. To remove the bearing from

as follows:

the slip ring end frame, press out with a tube or

collar that just fits inside the end frame housing.

a. Make connections as shown in Figure 2-

Press from the outside of the housing towards

14, except leave the carbon pile

the inside.

disconnected.

IMPORTANT:

Ground

polarity of battery and alternator must be

To install a new bearing, place a flat plate over

the same. Use a fully charged battery,

the bearing and press in from the outside

and 10 ohm resistor rated at 6 watts or

towards the inside of the frame until the bearing

more between the alternator No. 1

is flush with the outside of the end frame.

terminal and the battery.

Support the inside of the frame with a

b. Slowly increase the alternator speed and

observe the voltage.

R-146-1

3-89