CLUTCH AND TRANSMISSIONS 7-40
pipes.
If
care
is
taken
in
removing control valve
body
the six (6)
check balls will stay
in
place above
the spacer plate.
CAUTION:
Do not
drop manual valve.
5. Remove
the
governor pipes
and
manual valve from
control valve body.
Installation
Installation
of the
control valve body
is the
reverse
of
the removal.
GOVERNOR
Removal
.
1.
Remove governor cover attaching screws, cover,
and
gasket.
2.
Discard gasket.
3.
Withdraw governor assembly from case.
Installation
Installation
of the
governor assembly
is the
reverse
of
the removal.
Use a new
gasket under
the
governor
cover.
MODULATOR AND MODULATOR VALVE
Removal
1.
Remove modulator assembly attaching screw
and
retainer.
2.
Remove modulator assembly from case. Discard
"O"
ring seal.
3.
Remove modulator valve from case.
Installation
Installation
of the
modulator assembly
and
modulator
valve
is the
reverse
of the
removal.
Use a new
"O" ring
seal
on the
modulator assembly.
PARKING LINKAGE
Removal
1.
Remove bottom
pan and oil
strainer.
2.
Unthread
jam nut
holding detent lever
to
manual
shaft.
3.
Remove manual shaft retaining
pin
from case.
4.
Remove manual shaft
and jam nut
from case.
NOTE:
DO NOT
remove manual shaft seal
un-
less replacement
is
required.
5. Remove parking actuator
rod and
detent lever
as-
sembly.
6. Remove parking pawl bracket attaching screws
and
bracket.
7. Remove parking pawl return spring.
NOTE:
The
following steps should
not be com-
pleted unless part replacement
is
required.
8. Remove parking pawl shaft retainer.
9.
Remove parking pawl shaft,
cup
plug, parking pawl
shaft, and parking pawl.
Installation
Installation
of the
parking linkage
is the
reverse
of the
removal.
Use new
seal
and cup
plug,
if
removed,
and
new bottom
pan
gasket.
REAR SEAL
Removal
1.
Remove propeller shaft.
2.
Pry
seal
out
with screw driver.
Installation
1.
Using Tool J-5154
or
J-21359 install
new
seal.
2.
Re-install propeller shaft.
OTHER SERVICE WITH TRANSMISSION IN VEHICLE
The following operations when done
as
single opera-
tions
and not as
part
of a
general overhaul should,
as a
practical matter,
be
performed with
the
transmission
in
the.
vehicle. Refer
to the
"Transmission Disassembly
and Reassembly" section
of the
Overhaul Manual
for
service procedures.
a. Oil
filler pipe
and
"O"
ring seal.
b.
Oil pan
and
gasket.
c. Down shift solenoid
or
connector.
d. Valve body spacer plate, gasket
and
check balls.
e. Front accumulator piston.
f.
Rear servo
and
rear accumulator assembly.
g.
Rear band apply checking with Tool J-21370.
Ji.
Front servo assembly.
i. Speedo driven gear.
j.
Case extension
or
gasket.
k.
Strainer
and
"O"
ring.
TRANSMISSION REPLACEMENT
Before raising
the car,
disconnect
the
battery
and re-
lease
the
parking brake.
1.
Remove propeller shaft.
8.
2.
Disconnect speedometer cable, electrical lead to case
9.
connector, vacuum line
at
modulator,
and oil
cooler
10.
pipes.
3.
Disconnect shift control linkage.
4.
Support transmission with suitable transmission jack.
11.
5. Disconnect rear mount from frame crossmember.
6. Remove
two
bolts
at
each
end of
frame crossmember
12.
and remove crossmember.
7. Remove
oil
cooler lines, vacuum modulator line,
speedo cable,
and
detent solenoid connector wire
at
transmission.
Remove converter under
pan.
Remove converter
to
flywheel bolts.
Loosen exhaust pipe
to
manifold bolts approximately
1/4
inch,
and
lower transmission until jack
is
barely
supporting
it.
Remove transmission
to
engine mounting bolts
and
remove
oil
filler tube
at
transmission.
Raise transmission
to its
normal position, support
engine with jack
and
slide transmission rearward
from engine
and
lower
it
away from vehicle.
CHEVROLET CHASSIS SERVICE MANUAL
CLUTCH AND TRANSMISSIONS 7-41
CAUTION: Use converter holding ToolJ-5384
when lowering transmission or keep rear of
transmission lower than front so as not to lose
converter.
The installation of the transmission is the reverse of
the removal.
TURBO HYDRA-MATIC DIAGNOSIS PROCEDURE
Accurate diagnosis of transmission problems begins
with a thorough understanding of normal transmission
operation. In particular, knowing which units are in-
volved in the various speeds or shifts so that the specific
units or circuits involved in the problem can be isolated
and investigated further. Analytical diagnosis will pro-
tect the technician from come backs and certainly will
improve owner satisfaction.
An important and often overlooked aspect of diagnosis
is finding out specifically what the customer is com-
plaining of. For this purpose a short ride with the cus-
tomer will often prove beneficial. It may be found that
the condition the customer wants corrected is standard
and should not be altered.
The following sequence, based on field experience, pro-
vides the desired information quickly and in most cases
actually corrects the malfunction without requiring the
removal of the transmission. Details of the items listed
in this sequence are covered further in the text.
SEQUENCE FOR TURBO HYDRA-MATIC
DIAGNOSIS PROCEDURE
1.
Check oil level and condition.
2.
Check and correct detent switch.
3.
Check and correct vacuum line and fittings.
4.
Check and correct manual linkage.
OIL LEVEL AND CONDITION CHECK
Always check the oil level before road testing. Oil
must be visible on dip stick prior to operating the ve-
hicle. Erratic shifting, pump noise, or other malfunc-
tions can in some cases be traced to improper oil level.
Oil level should be checked with the selector lever in
the Park (P) position, engine running, and the vehicle on
level pavement.
Fluid level should be to the FULL mark with the trans-
mission at normal operating temperature (170°-190°
F.).
With warm fluid (room temperature), the level should be
at or slightly below the ADD mark.
If oil level was low, refer to Oil Leaks.
The condition of the oil is often an indication of whether
the transmission should be removed from the vehicle, or
to make further tests. When checking oil level, a burned
smell and discoloration indicate burned clutches or bands
and the transmission will have to be removed.
MANUAL LINKAGE
Manual linkage adjustment and the associated neutral
safety switch are important from a safety standpoint
The neutral safety switch should be adjusted so that the
engine will start in the Park and Neutral positions only.
With the selector lever in the Park position, the park-
ing pawl should freely engage and prevent the vehicle
from rolling. The pointer on the indicator quadrant
should line up properly with the range indicators in all
ranges.
OIL LEAKS
Before attempting to correct an oil leak, the actual
source of the leak must be determined. In many cases,
the source of the leak can be deceiving due to "wind flow"
around the engine and transmission.
The suspected area should be wiped clean of all oil be-
fore inspecting for the source of the leak. Red dye is
used in the transmission oil at the assembly plant and
will indicate if the oil leak is from the transmission.
. The use of a "black light"* to identify the oil at the
source of leak is also helpful. Comparing the oil from
the leak to that on the engine or transmission dip stick
(when viewed by black light) will determine the source
of the leak.
Oil leaks around the engine and transmission are gen-
erally carried toward the rear of the car by the air
stream. For example, a transmission "oil filler tube to
case leak" will sometimes appear as a leak at the rear of
the transmission. In determining the source of an oil
leak it is most helpful to keep the engine running.
POSSIBLE POINTS OF OIL LEAKS
• 1. TRANSMISSION OIL PAN LEAK
a. Attaching bolts not correctly torqued.
b.
Improperly installed or damaged pan gasket.
c. Oil pan gasket mounting face not flat.
2.
REAR EXTENSION LEAK
a. Attaching bolts not correctly torqued.
b.
Rear seal assembly — damaged or improperly
installed.
c. Gasket seal — (extension to case) damaged or
improperly installed.
d. Porous casting.
3.
CASE LEAK
a. Filler pipe "O" ring seal damaged or missing;
misposition of filler pipe bracket to engine —
"loading" one side of
"O"
ring.
b.
Modulator assembly "O" ring seal
—
damaged or
improperly installed.
c. Governor cover, gasket and bolts — damaged,
loose; case face leak.
d. Speedo gear
—
"O" ring damaged.
e. Manual shaft seal — damaged, improperly in-
stalled.
f. line pressure tap plug — stripped, shy sealer
compound.
g. Parking pawl shaft cup plug
—
damaged, improp-
erly installed.
h. Vent pipe (refer to Item 5).
i. Porous case.
4.
FRONT END LEAK
a. Front seal - damaged (check converter neck for
nicks,
etc., also for pump bushing moved for-
ward);
garter spring missing from pump to con-
verter seaL
b.
Pump attaching bolts and seals
—
damaged, miss-
ing, bolts loose.
CHEVROLET a
SERVICE
CLUTCH AND TRANSMISSIONS 7-42
c. Converter
—•
leak in weld.
d. Pump tfO" ring seal — damaged. (Also check
pump groove and case bore.)
e. Porous casting (pump or case).
5. OIL COMES OUT VENT PIPE
a. Transmission over-filled.
b.
Water in oil.
c. Pump to case gasket mispositioned.
d. Foreign material between pump and case, or be-
tween pump cover and body.
e. Case — porous, pump face improperly machined.
f. Pump — shy of stock on mounting faces, porous
casting.
CASE POROSITY-REPAIR
Transmission leaks caused by aluminum case porosity
have been successfully repaired with the transmission in
the vehicle by using the following procedure.
1.
Road test and bring the transmission to operating
temperature.
2.
Raise the car and, with the engine running, locate the
source of the oil leak. Check for leaks in all operat-
ing positions.
NOTE:
The use of a mirror will be helpful in
finding leaks.
3.
Shut off engine and thoroughly clean area with a sol-
vent and air dry.
4.
Using the instruction of the manufacturer, mix a suf-
ficient amount of epoxy cement, part #1360016, to
make the repair.
5. While the transmission is still hot, apply the epoxy
to the area, making certain that the area is fully
covered.
6. Allow epoxy cement to dry for three hours and re-
test for leaks, as outlined in Steps 1 and 2.
OIL PRESSURE CHECK
With Car Stationary
Transmission oil pressure gauge and engine tachome-
ter should be connected and the oil pressures should
check as follows:
1.
Pressures indicated below are at 0 output speed with
the vacuum modulator tube disconnected and with en-
gine at 1200 rpm.
Approximate
Altitude of Check
(Ft. above sea level)
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
Drive
Neutral
Park
150
150
145
138
132
126
121
116
LI
or
L2
150
150
150
150'
150
150
150
150
Reverse
244
233
222
212
203
194
186
178
2.
Pressures indicated below are with the vacuum tube
connected for normal modulator operation, and with
the engine at 1200 rpm.
NOTE:
Pressures are not significantly affected
by altitude or barometric pressure when the
vacuum tube is connected.
Drive, Neutral, Park Ll or L2 Reverse
70 150 107
TURBO HYDRA-MATIC SHIFT POINTS
Engine
Throttle
Position
Closed
Detent
Touch
Thru
Detent
V327 (L30)
2.73 Axle - 8.25 - 14 Tire
•1-2 Up
7.7-11.5
36.4-50.1
2-1 Dn
10.9-6.9
74.8-91.4
2-3 Up
17.5-22.6
85.1-67.6
3-2 Dn
19.5-14.6
43.3-26.6
Chevrolet Models
(MPH)
V396 (L35)
2.73 Axle - 8.25 - 14 Tire
1-2 Up
8.0-12.9
38.4-55.9
2-1 Dn
10.3-4.3
45.6-25.2
2-3 Up
17.2-27.8
/
74.8-91.7
3-2 Dn
18.3-12.6
83.7-65.0
V427 (L36)
2.73 Axle - 8.25 - 14 Tire
1-2 Up
8.6-12,6
44.1-58.5
2-1 Dn
1-1.7-6.6
45.8-27.2
2-3 Up
17.5-30.7
81.1-99.4
3-2 Dn
18.9-14.3
92.6-73.4
Chevelle Models (MPH)
Throttle
Position
Closed
Detent
Touch
Thru
Detent
V396(L34)
3.07 Axle - F70 - 14 Tire
1-2 Up
7.4-10.9
38.1-50.4
2-1 Dn
9.6-5.7
39.5-23.5
2-3 Up
15.1-26.4
69.9-85.7
3-2 Dn
16.3-12.4
79.8-63.3
CHEVROLET CHASSIS SERVICE MANUAL
STEERING
9-33
POWER STEERING
INDEX
Page
General Description
. 9-33
Maintenance
and
Adjustments
9-33
Bleeding Hydraulic System
9-33
Fluid Level
. 9-33
Adjustments
. 9-34
Power Steering Gear
. . 9-34
Pump Belt Tension
9-34
Hydraulic System Checks
9-34
Component Replacement
and
Repairs
. 9-35
Power Steering Pump.
. 9-35
Power Steering Gear
9-36
Control Valve
and
Adapter Assembly
9.35
Power Cylinder
9.37
Power Steering Hoses
9.39
GENERAL DESCRIPTION
Two types
of
power steering
are
used
for 1967.
One
is
the conventional linkage type
for
Chevy
n and
Corvette
vehicles
and the
other
is the
integral gear type
for
Chevrolet, Chevelle,
and
Camaro.
For
both types
the
hydraulic pressure
is
provided
by an
engine-driven vane-
type pump.
On
the
Chevy
n and
Corvette linkage type power steer-
ing, hydraulic pressure
is
delivered through
a
hose from
the pump
to a
valve which senses
the
requirement
for
power assistance
and
supplies
the
power cylinder
ac-
cordingly.
The
steering gear used with this power steer-
ing
is the
same basic unit used
on
manually steered
vehicles;
it is
serviced
as
outlined
in the
manual steering
part
of
this section except
for
adjustment, which
is
covered
in the
following pages.
The
steering linkage also
is serviced the same
as
manual counterparts.
The Chevrolet, Chevelle
and
Camaro integral gear type
power steering
has the
hydraulic pressure delivered
from
the
pump through two hoses
to the
steering gear.
In
the power steering gear
the
steering shaft, hydraulic
valve, worm, and rack-piston
nut are all in
line making
a
compact
and
space saving assembly.
All oil
passages
are
internal within
the
gear except
the
pressure
and
return
hoses.
The steering gear
is a
recirculating ball system
in
which steel balls
act as a
rolling thread between
the
steering worm
and
rack-piston
nut. The
rack-piston
nut
is
all one
piece
and is
geared
to the
sector
of
the piston
shaft.
The
valve
is
contained
in the
gear housing elimi-
nating
the
need
of
bolts
or
seals
to
attach
a
separate
valve housing.
The valve
is an
open-center, rotary-type three
way
valve.
The
spool
is
held
in
neutral position by means
of a
torsion
bar. The
spool
is
attached
by
means
of
the stub
shaft
to one end of the
torsion
bar
and
to the
valve body
on
the
other
end.
Twisting
of the
torsion bar allows
the
spool
to
move
in
relation
to the
valve body thereby oper-
ating
the
valve.
MAINTENANCE
AND
ADJUSTMENTS
BLEEDING HYDRAULIC SYSTEM
1.
Fill
oil
reservoir
to
proper level and
let oil
remain
undistrubed
for at
least two minutes.
2.
Start engine
and run
only
for
about
two
seconds.
3.
Add
oil if
necessary.
4.
Repeat above procedure until
oil
level remains
con-
stant after running engine.
5. Raise front
end of
vehicle
so
that wheels
are off
the
ground.
6. Increase engine speed
to
approximately
1500 rpm.
7. Turn
the
wheels
(off
ground) right
and
left, lightly
contacting
the
wheel stops.
8. Add
oil if
necessary.
9. Lower
the car and
turn wheels right and left
on the
ground.
10.
Check
oil
level and refill
as
required.
11.
If oil is
extremely foamy, allow vehicle
to
stand
a
few minutes with engine
off and
repeat above
procedure.
,
a.
Check belt tightness
and
check
for a
bent
or
loose
pulley. (Pulley should
not
wobble with engine
running.)
b.
Check
to
make sure hoses
are not
touching
any
other parts
of the car,
particularly sheet metal.
c. Check
oil
level, filling
to
proper level
if
neces-
sary, following operations
1
through
10.
This
step
and
Step
"D" are
extremely important
as
low
oil
level and/or
air in the oil are the
most
frequent causes
of
objectionable pump noise.
d. Check
the
presence
of air in the oil. If air is
present, attempt
to
bleed system
as
described
in
operations
1
through
10. If it
becomes obvious
that
the
pump will
not
bleed after
a few
trials,
proceed
as
outlined under Hydraulic System
Checks.
FLUID
LEVEL
1.
Check
oil
level
in the
reservoir
by
checking
the dip
stick when
oil is at
operating temperature.
On
Chevelle models equipped with remote reservoir,
the reservoir should
be
maintained approximately
3/4 full when
oil is at
operating temperature.
2.
Fill,
if
necessary,
to
proper level with
GM
Power
Steering Fluid
or, if
this
is not
available, automatic
CHEVROLET CHASSIS SERVICE MANUAL
STEERING 9-34
Fig.
64-Over Center Adjustment
transmission fluid "Type A" bearing the mark
"AQ-ATF" followed by a number and the suffix
letter "A".
ADJUSTMENTS
POWER STEERING GEAR
Chevrolet, Chevelle, and Camaro
The over-center adjustment (fig. 64) is the only power
steering gear adjustment which can be made on the car.
However, in order to make this adjustment, it is also
necessary to check the combined ball and thrust bearing
preload.
If the vehicle is equipped with a tilt column it will be
necessary to disconnect the steering coupling to obtain a
torque reading of the column. This torque should then be
subtracted from any reading taken on the gear.
1.
Disconnect the pitman arm from the relay rod.
2.
Loosen the pitman shaft adjusting screw loeknut and
thread the adjusting screw out to the limit of its
travel through the side cover. '. •
3.
Disconnect steering column harness at chassis wir-
ing connector plug.
4.
Remove horn button.
5.
Turn the steering wheel through its full travel, then
locate the wheel at its center of travel.
6. Gheck the combined ball and thrust bearing preload
with an inch-pound torque wrench on the steering
shaft nut by rotating through the center of travel
(approximately 1/4 turn in each direction). Note the
highest reading.
7.
Tighten the pitman shaft adjusting screw and check
torque at steering shaft nut until over center preload
and total steering gear preload falls within speci-
fications. Refer to torque specifications at rear of
manual for correct torque values.
8. Install horn button. Connect steering column harness
at wiring connector plug.
Chevy II and Corvette
The steering gear used with power steering is adjusted
in the same manner as the manual steering gear.
PUMP BELT TENSION
1.
Loosen nut on pivot bolt and pump brace adjusting
nut.
CAUTION: Do not move pump by prying against
reservoir or by pulling on filler neck.
2.
Move pump, with belt in place until belt is tensioned
to specifications as indicated by Tool J-7316 (Fig-.
65).
3.
Tighten pump brace adjusting nut. Then tighten pivot
bolt nut.
HYDRAULIC SYSTEM CHECKS
The following procedure outlines methods to identify
and isolate power steering hydraulic circuit difficulties.
This test is divided into two parts. Test number one
provides means of determining whether power steering
system hydraulic parts are actually faulty. If test number
one results in readings indicating faulty hydraulic opera-
tion, test number two will identify the faulty part. Be-
fore performing hydraulic circuit test, carefully check
belt tension and condition of driving pulley. Strand
tension of belt should be 125 lbs. on new belts and 75 lbs.
on old belts, as indicated by Tool J-7316 (Fig. 65).
Test Number One—Oil Circuit Open
Engine must be at normal operating temperature. In-
flate front, tires to correct pressure. All tests are made
with engine idling, so adjust engine idle speed to correct
specifications listed in Section 6 and proceed as follows:
a. With engine not running, disconnect flexible pres-
sure line from pump and install Tool J-5176 as
Fig.
65— Checking Belt Tension with Tool J-7316
CHEVROLET CHASSIS SERVICE MANUAL
STEERING 9-35
Fig.
66—Power Steering Diagnosis
shown in Figure 66. Gauge must be between shut-
off valve and pump. Open shut-off valve,
b.
Remove filler cap from pump reservoir and check
fluid level. Fill pump reservoir to full mark on
dip stick. Start engine and, holding steering
wheel against stop, check connections at Tool
J-5176 for leakage. Bleed system as outlined
under Maintenance and Adjustments. Insert ther-
mometer (Tool J-5421) in reservoir filler open-
ing. Move steering wheel from stop to stop
several times until thermometer indicates that
hydraulic fluid in reservoir has reached tempera-
ture of 150° to 170°F.
CAUTION: To prevent scrubbing flat spots on
tires,
do not turn steering wheel more than five
times without rolling car to change tire-to-floor
contact area.
c. Hold steering wheel against a stop momentarily
and read pressure gauge. If the maximum pres-
sure is below specifications, a faulty hydraulic
circuit is indicated. To determine which part is
faulty, proceed with test number two.
Test Number Two—Oil Circuit Closed
a. Slowly turn shut-off valve on J-5176 to closed
position and read pressure indicated on gauge.
Quickly reopen valve to avoid pump damage, if
indicated pressure is less than specification,
pump output is below requirement and pump may
be considered faulty. If pressure indicated is
within specifications, it may be safely assumed
that the external hoses, connections, valve and
adapter or steering gear is at fault.
NOTE:
If pump proves faulty in test number
two,
test should be repeated after pump is re-
paired and installed in vehicle. This will provide
a means of checking the repairs made to the
pump and the condition of the steering gear or
valve and adapter which may also be faulty.
COMPONENT REPLACEMENT AND REPAIRS
POWER STEERING PUMP
Removal (Fig. 67)
1.
Disconnect hoses at pump. When hoses are discon-
nected, secure ends in raised position to prevent
drainage of oil. Cap or tape the ends of the hoses to
prevent entrance of dirt.
NOTE:
Chevelle with 396 engine uses a remote
reservoir. It is necessary to disconnect the
reservoir to pump hose before removing the
pump.
Hold a 1 qt. container under the reservoir
when the hose is removed to catch the fluid.
2.
Install two caps at pump fittings to prevent drainage
of oil from pump.
3.
Remove pump belt.
4.
On Corvette with 427 engine, loosen alternator ad-
justment and remove pump to alternator belt.
5. Remove pump from attaching parts and remove pump
from vehicle.
NOTE:
On Chevrolet and Chevy II equipped with
283 and 327 engine it may be necessary to re-
move pump brace.
6. Remove drive pulley attaching nut.
7. Remove pulley from shaft with Tool J-21239 (for
stamped pulleys) or Tool J-8433-1 with J-8433-2
adapter (for cast iron pulleys). Do not hammer
pulley off shaft as this will damage the pump.
Fig.
67—Power Steering Pump Mounting
CHEVROLET CHASSIS SERVICE MANUAL
STEERING 9-39
4.
Remove cotter pin, nut and ball stud at relay rod.
5. Remove the power cylinder from the vehicle.
Inspection
1.
Inspect the seals for leaks; if leaks are present,
replace the seals using the procedure outlined under
"Disassembly."
2.
Examine the brass fitted hose connection seats for
cracks or damage and replace if necessary.
3.
For service other than ball seat or seal replacement
and ball stud removal, replace the power cylinder.
4.
Check the frame bracket parts for wear.
Disassembly
1.
To remove the piston rod seal remove the snap ring;
then pull out on the rod, being careful not to spray
oil.
2.
Remove the piston rod scraper and scraper element,
back up washer and piston rod seal from the rod.
3.
At the ball stud end of the cylinder, remove the ball
stud seal.
4.
Remove the snap ring retaining the end plug with the
lube fitting.
5. Push on the end of the ball stud and remove the end
plug, spring, spring seat and ball stud.
6. Remove the "O" ring seal from the top lip of the
power cylinder ball stud opening.
7. If the ball seat is to be replaced, it must be pressed
out using Tool J-8937.
Assembly
1.
Reassemble the piston rod seal components by re-
versing the disassembly procedure. Apply a thin
coat of Lubriplate or equivalent on the inner sur-
faces of the seal and scraper before assembly.
2.
Reverse the disassembly procedure when reassem-
bling the ball stud.
3.
In each case be sure that the snap ring is securely,
seated in the ring groove.
Installation
1.
Install the power cylinder on the vehicle by reversing
the removal procedure.
2.
Reconnect the two hydraulic lines, fill the system
with fluid and bleed out air using the procedure out-
lined under "Maintenance and Adjustments." Grease
ball joint.
POWER STEERING HOSES
When servicing the power steering hoses be sure to
align the hoses in their correct position as shown in
Figure 71. On Chevelle models with 396 engine, install
the upper hose so that there is at least .6 inch clearance
between the hose and the Delcotron or the inner fender
skirt.
It is important that the power steering hoses be in-
stalled correctly. Hoses installed out of position may be
subjected to chafing or other abuses during sharp turns.
Always make hose installations with front wheels in
straight ahead position. Do not twist hoses unneces-
sarily during installation.
CAUTION: Do not start engine with any power
steering hose disconnected.
CHEVROLET CHASSIS SERVICE MANUAL
WHEELS AND TIRES 10-4
the road and it slips, grinding off the tread on the inside
half of the tire at an excessive rate. This type of tire
shows much the same appearance of tread wear as tire
wear caused by negative camber.
Second, the transfer of weight may also over-load the
outside tires so much that they are laterally distorted
resulting in excessive wear on the outside half of the
tire producing a type of wear like that caused by ex-
cessive positive camber.
Cornering wear can be most easily distinguished from
abnormal camber wear by the rounding of the outside
shoulder or edge of the tire and by the roughening of the
tread surface which denotes abrasion.
Cornering wear often produces a fin or raised portion
along the inside edge of each row in the tread pattern.
In some cases this fin is almost as pronounced as a
toe-in fin, and in others, it tapers into a row of tread
blocks to such an extent that the tire has a definite step
wear appearance.
The only remedy for cornering wear is proper in-
struction of owners.
Fig.
5 - Tire Rotatidh
Rotation
To minimize the possibility of tire noise and to equal-
ize tire wear, it is recommended that tires be inter-
changed every 6000 miles as shown in Figure 5 or more
frequently in the case of extremely heavy wear.
NOTE:
Rotate Corvette tires at 4000 miles or
sooner.
Interchanging tires will effectively prevent undue wear
on any particular tire. II tire interchanging is followed
as recommended above, all tires will have the same
number of miles in each wheel position at the end of the
fourth change. When interchanging tires, inspect for
signs of abnormal wear, bulging, etc., stones, glass, and
nails should be removed before reinstallation.
Noise
Noise caused by the normal action of tire treads on
various road surfaces is often confused with rear axle
gears or other noises in the car.
The determination of whether tires are causing the
noise complained of is relatively simple. The car should
be driven at various speeds and note taken of part
throttle, and sudden acceleration and deceleration. Axle
and exhaust noises show definite variations under these
conditions, while tire noise will remain constant. Tire
noise is, however, most pronounced at speeds of approx-
imately twenty or thirty miles per hour.
The tires may be further checked by driving the ear
over smooth pavement with the tires at normal pressure
and again over the same stretch of pavement when the
tires have been inflated to fifty pounds pressure. Reduce
the tires to normal pressure one at a time to determine
the faulty tire or tires. This high inflation pressure
should immediately be reduced to normal after test. If
the noise for which the test is being made is caused by
tires,.
it will noticeably decrease when the tire pressure
is increased, whereas axle noise should show no change
in volume.
If, on inspection, the tires on the front wheels are
found to be creating most of the noise the alignment of
the front wheels should be checked. Excessive tire noise
usually results from lower than recommended tire pres-
sure, incorrect alignment, uneven tire wear, or defective
(thumper) tire.
Cleaning
A great deal of ordinary road dirt which collects on
white sidewall tires may be sponged off with clear water
or a mild soap solution.
A good brand of whitewall tire cleaner, however, is
a quicker and more effective cleaner for removing dirt
and stains from whitewall tires and in many cases it
will remove stains and discoloration that the simpler
method of soap and water will not remove.
Under no circumstances should gasoline, kerosene or
any cleaning fluid containing a solvent derived from oil
be used to clean whitewall tires. Oil in any form is
detrimental to tire rubber and a cleaner with an oil base
will discolor or injure whitewall tires.
Change (W/Wheels)
To change the road wheels using the jack that comes
with the car, observe the following procedure:
1.
Set hand brake and block front wheels if rear wheel
is being changed.
2.
Remove hub cap or wheel disc and break wheel
mounting nuts loose.
3.
Place the jack as directed tinder, General Informa-
tion,
Section 0 and raise car until wheel clears
ground.
4.
Remove wheel mounting nuts and remove wheel from
hub or drum.
5. To replace road wheel, reverse the above instrue-
. tions. Proper torque on nuts is 55-75 ft. lbs.
torque (70-85 ft. lbs. for Corvette aluminum wheel
nuts).
CAUTION: On models equipped with discs, in-
dex the pilot hole in the disc on the valve stem.
(To insure that the anti-rotation notches in wheel
disc register on lugs in wheel rim.)
CHEVROLET CHASSIS SERVICE MANUAL