Chevrolet Light Duty Truck 1973, Service Manual

Page: 264 / 979

4 - 4 0 REAR S U S PEN SIO N AND DRIVELINE
DIFFERENTIAL A N D REAR AXLE B EA RING D IA G N O S IS
(C O N T ’D)
C R A C K E D I N N E R RACE
RACE CRACKED DUE TO IMPROPER FIT,
COCKING, OR POOR BEARING SEATS.
REPLACE BEARING A N D CORRECT BEARING
SEATS.
FRET TA GE
CORROSION SET UP BY S M A LL R E L A T IV E
MOVEM ENT OF PARTS WITH NO L U B R IC AT IO N .
REPLACE B EARING . C LEAN R E LATE D PARTS.
CHECK SEALS AND CHECK FOR PROPER L U B R IC AT IO N .
SMEARS
SMEARING OF M E TA L DUE TO SLIPPAGE.
SLIPPAGE CAN BE CAUSED BY POOR FITS.
LU B R IC A T IO N , OVE R H EA TIN G , OVERLO AD S
OR H A N D L IN G DAMAGE.
REPLACE BEARINGS, CLEAN R E LATE D PARTS
AND CHECK FOR PROPER FITS AND
LU B R IC AT IO N
B R IN E LL IN G
SURFACE IN D E N TA TIO N S IN RACEWAY CAUSED BY
ROLLERS EITHER UNDER IMPACT LOA DING OR
V IB R A T IO N W HILE THE BEA RING IS NOT R O TATING .
REPLACE BEARING IF ROUGH OR NOISY.
FATIGUE SPALLING
FLA K IN G OF SURFACE M E TA L RESULTING FROM
FATIGU E.
REPLACE BEARING CLE AN A L L R E LATE D PARTS.
DIS COLORATION CAN RANGE FROM LIG H T BROWN
TO BLACK CAUSED BY INCORRECT L U B R IC AN T OR
MOISTURE.
RE-USE BEARINGS IF STAINS CAN BE REMOVED BY
LIG H T POLISHING OR IF NO EVIDENCE OF O V E R ­
HEATIN G IS OBSERVED.
CHECK SEALS A N D RE LATE D PARTS FOR DAM AGE.
HEAT D I S C O L O R A T IO N
HEAT DISCO LO RATIO N CAN RANGE FROM FA IN T
YELLOW TO D A R K BLUE RESULTING FROM OVER
LOAD (WAGON'S) OR INCORRECT LUB RICAN T.
EXCESSIVE HEAT CAN CAUSE SOFTENING OF RACES
OR ROLLERS.
TO CHECK FOR LOSS OF TEMPER ON RACES OR
ROLLERS A SIMPLE FILE TEST M A Y BE MADE. A
FILE DRAWN OVER A TEMPERED PART W IL L GRAB
AND CUT M E T A L, WHEREAS, A FILE DRAWN OVER A
HARD PART W IL L G LID E R E A D ILY WITH NO M E TA L
CUTTING.
REPLACE BEARING S IF OVER H EATIN G DAMAGE IS
IN D IC A TE D . CHECK SEALS A N D OTHER PARTS.
S T AIN D I S C O L O R A T IO N
Fig. 82—Differential and Axle Bearing Diagnosis Chart B
LIGHT DUTY TRUCK SERVICE MANUAL