Chevrolet 1977 light duty truck Service Manual page 382

FRONT W HEEL BEA RIN G D IA G N O S IS
C R A C K E D I N N E R RACE
RACE CRAC K ED DUE TO IMPROPER F IT ,
C OCKING. OR POOR B E A RING SEATS.
REPLACE BEAR IN G A N D CORRECT BEARING
SEATS.
FRETTAGE
CORROSION SET UP BY SM ALL R E L A T IV E
M O V E M EN T OF PARTS W ITH NO LU B R IC A TIO N .
REPLACE B E A R ING . C L E A N R EL A T E D PARTS.
CHECK SEALS AN D CHECK FOR PROPER LU B R IC A TIO N .
SMEARS
SM EARING OF M E T A L DUE TO SLIPPAGE.
SLIPPAGE CA N BE C A U SED BY POOR FITS.
L U B R IC A T IO N , O V E R H E A T IN G , O VER LO A D S
OR H A N D L IN G D A M A G E.
REPLACE B EA R IN GS, CLE A N R E L A T E D PARTS
AND CHECK FOR PROPER FITS AND
LUB R IC A TIO N
F AT I GUE S P A L L I N G
F L A K IN G OF SURFACE M E TA L R ESU LTIN G FROM
FA TIG U E .
REPLACE B EA R IN G C LE A N ALL R E L A T E D PARTS.
mm
ST AI N D I SC O L O R A T I O N
D ISC O LO R A TIO N CAN RANGE FROM L IG H T BROWN
TO BLACK CAUSED BY IN CORRECT LU B R IC A N T OR
MOISTURE.
RE USE B EAR IN G S IF STA IN S CAN BE R EM O VED BY
LIG H T PO LISH IN G OR IF NO EVIDENCE OF OVER
H E A TIN G IS OBSERVED.
CHECK SEALS A ND R E L A T E D PARTS FOR DAM AGE.
(C O N T'D)
Hll A
BRI NELLI NG
SURFACE IN D E N TA T IO N S IN RACEW AY CAUSED BY
ROLLERS EITH ER UNDER IM PACT LO A D IN G OR
V IB R A T IO N W HILE THE B EARING IS NOT R O TA TIN G .
REPLACE BEARING IF ROUGH OR NOISY.
HUM
m a tk \
Iflllfi
HEAT D I SCO L ORAT I O N
HEAT D ISCO LO RATIO N CAN RANGE FROM FA IN T
YELLO W TO DAR K BLUE R ESU LTING FROM OVER
LOAD (WAGON'S) OR IN CORR ECT LUBR ICANT.
EXCESSIVE HEAT CAN CAUSE SO FTENING OF RACES
OR ROLLERS.
TO CHECK FOR LOSS OF TEMPER ON RACES OR
ROLLERS A SIMPLE FILE TEST M A Y BE M ADE. A
FILE DRAWN OVER A TEM PERED PART W ILL GRAB
AMn P IIT U C T A I lAfUCDC AC A C II C HQ AUUM rt\/C D A
AIMU i_U 1 IVtt 1 A L, W M tn tA o , A M L t UrlAWIM U V t n A
H A R D PART W IL L G LID E R E A D IL Y W ITH NO M ETAL
C U TTIN G .
REPLACE BEAR INGS IF O VER H E A TIN G DAMAGE IS
IN D IC A T E D . CHECK SEALS A N D OTHER PARTS.