GMC 1976 ZEO 6083 Maintenance Manual page 541

STEERING 9- 9
STEERING GEAR AND PUMP DIAGNOSIS CHART (Cont'd.)
Condition
Possible Cause
Correction
Growl noise in steering
1 . Excessive back pressure
I . Locate restriction and correct.
,pump.
in hoses or steering gear
Replace part if necessary.
caused by restriction .
Growl noise in steering
1 . Scored pressure plates,
1 . Replace parts and flush system .
pump . (Particularly
thrust plate or rotor.
noticeable at stand
still parking) .
2 . Extreme wear of cam
2. Replace parts.
ring .
Groan noise in steering
1 . Low oil level.
1 . Fill reservoir to proper level.
pump .
2. Air in the oil. Poor
2 . Tighten connector to specified
pressure hose connection .
torque . Bleed system by operating
steering from right to left-full
turn .
Rattle or knock noise
1 . Loose pump pulley nut.
1 . Tighten nut to specified torque .
in steering pump .
Rattle noise in steering
1 . Vanes not installed
1 . Install properly .
pump .
properly .
2 . Vanes sticking in rotor
2 . Free up by removing burrs,
slots.
varnish or dirt .
Swish noise in steering
1 . Defective flow control
1. Replace part.
pump .
valve.
Whine noise in steering
1 . Pump shaft bearing
1 . Replace housing and shaft . Flush
pump .
scored .
system .
Poor return of steering
1 . Lack of lubrication in
1 . Lube linkage and ball joints .
wheel to center .
linkage and ball joints .
2 . Lower coupling flange
2. Loosen pinch bolt and assemble
rubbing against steering
properly .
gear adjuster plug .
3. Steering gear to column
3 . Align steering column .
_ misalignment .
4. Tires not properly
4. Inflate to specified pressure .
inflated .
5. Improper front wheel
5. Check and adjust as necessary.
alignment.
With front wheels still on alignment
pads of front end machine, discon-
nect pitman arm of linkage from
pitman shaft of gear . Turn front
wheels by hand . If wheels will not
turn or are difficult to turn,
determine if linkage or ball
joints are binding.