Pontiac TRANS AM 1977 Service Manual page 243

3-1 4
1977 PONTIAC SERVICE MANUAL
WHEEL BEARING DIAGNOSIS (CONT'D)
RACE CRACKFD OUE TO IMPROPER F1T
COCKING OR POOR BEARING SEATS
REPLACE BEARING AND CORRECT BEARlNG
SEAT S
FRETTAGE
CORROSION SET UP BY SMALL RELATIVE
MOVEMENT OF PARTS WlTH N O LUBRICATION
REPLACE BEARING CLFAN RELATEDPARTS
CHECK SEALS AND CHECK FOR PROPER LUBRICATION
SMEARS
SMEARING OF METAL DUE TO SLIPPAGE
SLIPPAGE CAN BE CAUSED BY POOR f ITS
LUBRICATION. OVERHEATING. OVERLOADS
OR HANDLING DAMAGE
REPLACE BEARINGS CLEAN RELATED PAFlTS
A A O W E C K FOR PROPER F I T S A N D
LUBRICATION
FATIGUE S P A L L I N G
F L A K I N G O F SURFACE METAL R E S U L T I M FROM
FATIGUE
REPLACE BEARING CLEAN A L L RELATED PARTS
-- - -
STAIN DISCOLORATION
DISCOLORATION CAN RANGE FROM LIGHT BROWh
TO BLACS CAUSED BY INCORRECT LUBRICANT OR
MOISTURE
RE USE BEARINGS I F STAILIS CAN BE REMOVED BY
LIGHT POLISHING OR I F
NO
EVIDENCE O f OVER
HEATING IS OBSERVED
CHECK SEALS AND RELATED PARTS FOR DAMAGE
BRINELLING
SURFACE INDENTATIONS I N RACEWAY CAUSED BY
ROLLERS EITHER UNDER IMPACT I.OfiD1NG OR
VIERATION WHILE THE BEAHlkG ISNOT R O T A l l N G
REPLACE BEARING I F ROUGH OR NOISY
HEAT DISCOLORATION
HEAT DISCOLORATICW CAN RANGE FROM FAINT
YELLOICTOOARKBLUE RESULTINGFROHOVER
LOAD OR INCORRECT LUBRICANT
EXCESSIVE HEAT CAN CAUSE SOFTENING OF RACES
OR ROLLERS
TO CHECK FOR LOSS O F TEMPER O N RACES OR
ROLLERS 4 StMPLE FlLE TEST M A Y BE MADE A
FlLE ORAWN OVER A TFMPERFDPART WlLL GRAB
ANDCUT METAL. WHEF4EAS.A FlLE DRAWNOVER A
HARD PART WlLL GLIDE READILY WlTH NO METAL
CUTTING
REPLACE BEARINGS I F OVER HEATING DAMAGE IS
INDICATED CHECK SEALS AND OTHER PARTS
Fig. 3-1 1 Front Wheel Bearing Diagnosis