ENGINE 6-31
Chevy II
1.
Disconnect battery positive cable.
2.
Drain engine oil.
3.
Disconnect and remove starter.
4 Disconnect steering idler arm bracket at right hand
frame rail and swing steering linkage down for pan
clearance.
5.
Disconnect* exhaust pipes at manifolds and allow
pipes to hang free.
6. Remove oil pan and discard gaskets and seals.
Corvette
1.
Disconnect battery positive cable then remove oil
dipstick and tube.
2.
Raise and support vehicle then drain engine oil.
3.
Remove starter and flywheel underpan.
4.
Disconnect steering linkage idler at frame and lower
the linkage.
5.
Remove oil pan and discard gaskets and seals.
6. On Hi-Performance engines, the oil baffle must
be removed before additional operations can be
performed.
NOTE: On the 427 cu. in. engine, the oil pan
has three 1/4" x 20 attaching bolts at crankcase
front cqver. One located at each corner and one
at lower center.
Installation
1.
Thoroughly clean all gasket sealing surfaces.
NOTE: Use a new pan. gasket set.
2.
Install side gaskets on pan rails, using.gasket sealer
as a retainer.
3.
Install rear oil pan seal in groove in rear main
bearing cap with ends (fig. 9V) butting side gaskets.
4.
Install oil pan front seal in groove in .crankcaee front
cover, with ends butting side gaskets.
5.
If crankshaft was rotated while £>an was off, place
timing mark at 6:00 o'clock position.
6. Install oil pan and torque bolts to specifications.
NOTE: On 396 and 427 cu. in. engines, start
three 1/4" x 20 bolts into crankcase front cover
before tightening, any other pan bolts.
7.
Complete installation as follows:
Chevrolet
and Camaro
a. Using a suitable jack (and a block of wood to pre-
vent damaging oil pan) raise engine enough to re-
move 2" x 4" wood blocks, then lower engine.
b.
On vehicles equipped with automatic transmission
install converter housing underpan.
c. Install through bolts in engine front mounts.
d. Install and connect starter. Connect steering rod
at idler lever.
e. Lower vehicle and install fan blade.
f. Cbnnnect lower radiator hose, then install oil dip
stick tube and dip stick.
g. Connect distributor cap and battery positive
cable.
h. Fill radiator with coolant and fill engine with oil,
then start engine and check for leaks.
Chevelle
a. On vehicles equipped with automatic transmission
Fig.
9V - Oil Pan Gasket and Seal Location
install converter housing underpan.
b.
.Install starter.
c. Install, engine as outlined.
Chevy II
a. Connect exhaust pipe to manifold flange using new
packing seals.
b.
Connect steering idler arm bracket.
c. Connect starter wires..
d. Connect battery cable.
e. Fill with oil, start engine and check for leaks.
Corvette
a. Connect steering linkage.
b.
Install oil dip stick tube and dip stick then con-
nect battery cables.
c. Fill engine with oil, then start engine and check
for leaks.
OIL PUMP
Removal
1.
Remove oil pan as outlined.
2.
Remove pump to rear main bearing cap bolt and re-
move pump and extension shaft.
Installation
1.
Assemble pump and extension shaft to rear main
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE 6-37
Fig.
27V—Removing Camshaft
4.
Set dial indicator on zero, then rotate the damper
slowly, or attach an auxiliary starter switch and
"bump" the engine over, until the push rod is in the
fully raised position.
CAUTION: The primary distributor lead must
be disconnected from the negative post on the
coil and the ignition switch must be in the on
position. Failure to do this will result in a dam-
aged grounding circuit in the ignition switch.
5.
Compare the total lift recorded from the dial indica-
tor with specifications.
6. Continue to rotate the crankshaft until the indicator
reads zero. This will be a check on the accuracy of
the original indicator reading.
7.
If camshaft readings for all lobes are within specifi-
cations, remove dial indicator assembly.
8. Install and adjust valve mechanism as outlined.
Removal
1.
Remove valve lifters as outlined.
2.
Remove crankshaft front cover as outlined.
3.
Remove grille as outlined in Section 13.
4.
Remove fuel pump push rod as outlined * in Sec-
tion 6M.
5.
Complete camshaft removal as follows:
CAUTION: All camshaft journals are the same
diameter and care must be used in removing
camshaft to avoid damage to bearings.
Remove camshaft sprocket to camshaft bolts then
remove sprocket and timing chain together. Sprocket
is a light fit on camshaft. If sprocket does not come
off easily a light blow on the lower edge of the
sprocket (with a plastic mallet) should dislodge the
sprocket.
Install two 5/16" - 18 x 4" bolts in camshaft bolt
holes then remove camshaft (fig. 27V).
Installation
NOTE: Whenever a new camshaft is installed
CONVERTER
BOLT AREA -
DEPRESSED
SYNCHROMESH
RING
GEAR
TRANS.,
AUTOMATIC
Fig.
28V - Flywheel Installation (Typical)
coat camshaft lobes with Molykote or its
equivalent.
1.
Lubricate camshaft journals with engine oil and in-
stall camshaft.
2.
Install timing chain on camshaft sprocket. Hold the
sprocket vertical with the chain hanging down, and
orient to align marks on camshaft and crankshaft
sprockets. Refer to Figure 20V.
3.
Align dowel in camshaft with dowel in hole in cam-
shaft sprocket then install sprocket on camshaft.
Refer to Figure 25V.
4.
Draw the camshaft sprocket onto camshaft using the
mounting bolts. Torque to specifications.
5.
Lubricate timing chain with engine oil.
6. Install fuel pump push rod as outlined in Section 6M.
7.
Install grille as outlined in Section 13.
8. Install crankcase front cover as outlined.
9. Install valve lifters as outlined.
FLYWHEEL
Removal
With transmission and/or clutch housing and clutch
removed from engine, remove the flywheel.
Installation
1.
Clean the mating surfaces of flywheel and crankshaft
to make certain there are no burrs.
2.
Install flywheel on crankshaft and position to align
dowel hole of crankshaft flange and flywheel (fig.
28V).
NOTE: On Automatic Transmission equipped
engines, the flywheel must be installed with the
flange collar to transmission side (fig. 33V).
ENGINE MOUNTS
Engine mounts (fig. 34V) are the nonr adjustable type
and seldom require service. Broken or deteriorated
mounts should be replaced immediately, because of the
added strain placed on other mounts and drive line
components.
Front Mount Replacement
1.
Remove nut, washer and engine mount through-bolt.
2.
Raise engine to release weight from mount.
3.
Remove mount from engine.
CHEVROLET CHASSIS SERVICE MANUAL
CLUTCH
AND
TRANSMISSIONS
7-23
Assembly (Fig.
4X)
1.
With detent spring tang projecting
up
over
the 3rd
and
4th
shifter shaft cover opening install
the
first
and second detent
cam
onto
the
detent
cam
pivot
pin.
With
the
detent spring tang projecting
up
over
the
first
and
second shifter shaft cover hole install
the
3rd
and 4th
detent
cam,
NOTE:
The 1-2
detent
cam has a
.090" greater
contour
on the
inside detent notch.
2.
3.
Install detent
cam
retaining
"C"
ring
to
pivot shaft,
and hook spring into detent
cam
notches.
Install
1-2 and 3-4
shifter shaft assemblies
in
cover
being careful
not to
damage seals. Install both shift
forks
to
shifter shaft assemblies, lifting
up on
detent
cam
to
allow forks
to
fully seat into position.
4.
Install reverse detent ball
and
spring
to
cover, then
install reverse shifter shaft assembly
to
cover.
5.
Install outer shifter levers, flat washers, lock wash-
ers
and
bolts.
Installation
1.
Shift shifter levers into neutral detent (center) posi-
tion. Position cover gasket
on
case.
2.
Carefully position side cover into place making sure
the shift forks
are
aligned with their respective
mainshaft clutch sliding sleeves.
Install cover attaching bolts
and
tighten evenly
to
specified torque.
Remove filler plug
and add
lubricant specified
in
Section
0, to
level
of
filler plug hole.
3.
4.
ALUMINUM POWERGLIDE
INDEX
Page
General
Description
7-23
Maintenance
and
Adjustments .............. 7—23
Oil
Level Check
7-23
Periodic
Oil
Change
7-24
Periodic
Low
Band Adjustment
7-24
Manual
Shift Linkage Check
and
Adjust
7-24
Floor
Shift Linkage
7-25
Floor
Mounted Control Lever
and
Bracket
Assembly
7-29
Throttle
Valve Linkage
.... 7-29
Neutral
Safety Switch
.. . 7-30
Throttle
Return Check Valve (Dashpot)
7-30
Component
Parts Replacement
7-30
Transmission
Replacement .............. 7—30
Page
Other
Service Operations
7-32
Diagnosis
7-32
Warming
Up
Transmission
7-32
Shop
Warm
Up , 7-32
Road
Warm
Up 7-32
Checking
Fluid Level
and
Condition
7-32
Manual
Linkage
7-32
Oil
Leaks
7-33
Basic
Pressure Checks
7-33
Wide
Open Throttle Upshift Pressure Check
.... 7-33
Idle
Pressure
in
Drive Range
7-33
Manual
"Low"
Range Pressure Check .......
7-33
Drive
Range Overrun (Coast) Pressure
.
.......
7-33
Powerglide
Shift Points
. . 7-35
GENERAL DESCRIPTION
The case
and
converter housing
of the two
speed alumi-
num Powerglide Transmission
is a
single case aluminum
unit. When
the
manual control
is
placed
in the
drive
po-
sition,
the
transmission automatically shifts
to low
gear
for initial vehicle movement.
As the car
gains speed
and
depending
on
load
and
throttle position,
an
automatic shift
is made
to
high gear.
A
forced downshift feature
pro-
vides
a
passing gear
by
returning
the
transmission
to low
range.
The
oil
pump assembly
is a
conventional gear type
and
the
oil
pump housing
is of the
large diameter type acting
as
the
front bulkhead
of the
transmission.
The
torque
converter
is a
conventional three element welded design
bolted
to the
engine flywheel which drives through
a
two-
speed planetary gearset.
The
high clutch assembly
is
typical
of the
designs used
in
this type transmission.
The
aluminum Powerglide uses
an
output shaft mounted
gov-
ernor which requires
a
hole through
the
output shaft.
The
reverse clutch assembly
is a
multiple disc type clutch.
The steel plates
are
splined directly
to the
case while
the
face plates
are
splined
to the
internal
or
ring gear.
The
clutch piston operates within
the
rear portion
of the
case.
The internal diameter
of the
pistoh
is
sealed to
an
integral
hub portion
of the
case rear bulkhead.
The
outside
dia-
meter
is
sealed
to a
machined portion
of the
case.
The
piston
is
hydraulically applied
and is
released
by
separate
coil springs.
The
valve body assembly
is
bolted
to the
bottom
of the
transmission case
and is
accessible
for
service
by
removing
the oil pan
assembly.
The
valve
body consists
of an
upper
and
lower body located
on
either
side
of a
transfer plate.
The
vacuum modulator
is lo-
cated
on the
left rear face
of the
transmission case.
The
modulator valve bore
is
located
in the
upper valve body.
MAINTENANCE
AND
ADJUSTMENTS
OIL LEVEL CHECK
The transmission
oil
level should
be
checked period-
ically
as
recommended
in
Section
0. Oil
should
be
added
only when level
is on or
below
the
"ADD" mark
on the dip
stick with
oil hot or at
operating temperature.
The oil
level
dip
stick
is
located
at the
right rear
of the
engine
compartment. Fill with
oil
specified
in
Section
0.
In order
to
check
oil
level accurately,
the
engine should
be idled with
the
transmission
oil hot and the
control
lever
in
neutral (N) position.
It
is
important that
the oil
level
be
maintained
no
higher than
the
"FULL" mark
on the
transmission
oil
level gauge.
DO NOT
OVERFILL,
for
when
the oil
level
CHEVROLET CHASSIS SERVICE MANUAL
CLUTCH AND TRANSMISSIONS 7-24
is at the full mark on the dip stick, it is just slightly be-
low the planetary gear unit. If additional oil is added,
bringing the oil level above the full mark, the planetary
unit will run in the oil, foaming and aerating the oil. This
aerated oil carried through the various oil pressure pas-
sages (low servo, reverse servo, clutch apply, converter,
etc.) may cause malfunction of the transmission assem-
bly, resulting in cavitation noise in the converter and
improper band or clutch application. Overheating may
also occur.
If the transmission is found consistently low on oil, a
thorough inspection should be made to find and correct
all external oil leaks.
PERIODIC OIL CHANGE
The transmission oil should be changed periodically as
recommended in Section 0, and whenever transmission is
to be removed from the vehicle for repairs.
1.
Run engine for one minute in neutral prior to chang-
ing.
2.
Be sure vehicle is level or raise from the rear only.
3.
Remove the oil pan drain plug and allow oil to drain
thoroughly into a pan or can.
Replace drain plug and refill with approximately two
quarts of oil specified in Section 0.
NOTE: To refill the transmission, remove dip
stick from oil filler tube and refill transmission
with oil specified in Section 0 using filler tube
and funnel J-4264. Then, after shifting into all
ranges at idle speed to fill all oil passages, the
engine should be run at 800-1000 rpm with the
transmission in Neutral until the oil warms up,
then add oil as required to raise the fluid level
to the full mark on the dip stick. Refill capacity
is approximately 2 qts.
4.
Fig.
1PG - Adjusting Low Band Using J-21848
PERIODIC LOW BAND ADJUSTMENT (Fig. 1PG)
Low band adjustment should be periodically performed
at 12,000 mile intervals, or sooner, as necessary if op-
erating performance indicates low band slippage.
1.
Raise vehicle and place selector lever in neutral.
2.
Remove protective cap from transmission adjusting
screw.
3.
a. On Corvette Models: Drop left exhaust pipe for
clearance.
b.
On Chevelle Models: To gain clearance between
underbody and transmission, it may be necessary
to remove rear mount bolts from crossmember,
and move transmission slightly toward passenger
side of vehicle. .
4.
Loosen adjusting screw lock nut 1/4 turn and hold in
this position with wrench.
5.
Using Special Tool J-21848 adjust band to 70 in. lbs.
and back off four (4) complete turns for a band which
has been in operation for 6,000 miles or more,.or
three (3) turns for one in use less than 6,000 miles.
CAUTION: Be sure to hold the adjusting screw
lock nut at 1/4 turn loose with a wrench during"
the.adjusting procedure.
6. Tighten the adjusting screw lock nut to specified
torque.
CAUTION: The amount of back-off is not an
approximate figure, it must be exact.
MANUAL SHIFT LINKAGE CHECK & ADJUST
(Column Type)
1.
The shift tube and lever assembly must be free in the
mast jacket. See Section 9 for alignment of steering
column assembly if necessary.
2.
To check for proper shift linkage adjustment, lift
the transmission selector lever towards the steering
wheel. Allow the selector lever to be positioned in
drive (D) by the transmission detent.
NOTE: Do not use the indicator pointer as a
reference to position the selected lever. When
performing linkage adjustment, pointer is ad-
justed last.
3.
Release the selector lever. The lever should be in-
hibited from engaging low range unless the lever is
lifted.
4.
Lift the selector lever towards the steering wheel,
and allow the lever to be positioned in neutral (N) by
the transmission detent.
5.
Release the selector lever. The lever should now
be inhibited from engaging reverse range unless the
lever is lifted.
6. A properly adjusted linkage will prevent the selector
lever from moving beyond both the neutral detent, and
the drive detent unless the lever is lifted to pass
over the mechanical stop in the steering column.
7.
In the event that an adjustment is required, place
the selector lever in drive (D) position as determined
by the transmission detent. See Steps 2 and 3.
8. Loosen the adjustment swivel at the cross-shaft,
and rotate the transmission lever so that it contacts
the drive stop in the steering column.
9. Tighten the swivel and recheck the adjustment. See
2 and 6.
CHEVROLET CHASSIS SERVICE MANUAL
CLUTCH AND TRANSMISSIONS 7-31
with the "white" stripe painted on the engine
side of the flywheel outer rim, denoting the
"heavy" side of the engine.
1.
Mount transmission on transmission lifting equip-
ment installed on jack or other lifting device.
2.
Remove converter holding tool.
CAUTION: Do not permit converter to move
forward after removal of holding tool.
3.
Raise transmission into place at rear of engine and
install transmission case to engine upper mounting
bolts,
then install remainder of the mounting*bolts.
Torque bolts to 35 ft. lbs.
4.
Remove support from beneath engine, then raise
rear of transmission to final position.
5. Through flywheel cover opening align as closely as
possible the "white" flywheel balance mark stripe
and the "blue" painted stripe on the end of converter
cover and housing. If scribed during removal, align
scribe marks on flywheel and converter cover. In-
stall converter to flywheel attaching bolts. Torque
bolts to 15-20 ft. lbs.
6. Install converter under pan.
7. Reinstall transmission support crossmember to
transmission and frame.
8. Remove transmission lift equipment.
9. Connect propeller shaft to transmissions.
10.
Connect manual and TV control lever rods to
transmission.
11.
Connect oil cooler lines (if so equipped), vacuum
Fig.
13PG - Converter Holding Tool
modulato:* line, and speedometer drive cable to
transmission.
12.
Refill transmission through filler tube, using Funnel
J-4264 and following the recommended procedure
provided earlier in this section.
13.
Check transmission for proper operation and for
leakage. Check and, if necessary, adjust linkage.
CORVETTE POWERGLIDE TRANSMISSION
Replacement
1.
Disconnect battery ground cable.
2.
Remove ball end from transmission shift control
lever.
3.
Raise front and rear of vehicle.
4.
Insert a block of wood between the top of the dif-
ferential carrier housing and the underbody (to
prevent upward travel of the carrier when the car-
rier front support is disconnected).
5. Disconnect the differential carrier front support
from its frame bracket, by removing the nut on the
underside of the biscuit mount.
6. Pry the carrier downward to relieve load while re-
moving the two center mounting bolts from the
carrier front support. (To pry carrier downward
insert crowfoot end of a pry bar**hrough the open-
ing in the carrier front support, hooking end of bar
over top of the center mounting bolt pad cast in the
underside of the carrier).
7. Pivot carrier support downward for access to prop
shaft "U"-joint.
8. Disconnect prop shaft front and then rear
"U"
bolts.
9. Disconnect parking brake cable from ball socket at
idler lever located near center of underbody.
10.
Remove prop shaft by moving shaft forward.
11.
Remove left bank exhaust pipe.
12.
Remove right bank exhaust pipe and heat riser.
13.
Disassemble the transmission mount, as follows:
a. Remove the two bolts that attach rear mount
cushion to the rear mount bracket.
b.
Support engine under oil pan and raise engine to
remove load from rear mount cushion.
CAUTION: To avoid damage to oil pan, a suit-
able wide base, heavy wood platform should be
placed between the jack pad and the oil pan.
c. Remove the three transmission mount bracket-
to-crossmember bolts, then remove mount
bracket.
d. Remove the two bolts from mount pad to trans-
mission case and remove rubber mount cushion
and exhaust pipe "yoke".
14.
Disconnect oil cooler lines at transmission and
swing lines clear.
15.
Remove connector underpan.
16.
Remove converter to flywheel attaching bolts.
17.
At transmission disconnect vacuum modulator line
and speedometer cable.
18.
Disconnect transmission shift linkage from trans-
mission gearshift control lever. Remove shift lever.
19.
At transmission, remove throttle valve linkage and
disconnect neutral safety switch linkage, also re-
move the gearshift control linkage.
20.
Remove neutral safety switch from transmission
control bracket.
CHEVROLET CHASSIS SERVICE
CLUTCH AND TRANSMISSIONS 7-32
21.
Remove transmission output shaft slip yoke and in-
sert a plastic shipping plug in end of extension to
prevent spillage of transmission fluid.
NOTE:
The yoke is removed to avoid tearing
the heat reflecting pad on the underbbdy, when
the transmission is being removed.
22.
Remove bright metal ignition shielding from dis-
tributor area.
23.
Remove the transmission dip stick and tube
assembly.
24.
Disconnect transmission vacuum modulator line at
distributor advance line tee.
25.
Position transmission hoist under transmission and
attach safety chain to transmission.
26.
Remove transmission converter housing-to-engine
attaching foolts and slide transmission rearward.
NOTE:
Observe converter when moving trans-
mission rearward. If converter does not move
with the transmission, pry it free of flywheel
before proceeding.
27.
Install converter retaining strap.
28.
Lower and remove transmission from vehicle by
tilting the front down and to the right while inter-
mittently lowering the transmission to facilitate its
• removal.
29.
Reinstall transmission assembly by performing the
above steps in reverse order.
Bolt Torques
Transmission Case to Flywheel
Housing Bolts 35 ft. lbs.
Converter to Flywheel Bolts. . , . . 35 ft. lbs.
OTHER SERVICE OPERATIONS
Although certain operations, such as oil pan or gasket
replacement, valve body, governor, filler pipe "O" ring,
speedometer drive gear, case extension "0" ring and
rear oil seal, vacuum modulator, and servo cover or
gasket service may be performed from underneath the
vehicle without removing the Powerglide; their service
procedure is covered in the Passenger Overhaul Manual
and is not repeated here. Refer to the- Powerglide Sec-
tion of the Passenger Overhaul Manual for all other
service operations not covered here.
DIAGNOSIS
Proper operation of the Powerglide transmission may
be affected by a number of factors, all of which must be
considered when trouble in the unit is diagnosed.
Proper trouble diagnosis can only be accomplished
when performed in a thorough step by step procedure.
The following procedure has been devised and tested and
is recommended for all trouble diagnosis complaints and
if the service man will follow this checking procedure,
accurate and dependable diagnosis may be accomplished.
This will result in a savings of time, not only to the
service man, but to the customer as well.
WARMING UP TRANSMISSION
Before attempting to check and/or correct any com-
plaints on the Powerglide transmission it is absolutely
essential that the oil level be checked and corrected if
necessary. An oil level which is either too high or too
low can be the cause of a number of abnormal conditions
from excessive noise to slippage in all ranges.
It must be remembered that cold oil will slow up the
action of the hydraulic controls in the transmission. For
this reason a trouble or oil leak diagnosis should not be
attempted until the transmission has been warmed up by
either of the following procedures:
Shop Warm Up
1.
Connect tachometer to engine.
2.
Set parking brake tight and start engine.
3.
Place selector light in
"D"
(drive) range.
4.
Adjust carburetor idle speed adjusting screw to run
engine at approximately 750 rpm and operate in this
manner for two minutes. At the end of two minutes
of operation, the transmission will be sufficiently
warmed up for diagnosis purposes.
NOTE:
At this point, readjust the engine idle
speed to 450-475 rpm in
"D"
range.
Road Warm Up
Drive the car approximately 5 miles with frequent
starts and stops.
NOTE:
At this point, make sure the engine idle
speed is set to 450-475 rpm in
"D"
range.
CHECKING FLUID LEVEL AND CONDITION
After transmission has been warmed up, check the
fluid level with the engine idling, parking brake set and
control lever in "N" (neutral). If the fluid level is low,
add fluid to bring level up to the full mark on gauge rod,
CAUTION: If fluid level is too high, fluid may
be aerated by the planet carrier. Aerated fluid
will cause turbulence in the converter which will
result in lost power, lower stall speed and lower
pressures in control circuits. Lower fluid level
to full mark, then shut off engine to allow air
bubbles to work out of fluid.
When checking oil level, aburned smell and discolora-
tion indicate burned clutches or bands and the transmis-
sion 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
CHEVROLET CHASSIS SERVICE MANUAL
STEERING 9-2
Fig.
1—Cover
Attaching Bolts—Chevy li Shown
ADJUSTMENTS
STEERING
GEAR
Before any adjustments are made to the steering gear
in an attempt to correct such conditions as shimmy,
loose or hard steering etc., a careful check should be
made of front end alignment, shock absorbers, wheel
balance and tire pressure for possible cause.
Correct adjustment of the steering gear is very im-
portant. Perform adjustments following the sequence
listed below,
1.
Remove pitman arm nut and mark relation of pitman
arm position to sector shaft. Remove pitman arm
with Tool J- 6632 as shown in Figure 2.
2.
Loosen the pitman shaft lash adjuster screw locknut
and turn the adjuster screw a few turns in a counter-
clockwise direction (fig. 3). This removes the load
Fig. 2—Removing Pitman Arm
imposed on the worm bearings by the close meshing
of rack and sector teeth. Turn steering wheel gently
in one direction until stopped by gear, then back away
about one turn.
CAUTION: Do not turn steering wheel hard
against stops when steering relay rod is discon-
nected as damage to ball guides may result.
3.
All except Corvette and telescopic columns:
a. Disconnect steering column harness at chassis
wiring connector plug.
b.
Remove horn cap or ornament and using an inch
pound torque wrench and socket on steering wheel
nut, measure torque required to keep the wheel
in motion.
LASH ADJUSTER
SCREW
LOCK NUT
WORM BEARING
ADJUSTER
\
WORM
ADJUSTER
Fig.
3—Steering Gear Adjustment Points
CHEVROLET CHASSIS SERVICE MANUAL
STEERING 9-3
Fig.
4-Checking Wheel PuI!-Corvette
c. If torque does not lie within limits given in speci-
fications at rear of manual, adjustment is
necessary.
4.
Corvette and telescopic columns:
a. Use Tool J-5178 to measure.pull at rim of wheel
required to keep wheel in motion (fig. 4).
b.
If pull does not lie within limits given in specifi-
cations in rear of manual, adjustment of worm
bearings is necessary.
NOTE:
If vehicle is equipped with a tilt steer-
ing column, it will be necessary to disconnect
the steering coupling to obtain a torque reading
of the steering column. This torque should then
be subtracted from any reading taken on the
gear.
5. To adjust worm bearings, loosen worm bearing ad-
juster locknut and turn worm bearing adjuster shown
in Figure 3 until there is no perceptible end play in
worm. Check pull at steering wheel, readjusting: if
necessary to obtain proper pull. Tighten locknut and
recheck pull. If the gear feels "lumpy" after adjust-
ment of worm bearings, there is probably damage in
the bearings due to severe impact or to improper
adjustment and the gear must be disassembled for
replacement of damaged parts.
6. After proper adjustment of worm is obtained and all
mounting bolts securely tightened, adjust lash ad-
juster screw. First turn the steering wheel gently
from one stop all the way to the other, carefully
counting the total number of turns. Then turn wheel
back exactly half way, to center position. Turn lash
adjuster screw clockwise to take out all lash in gear
teeth, and tighten locknut. Check pull at steering
wheel taking highest reading as wheel is turned
through center position. See specifications in rear of
manual for proper sector lash adjustment. Readjust
if necessary to obtain proper pull.
NOT MORE THAN
T/a INCH FROM
CENTERLINE
Fig.
5—Steering Wheel Alignment
NOTE:
If maximum specification is exceeded,
turn las£ adjuster screw counterclockwise, then
come up on adjustment by turning the adjuster in
a clockwise motion.
7. Tighten locknut then recheck pull, as it must lie be-
tween specified readings.
Fig.
6—Adjusting Steering Ratio—Corvette
CHEVROLET CHASSIS SERVICE MANUAL