Piper Navajo PA-31 Service Manual page 707

PIPER NAVAJO SERVICE MANUAL
CAUTION
Do not strike
the diode, as the shock may damage the
other diodes.
11-14. SLIP RING SERVICING.
If the slip rings are dirty, they may be cleaned
and finished with 400-grain
or finer polishing cloth. Spin the rotor in a lathe,
or otherwise spin the rotor,
and hold the polishing cloth against
the slip rings
until they are clean.
CAUTION
The rotor must be rotated in order that the slip rings
will be cleaned evenly.
Cleaning the slip rings byhand
without spinning
the rotor may result in flat spots on
the slip rings, causing brush noise.
Slip rings
which are rough or out of round should be trued in a lathe to
002-inch maximum
indicator reading. Remove only enough material
to make
the rings smooth
and round. Finish with 400-grain
or finer polishing cloth and
blow away all dust.
11-15. BEARING REPLACEMENT
AND LUBRICATION. The bearingin
the drive
end frame can be removed by detaching the retainer
plate screws,
and then press -
ing the bearing from the end frame.
If the bearing is in satisfactory
condition,
it may be reused, and it should be filled one quarter full with DELCO-REMY lubricant No.
1960373 before reassembly.
CAUTION
Do not overfill,
as this may cause the bearing to over-
heat, and use only 1960373 lubricant.
To install a new bearing,
press in with a tube or collar
that just fits over
the outer race. It is recommended that a new retainer
plate be installed
if the
felt seal in the retainer plate is hardened or excessively
worn.
The bearing in the slip ring end frame should be replaced
if its grease sup-
ply is exhausted. No attempt
should be made to re-lubricate
and re-use the
bearing.
To remove the bearing from the slip ring end frame,
press out with a
tube or collar that just fits inside the end frame housing.
Press from the outside
Reissued: 10/12/79
ELECTRICAL
SYSTEM
Effectivity
DELCO
4B5