GMC 1976 ZEO 6083 Maintenance Manual page 540

9- 8
STEERING
STEERING GEAR AND PUMP DIAGNOSIS CHART
Condition Possible Cause Correction
Hissing noise in 1 . There is some noise in 1 . Slight "hiss" is normal and in
steering gear . all power steering sys- no way affects steering . Do not
tems . One of the most replace valve unless "hiss" is ex-
common is a hissing tremely objectionable. A replacement
sound most evident at valve will also exhibit slight noise
standstill parking. There and is not always a cure for the ob-
is no relationship be- jection. Investigate clearance
tween this noise and per-
around flexible coupling rivets . Be
formance of the steering . sure steering shaft and gear are
"Hiss" may be expected aligned so flexible coupling rotates
when steering wheel is at
in a flat plane and is not distorted
end of travel or when
as shaft rotates. Any metal-to-metal
slowly turning at contacts through flexible coupling
standstill . will transmit valve "hiss" into
passenger compartment through the
steering column .
Rattle or chuckle noise 1 . Gear loose on frame. 1 . Check gear-to-frame mounting
in steering gear . screws . Tighten screws to 70-foot-
pounds .
2. Steering linkage loose- 2. Check linkage pivot points for
ness .
wear . Replace if necessary.
3. Pressure hose touching 3 . Adjust hose position . Do not
other parts of vehicle. bend tubing by hand .
4. Loose pitman shaft
4. Adjust to specifications .
over center adjustment
NOTE : A slight rattle may
occur on turns because of
increased clearance off
the "high point." . This is
normal and clearance must
not be reduced below
specified limits to
eliminate this slight
rattle .
5 . Loose pitman arm. 5. Tighten pitman arm nut to
specifications .
Squawk noise in steering 1 . Damper "O" ring on
1 . Replace damper "O" ring .
gear when turning or valve spool cut .
recovering from a turn . 2 . Improper fluid in 2. Flush and refill using power
system .
steering fluid (GM 105007).
Chirp noise in steering 1 . Loose belt . 1 . Adjust belt tension to
pump . specification .
Belt squeal
1. Loose belt . 1 . Adjust belt tension to
(Particularly noticeable
specification .
at full wheel travel
and stand still
parking) .