CORVETTE BODY 1B-32
1.
Panel - Underbody
2.
Panel - Wheel Housing
Closing - Right Hand
3. Shield - Right Hand Splash
4.
Nut
5. Panel - Underbody Closing
Fig.
68—Underbody Construction
6. Shield - Left Hand Splash
7. Nut
8. Reinforcement - Body
Mounting
9. Panel - Wheel Housing Closing
- Left Hand
10.
Plate - Seat Belt Mounting
11.
Bracket - Center Cover
Mounting
12.
Plate - Transmission Control
Boot Retaining
the broken or cracked portion. Side of "V" should
have a shallow pitch for maximum bonding surface.
A belt sander with a vacuum attachment will mini-
mize the dust problem, Figure 75.
4.
If rear of damage is accessible, use a button-type
repair. Clean back of area to permit the use of
laminate (resin-saturated glass-cloth) on both sides
of damaged area.
5. Cut fiberglass cloth to size. Make certain a minimum
of five layers is cut for the average repair.
6. Mix resin and hardener, 1 part hardener to 4 parts
resin. Add Thixatrope to the mix to give the mix
body and reduce the "runniness" of the material.
CAUTION: Cleanliness is most important. Be
certain all containers are dry and clean and
the resin and hardener cans are kept closed
when not in use. Do not use waxed cups for
mixing and do not allow resin to enter hardener
can or vice versa.
7. Saturate layers of fiberglass (fig. 76). Place lami-
nate over damage area. Smooth out wrinkles and
make sure general contour of area is maintained,
Figure 77.
8. Apply heat to repair area. Heat lamps are recom-
mended, used at least 12" away from repair. Allow
.15 to 20 minutes curing time. Trim repair to shape
at gel stage.
9. After the repair is cured, grind, file or sand to
contour. Files other than body files may be more
suitable. A belt sander with a vacuum cleaner at-
tachment will minimize the dust problem. Feather
edge and finish sand.
NOTE:
After Resin Repair, small pits or ir-
• regularities may appear in finished surface.
Imperfections should be repaired using the
Plastic Solder Repair Kit.
SPECIFIC REPAIRS
Scratched Panels, Spot Refinishing
In many instances, a scratched panel will involve only
a paint refinishing job. Figure 78 shows the top of a
fender panel which has been scratched through to the
plastic.
CHEVROLET CHASSIS SERVICE MANUAL
SECTION 2
FRAME
INDEX
Page
General Description 2-1
Chevrolet 2-1
Cheveile '. 2-1
Repair Procedures 2-1
Page
Checking Frame Alignment 2-1
Car Preparation 2-1
Tramming Sequence 2-1
Reference Point Dimensions 2-1
GENERAL DESCRIPTION
CHEVROLET AND CHEVELLE
Frames used on Chevrolet and Cheveile lines are basi-
cally the same, consisting of full length right and left
side members joined laterally by crossmembers. Sev-
eral different frames are used in each line to meet the
various vehicle size and function requirements but the
basic shape for each line remains the same. Differences
between frames in a given line exist only in metal gauge,
part size and numbers of parts necessary to meet the
particular structural requirements of the models
involved.
CORVETTE
The Corvette frame is a rigid perimeter unit, with five
crossmembers. From the rear kick-up forward, trap-
azoidal shaped, closed side members outline and protect
the passenger compartment. At the cowl area, the side
members curve inward in a sweeping "S" shape, to pro-
vide a sturdy foundation for the engine mounts and clear-
ance for front wheel movement. From the kick-up
rearward, box-sectioned side rails provide fore and aft
support for the rear axle and suspension. Lateral sup-
port is provided by five variously shaped welded-in
crossmembers, including the front unit, which formerly
was bolted-in.
CHEVY II AND CAMARO
Underbody alignment checking procedures will be found
in the Body Service Manual.
REPAIR PROCEDURES
CHECKING FRAME ALIGNMENT
Vehicles involved in an accident of any nature which
might result in a "swayed" or "sprung" frame should
always be checked for proper frame alingment in addi-
tion to steering geometry and wheel alignment.
CAR PREPARATION
Preparing the car for the frame alignment check in-
volves the following:
1.
Place the car on level surface.
2.
The weight of the car should be supported at the
wheel locations.
3.
A visual damage inspection should be made to elim-
inate needless measuring. Obviously damaged or
misaligned areas can often be located by sight.
TRAMMING SEQUENCE
When checking a frame for alignment in case of dam-
age,
the first step is horizontal "X" checking with a
tram from similar given points on opposite side of the
frame.
Frame alignment checks on all models should be made
with the tram points set at the center of each locating
point indicated and the cross bar level to insure
accuracy.
When "X" checking any section of the frame, the
measurements should agree within 3/16". If they do not,
it means that corrections will have to be made.
If a tram gauge is not available, the "plumb bob"
method of checking may be used. To assure any degree
of accuracy when using this method, the vehicle should
be on a level floor.
By using this method, it is only necessary to have a
#
piece of cord attached to an ordinary surveyor's plumb
bob.
When measuring the distance between two points,
the free end of the cord should be placed on the reference
point allowing the plumb bob to hang on the floor. A check
mark should be made on the floor just under the tip of
the plumb bob. This operation should be repeated at all
reference points. With these points located on the floor,
they may easily be measured with a rule.
The second step is checking the vertical dimensions
from the datum plane to the points to be trammed. With
the proper settings the tram bar will be on a plane
parallel to that of the frame. The exception to this would '
be when one of the reference locations is included in the
misaligned area; then the parallel plane between the
frame and the tram bar may not prevail. After com-
pletion of the repairs, the tram gauge should be set at
the specified dimension to check the accuracy of the re-
pair operation.
ALIGNMENT REFERENCE POINT DIMENSIONS
Dimensions to holes are measured to dead center of
the holes and flush to the adjacent surface metal.
CHEVROLET CHASSIS SERVICE MANUAL
REAR SUSPENSION AND DRIVE LINE 4-7
tioned vertically in the torque arm before ap-
plying pressure to the puller screw.
5.
Remove shim and bearing spacer from spindle
support.
6. Note size of shim used. If dial indicator reading
was more than
.008",
select a shim thinner by the
amount needed to bring end play within limits. If
dial indicator reading was less than
.001",
select a
shim thicker by the amount needed to bring end play
within limits.
NOTE: Shims are available in thicknesses from
.097"
to .148" in increments of
.003".
EXAMPLE: Bearing end play reading obtained
on dial indicator was
.011",
.003" over limit.
Bearing shim removed from spindle measures
.145".
New shim installed measures .139", .006"
smaller. End play is now decreased by .006" and
is
.005",
which is within the .001" to .008" limit.
7.
After determining shim thickness, install bearing
spacer and shim on spindle. Position spindle in
spindle support.
8. Press inner bearing race and roller assembly on
spindle as follows.
a. Position Tool J-4731 over spindle and against
bearing inner race.
b.
Position washer and spindle nut on spindle and
proceed to tighten nut until bearing is forced on
spindle sufficiently to allow spindle drive flange
to be installed (fig. 13). Remove spindle nut,
washer and Tool
J-4731.
Discard nut and use a
new one for final assembly.
9. Position drive flange over spindle, making sure
flange is aligned with spindle splines. Install washer
Fig.
13—Installing Drive Spindle to Support (Corvette)
and nut on spindle then tighten nut to specifications
and install cotter pin. If specified torque does not
permit cotter pin insertion, tighten nut to next flat.
10.
Seat spindle support outer seal in bore by using
screw driver, or other suitable tool, to press against
metal portion of seal.
11.
Install brake disc and caliper. Refer to Section 5
for details of brake disc and caliper installation.
12.
Install axle drive shaft, wheel and tire assembly,
adjust camber cam to original position and torque
all components to specifications.
COMPONENT PARTS REPLACEMENT
(Chevrolet, Chevelle, Chevy II and Camaro)
COIL SPRING
Chevrolet
Removal
To remove either or both rear coil springs proceed
as follows.
1.
Raise rear of vehicle and place jack stands under
frame. Support vehicle weight at rear, using either
a jack or post of twin-post hoist under axle.
2.
Remove both rear wheels from vehicle.
3.
With the car supported as in Step 1, so that the rear
springs are compressed by weight of vehicle; per-
form the following:
a. Disconnect both rear shock absorbers from the
anchor pin lower attachment.
b.
Loosen the upper control arm(s) rear pivot bolt
(do not remove the nut).
C. Loosen both the left and the right lower control
arm rear attachment (do not disconnect from axle
brackets).
d. Remove the rear suspension tie rod from the
stud on the axle tube.
4.
At the lower seat of both rear coil springs, slightly
loosen the nut on the bolt that retains the spring and
seat to the control arm. When the nut has been
backed off the maximum permissible, all threads of
the nut should still be engaged on the bolt.
CAUTION: Under ,no condition should the nut,
at this time, be removed from the bolt in the
seat of either spring.
5.
Slowly lower the support (jack or hoist post) that has
been in place under the rear axle, thereby allowing
the axle to swing down, carrying the springs out of
their upper seat and providing access for spring
removal.
6. Remove the lower seat attaching parts from each
spring, then remove the springs from the vehicle
(fig. 14).
Installation
1.
Position the springs in their upper seat so that end
of top coil is 3/8" ± 1/8" from end of stop. Install
the lower seat parts on the control arm, with the nut
finger tight on the spring retainer bolt.
NOTE: Omit the lock washer under the special
high carbon bolt, so that sufficient bolt thread
will be available to start the nut. The lock
washers will be installed later (in Step 4).
2.
By alternately raising the axle slightly and then
re-snugging the nut on each spring lower seat bolt,
move the axle upward until vehicle weight is fully
CHEVROLET CHASSIS SERVICE MANUAL
REAR SUSPENSION AND DRIVE LINE 4-20
Fig.
51—Shock Absorber Installation (Corvette)
6. Tap new spindle inner grease seal into seal bore
and install deflector over support inner end.
Installation
1.
Position support over torque arm bolts with strut
rod fork toward center of vehicle and downward.
Place backing plate over studs and torque nuts to
specifications.
2.
Connect parking brake cable to actuating lever.
3.
Install drive spindle assembly as outlined previously
in this section under "Wheel Bearing Adjustment".
4.
If new spindle support or associated parts are in-
stalled, determine correct shim size as follows.
a. Assemble spindle to support, using a .145" shim.
b.
Check bearing adjustment and correct as neces-
sary, following adjustment procedures previously
outlined.
DIFFERENTIAL CARRIER SUPPORT
BRACKET REPLACEMENT
1.
Place a 1/2" thick block of wood or steel between
nose of differential carrier and floor pan. This will
prevent carrier from twisting upward when support
bracket is disconnected.
2.
Remove carrier support-to-crossmember attaching
bolt.
3.
Remove nut from both of the bracket-to-carrier
through bolts.
4.
Slide bolts to one side until bolt head contacts floor
well. Mark the floor well at this point and drill a
3/4"
diameter hole for each bolt in floor well and
remove bolts.
5. Assemble carrier support bracket by reversing
above procedure. Torque all affected parts to
specifications.
6. Insert plastic plugs from the inside of the floor well
holes to prevent dust and water entry.
STRUT ROD SHAFT STRUT ROD
CAMBER CAM
AND BOLT
Fig.
52—Strut Rods (Corvette)
SHOCK ABSORBER (Fig. 51)
Removal
1.
Disconnect shock absorber upper mounting bolt*
2.
Remove lower mounting nut and lock washer.
3.
Slide shock upper eye out of frame bracket and pull
lower eye and rubber grommets off strut rod mount-
ing shaft.
4.
Inspect grommets and shock absorber upper eye for
excessive wear.
Installation
1.
Slide upper mounting eye into frame mounting
bracket and install bolt, lock washer and nut.
2.
Place rubber grommet, shock lower eye, inboard
grommet, washers and nut over strut rod shaft.
3.
Torque nuts to specifications.
STRUT ROD AND BRACKET (Fig. 52)
Removal
1.
Raise vehicle enough to provide working clearance.
2.
Disconnect shock absorber lower eye from strut
rod shaft.
3.
Remove strut rod shaft cotter pin and nut. With-
draw shaft by pulling toward front of vehicle (fig. 53).
4.
Mark relative position of camber adjusting cam and
Fig.
53-Removing Strut Rod Shaft (Corvette)
CHEVROLET CHASSIS SERVICE MANUAL
REAR SUSPENSION AND DRIVE LINE 4-25
Fig.
69—Removing Crossmember (Corvette)
4.
Remove bolts securing carrier cover to cross-
member.
5.
Inspect rubber isolation mounts for aging and re-
place where necessary.
Repairs—Isolation Mount
1.
Bend back isolation mount tabs to allow mount re-
moval (fig. 70).
2.
Place crossmember on a suitable support and press
mount out of arm using a piece of suitable size pipe
or tubing on outer shell or inner insert.
3.
Place new mount into position on crossmember,
compress outer sleeve and press mount into place
until it is fully and squarely seated.
4.
After installation, bend over locking tabs.
Installation
1.
Install carrier cover to crossmember and torque
bolts to specifications.
2.
Raise crossmember into position and install mount-
ing bolts. Torque bolts to specifications.
3.
Install differential carrier assembly as outlined
under Differential Carrier
-
Installation in this
section.
4.
Install wheels and tires, remove frame supports and
lower vehicle.
STABILIZER SHAFT REPLACEMENT
1.
Raise rear of vehicle and support at frame side rail
with stand jacks.
2.
Disconnect stabilizer shaft at both torque arms (fig.
71).
Remove stabilizer shaft brackets from the
frame and withdraw assembly from vehicle.
ISOLATION MOUNT
CROSSMEMBER
BEND OVER TABS AFTER INSTALLATION
Fig.
70—Crossmember Mount Cross-Section (Corvette)
3.
Inspect bushings for signs of deterioration, and in-
spect shaft for bends, breaks or other defects - do
not attempt to straighten shaft - replace parts as
deemed necessary.
4.
Position bushings on shaft and loosely install shaft
to torque arms and at frame brackets.
5.
Align shaft to assume proper placement when bolts
are torqued, and torque attaching bolts to
specifications.
Fig.
71—Stabilizer Shaft Installation (Corvette)
CHEVROLET CHASSIS SERVICE MANUAL
BRAKES 5-6
Fig.
9—Brake Pedal Free Movement
one or two points in appropriate direction, replace
retainer, and re-inspect.
6. Place steel tube connector in hose fitting and tighten
securely.
7. Bleed all brakes as outlined in this section.
8. Do not tighten male end (wheel cylinder end) once
the other end is fixed. If necessary to tighten male
1 end, disconnect hose at opposite end, then reconnect
following above procedure.
Hydraulic Brake Tubing
Hydraulic brake tubing is a double layer annealed
steel terne plate tubing which resists corrosion and has
the physical strength to stand up under the high pr.es-
Fig.
11—Hydraulic Brake Tube Double Flaring Tool
sures which are developed when applying the brakes. In
making up hydraulic brake pipes, it is important that
the proper flaring tool be used to flare the ends of the
tubing for the compression couplings. Unless the tubing
is properly flared, the connections will leak and the
brakes will become ineffective.
CAUTION: When necessary to replace brake
tubing, always use special steel tubing which
is designed to withstand high pressure and re-
sist corrosion. Ordinary copper tubing is not
satisfactory and should not be used.
This safety steel tubing must be double-lap flared at
the ends in order to produce a strong leak-proof joint.
The brake tube flaring. Tool J-8051 (fig. 11) is used to
form the double-lap flare.
Figure 12 shows two pieces of tubing, one with single-
lap flare "A" and the other with double-lap flare "B".
It will be noted that the single-lap flare in "A" split
the tubing while the one shown in "B" is well-formed and
unbroken due to the reinforcement of the double wall.
The following procedure should be followed in making
up hydraulic brake pipes.
Double Lap Flaring
1.
Clamp the tubing in the proper size die blocks with
the flat ends of the blocks toward the end of the
tubing to be cut off. Cut the end of the tubing flush
and square. Using a mill file, dress tubing and
square ends.
Fig.
10-Brake Line Support Bracket
Fig.
12—Single and Double Lap Flaring
CHEVROLET CHASSIS SERVICE MANUAL
BRAKES 5-7
LATCH PLATE
DIE BLOCK
TUBE
UPSET FLARE PUNCH
RAM GUIDE
STOP PLATE
Fig.
13—Flaring Operation--Position ing Tubing
2.
Remove the tubing from the die block and deburr
the inside and outside edges.
3.
Install compression couplings on tubing and dip end
of tubing to be flared in hydraulic fluid. This lubri-
cation results in better formation of the flare.
4.
Place on-half of the die blocks in the tool body with
the counterbored ends toward the ram guide. Now
lay the tubing in the block with approximately 1/2"
protruding beyond the end.
Fit the other half of the block into the tool body,
close the latch plate and tighten the nuts "finger
tight".
5. Select the correct size upset flare punch. One end
of this punch is counterbored or hollowed out to
gauge the amount of tubing necessary to form a
double lap flare. Slip the punch into the tool body
with the gauge end toward the die blocks. Install the
ram; then tap lightly until the punch meets the die
, blocks and they are forced securely against the
stop plate (fig. 13).
6. Using the supplied wrench, draw the latch plate
nut down tight to prevent the tube from slipping.
Tightening the nuts alternately (beginning with the
nut at the closed hole in the plate) will prevent
distortion of the plate. Remove the punch and the
ram. Now reverse the punch and put it back into the
tool body. Install the ram and tap it lightly until
the face of the upset flare punch contacts the face
of the die blocks (fig. 14). This completes the
first operation. Remove the ram and the punch.
7. To complete the flare, insert the pointed finish
flare punch and the ram into the tool body. Tap
the ram until a good seat is formed (fig. 15).
NOTE:
The seat should be inspected at inter-
vals during the finishing operation to avoid
over-seating.
LATCH
DIE BLOCK
TUBE
UPSET FLARE PUNCH
RAM GUIDE
RAM
1ST OPERATION
UPSET FLARE
PUNCH
2ND OPERATION
FINISH FLARE
PUNCH
Fig.
15—Flaring Operation—First and Second Flare
BRAKE ADJUSTMENT
Service Brake
Although the brakes are self-adjusting, a preliminary
or initial adjustment may be necessary after the brakes
have been relined or replaced, or whenever the length
of the adjusting screw has been changed. The final
adjustment is made by using the self-adjusting feature.
1.
With brake drum off, disengage the actuator from
the star wheel and rotate the star wheel by spinning
or turning with a small screw driver.
2.
Recommended
a. Use special Tool J-21177; Drum-to-Brake Shoe
Clearance Gauge, to check the diameter of the
brake drum inner surface (fig. 16).
Fig.
14—Flaring Operation—First Flare
Fig.
16—Using Drum-to-Brake Shoe Clearance
Gauge Tool J-21177
CHEVROLET CHASSIS SERVICE MANUAL
BRAKES 5-22
2.
Replace ail push rods and pull back springs.
3.
Connect hose or line to wheel cylinder.
NOTE:
If replacing front wheel cylinder, con-
nect hose and inspect installation as outlined in
"Hydraulic Brake Hose Replacement".
4.
Install drum and wheel.
5. Bleed brakes as outlined in this section.
ANCHOR PIN
Front Wheel
1.
Raise front of vehicle and place on jack stands.
2.
Remove wheel and drum as outlined in this section.
3.
Remove brake shoe pull back springs, link and guide
plate.
4.
Disengage anchor pin lock and remove anchor pin by
turning counterclockwise.
5. Place new lock plate on anchor pin and pass pin
through the hole in flange plate and screw into tapped
hole in spindle support.
6. Torque pin to 130 lb. ft. and lock by peening over
washer tabs.
7. Install brake shoe guide plate, link and pull back
springs.
8. Adjust brakes, install drum and wheel as outlined
in this section. Test brake operation.
Rear Wheel
Two type anchor pins are used in production for the
rear wheels. The riveted type is not serviced and if
failure or damage should occur to either the anchor
pin or flange plate, both parts will have to be replaced
and the threaded type anchor pin used.
Threaded Type
1.
Raise rear of vehicle and place on jack stands,
2.
Remove wheel and drum as outlined in this section.
3.
Remove brake shoe pull back springs, link and guide
plate.
4.
Remove anchor pin retaining nut and washer and
remove pin from flange plate.
5. Position anchor pin to flange plate, install lock
washer and nut, and torque pin to 80 lb. ft.
6. Install brake shoe guide plate, link and pull back
springs.
7. Adjust brakes and install drum and wheel as outlined
in this section.
8. Test brake operation.
BRAKE DRUMS
Front brake drums are the demountable type; that is,
they can be removed without removing the hub. Rear
brake drums are demountable and may be removed
wihtout removing the axle shaft.
A lanced "knock out" area (fig. 34) is provided in
the web of the brake drum for servicing purposes in
the event retracting of the brake shoes is required in
order to remove the drum.
A small screw driver or hooked wire may be inserted
to disengage the automatic adjuster actuating lever so
the star wheel may be turned.
Removal
1.
Raise vehicle and place on jack stand.
2.
Remove wheel and tire assembly, back off brake
adjustment and remove drum.
Inspection and Reconditioning
Whenever brake drums are removed they should be
thoroughly cleaned and inspected for cracks, scores,
deep grooves, and out-of-round. Any of these conditions
must be corrected since they can impair the efficiency
of brake operation and also can cause premature failure
of other parts.
Smooth up any slight scores by polishing with fine
emery cloth. Heavy or extensive scoring will cause
excessive brake lining wear and it will probably be
necessary to rebore in order to true up the braking
surface.
An out-of-round drum makes accurate brake shoe
adjustment impossible and is likely to cause excessive
wear of other parts of brake mechanism due to its
eccentric action.
A drum that is more than .008" out-of-round on the
diameter is unfit for service and should be rebored.
Out-of^round, as well as taper and wear can be ac-
curately measured with an inside micrometer fitted
with proper extension rods.
If drum is to be rebored for use with standard size
brake facings which are worn very little, only enough
metal should be removed to obtain a true smooth braking
surface.
If drum has to be rebored more than .020" over the
standard diameter, it should be rebored to .060" diameter
oversize and the brake facing should be replaced with
.030"
oversize facings.
A brake drum must not be rebored more than .060"
over the maximum standard diameter, since removal
of more metal will effect, dissipation of heat and may
cause distortion of drum. Chevrolet brake facing is
not furnished larger than .030" oversize and this will
not work efficiently in drums bored more than .060"
oversize.
Brake drums may be refinished either by turning or
grinding. Best brake performance is obtained by turning
drums with a very fine feed. To insure maximum lining
life,
the refinished braking surface must be smooth and
free from chatter or tool marks, and run-out must not
exceed .005" total indicator reading.
Cleaning
New brake drums in parts stock are given a light.
coating of rust proofing oil to prevent the formation of
rust on the critical braking surfaces during the time
that the drums are in storage.
This rust proofing oil must be carefully removed
before the drum is placed in service to prevent any
of this oil from getting on the brake shoe facings, which
might cause an extreme brake grab condition.
It is recommended that a suitable volatile, non-toxic,
greaseless type solvent be used to clean the oil from the
braking surface of the new brake drums before they are
•placed in service to insure the cleanest possible surface.
Gasoline or kerosene should not be used as there is
danger that a portion of the diluated oil substance may
be left on the braking surface that may later cause
difficulty.
Installation
1.
Make brake adjustment as outlined in this section.
CHEVROLET CHASSIS SERVICE MANUAL