oil level PONTIAC FIERO 1988 Service User Guide

4B-4 REAR AXLE
d. Incorrect driveline angle.
Noise changes on a different type of road.
a. Road noise.
b. Tire noise.
Noise tone lowers as car speed is lowered.
a. Tire noise.
Similar noise is produced with car standing and
driving.
a. Engine noise.
b. Transmission noise.
Vibration. a. Rough rear wheel bearing.
b. Unbalanced
or damaged propeller shaft.
c. Tire unbalance.
d. Worn
universal joint in propeller shaft.
e. Incorrect driveline angle.
f. Mis-indexed propeller shaft at pinion
flange.
g. Pinion
flange
runout too great.
A knock or click approximately every two
revolutions of the rear wheel.
a. A rear wheel bearing.
Noise most pronounced on turns.
a. Rear
axle side gear and pinion noise.
A continuous low pitch whirring or scraping
noise starting at relatively low speed.
a. Pinion bearing noise.
Drive noise, coast noise or float noise.
a. Ring and
pinion gear noise.
Clunk on acceleration or deceleration.
a. Worn rear
axle pinion shaft in case or side
gear hub counterbore in case worn oversize.
b. Insufficient
lubrication on propeller shaft
slip yoke.
c. Worn U-joints on
propeller shaft. Front or
rear.
Groan in "Forward" or "Reverse".
a. Wrong
or contaminated lube in rear axle.
b. Worn bushings.
Chatter on turns.
a. Wrong
or contaminated lube in rear axle.
b. Clutch
cone worn and/or
spring(s) worn.
Clunk or knock on rough road operation.
a. Excessive end play of axle shafts to
differential cross shaft.
b. Worn bushings.
PRE-REPAIR INVESTIGATION AND TROUBLE
DIAGNOSIS
A careful1 diagnosis of the rear axle prior to
disassembly will often reveal valuable information as to
the extent and type of repairs or adjustments necessary.
Since frequent causes of axle noises are improper
backlash, pinion bearing pre-load, or side bearing
pre-load, or a combination, a few simple adjustments
may be all that are necessary to correct a problem.
Therefore, before removing the rear axle from the
housing, the following checks should be made with the
results recorded and analyzed:
1) Backlash; 2) Total Assembly
Preload; 3) Tooth Contact Pattern Test;
4)
Fluid Level; and 5) Fluid Contamination.
Use care at all times to keep dirt and other foreign
matter, such as grinder dust, soot or sand, away from
differential to prevent possibility of subsequent failure.
The pinion and ring gear must be completely
assembled, installed and all pre-load and backlash
adjustments completed prior to the start of this method
of pinion depth setting. The following procedure can
be used in place of the gage method of pinion depth
setting.
Gear Tooth Nomenclature
The side of the ring gear tooth which curves
outward, or is convex, is referred to as the "drive" side.
The concave side is the "coast" side. The end of the
tooth nearest center of ring gear is referred to as the
"toe" end. The end of the tooth farthest away from the
center is the "heel" end. Toe end of tooth is smaller
than heel end.
It is very important that tooth contact be tested
before the rear axle carrier assembly is disassembled.
Variations in the carrier or pinion rear bearing may
cause the pinion to be too far away from, or close to,
the ring gear. Thus, the tooth contact must be tested
and corrected, if necessary, or the gears may be noisy.
Tooth Contact Pattern Test
1. Wipe oil out of carrier and carefully clean each
tooth of ring gear.
2. Use gear marking compound part number
1052351 or equivalent and apply this mixture
sparingly to all ring gear teeth, using a medium
stiff brush. When properly used, the area of
pinion tooth contact will be visible when hand
load is applied.
3. Tighten bearing cap bolts to 75
N.m (55 lb. ft.).
4. Expand
brake shoes using parking brake cables
until a torque of 54 to
70 N-m (40-50 lb. ft.) is
required to turn the pinion.
A test made without loading the gears will not
give a satisfactory pattern. Turn pinion flange
with wrench so that ring gear rotates one full
revolution, then reverse rotation so that ring gear
rotates one revolution in opposite direction.
5. Observe
pattern on ring gear teeth and compare
with Fig. 3.
Effects of Increasing Load on Teeth Contact
Pattern
When "load" on ring and pinion gear is
increased, such as when car is accelerated forward
from standstill or from normal drive, the tooth contact
will tend to spread out and, under very heavy load, will
extend from near toe to near heel on the drive side. The
entire contact also tends to shift toward heel under
increasingly heavier loads and will become somewhat
broader with respect to tops and bottoms of teeth. The
patterns obtained by this tooth contact pattern test
approximate a light load and, for this reason, they will
extend only about halfway.

4B-8 REAR AXLE
GENERAL lNFORMATlON
A universal joint connects the rear end of the
propeller shaft to a pinion flange, having a splined end
which fits over and drives the
hypoid pinion gear. The
housing is attached to the underbody through a center
bearing support. Inside the housing, an extension shaft
is splined to the drive pinion at the rear end, and to the
companion flange at the other end. Two pre-loaded
tapered roller bearings support the
hypoid pinion gear
in the carrier. The inner race of the rear bearing is a
light press fit on the pinion stem. The inner race of the
front bearing combines a light press fit to a close sliding
fit on the pinion flange end of the pinion stem. The
outer race of each bearing is pressed against a shoulder
recessed in the carrier. Tightening the pinion nut
compresses a collapsible spacer which bears against the
inner race of the front bearing and a shoulder on the
pinion stem. This spacer is used to enable accurate
bearing pre-load adjustment and
maintain a pre-load
on both front and rear pinion bearings. Adjustment of the
fore and aft position of the pinion is obtained by
placing
shims between the head of the drive pinion and
the rear pinion bearing.
The rear axle case is of
one-piece construction and is supported in the carrier
by two tapered roller side bearings. These are
pre-loaded by inserting
shims between the bearings and
the carrier. The rear axle case assembly is positioned
for proper ring gear to pinion backlash by varying the
shin1 thickness from side to side. The ring gear is bolted
to the case. Two side gears have splined bores for
driving the axle shafts. They are positioned to turn in
counterbored cavities in the case. The two rear axle
pinions have
smooth bores and are held in position by
a solid pinion cross shaft, mounted and locked in the
rear axle case. All four gears are in
mesh with each
other and because the pinion gears turn freely
on their
shaft, they act as idler gears when the rear wheels are
turning at different speeds. The pinions and side gears
are backed by steel thrust washers.
LIMITED-SLIP REAR AXLE
The operation of the Limited-Slip differential is
the same as the standard differential, except that there
is additional friction provided by the clutches or cones.
Under ordinary driving and cornering conditions, the
clutches or cones slip, allowing the outside wheel to
turn faster than the inner. Under poor traction
conditions, such as ice, snow, or loose gravel under one
driving wheel, the increased friction provided by the clutches
or cones increases the driving torque available
to the wheel with the better traction. The clutches or
cones are spring loaded to provide the increased
driving torque under extremely low traction
conditions.
Most rear axle service repairs can be made with
the rear axle assembly in the car, by raising the rear end
of the car with the rear axle hanging
on the shock
absorbers.
ON-VEHICLE SERVICE
CARRIER COVER AND GASKET
Remove or Disconnect
1. Having a container in place, remove cover bolts
and pry cover loose to drain lubricant.
2. Make sure both gasket sealing surfaces are clean.
Install or Connect
Use sealant
1052366 or cover gasket
only.
1. Torque cover bolts in a crosswise pattern to
insure uniform draw on gasket. Torque
27 N.m
(20 Ib.fr.).
2. Fill with lubricant to a level within 4.5mm (3116")
or filler plug hole. Refer to specifications for correct
lubricant usage and quantity.
Axle Shaft
a Remove or Disconnect
1. Raise car and remove wheel and brake drum.
2. Clean all dirt from area of carrier.
3. Remove bolts and differential carrier cover and
allow lubricant to drain.
4. Remove pinion shaft lock screw and pinion shaft.
1 -PINION SHAFT 2-PINION SHAFT 1
SCREW 520122 48
Fig. 401 Pinion Shaft Lock Bolt
5. Push flanged end of axlc shalt inward to pcrmil
removal of "C" locks, thcn rcmovc axlc shafts
being
careful not to cl;uii~~gc oil scal (Fig. 402).
6. Remove axlc shaft from housing, bcing curcl'ul not
to
damage oil scal.

REAR AXLE 48-9
lnstall or Connect
1. Slide axle shaft into place taking care that splines
on end of shaft do not damage oil seal and that
they engage with splines of rear axle side gear.
2. Install
axle shaft
"C" lock on bottom end of axle
shaft and push shaft outward so that shaft lock
seats in counterbore of rear axle side gear.
3. Position
rear axle pinion shaft through case and
pinions, aligning hole in shaft with lock screw
hole. Install lock screw and torque to 27
N-m (20
1b.ft.l
4. using a new gasket, install carrier cover and
torque
bolts to 27 N-m (20 1b.ft.). Fig. 403 Axle Shaft Bearing and Seal Remover
5. Fill
axle with lubricant to a level within 9.5mm
(3/8") of filler hole. See specifications for proper
lubricant.
6. Install brake drum and wheel.
7. Lower
car and test operation of axle.
Fig. 402 Axle Shaft "C" Locks
Oil Seal and/or Bearing (With Axle Shaft
Removed)
Remove or Disconnect
1. Remove seal
from housing with a pry bar behind
steel case of seal, being careful not to damage
housing.
1 --BEARING 2- DRIVE HANDLE J-8092
3-AXLE SHAFT BEARING INSTALLER J-23765
5201 25-48
Fig. 404 Axle Shaft Bearing Installer
Fig.
405 Installing Axle Shaft Seal
Pinion Oil Seal
Remove or Disconnect
I
2.
Install axle shaft bearing remover J 22813-01 and 1. Mark the drive shaft and pinion flange so they I
remove bearing and seal. See Fig. 403. can
be reassembled in the same position. I
Install or Connect
1. Lubricate new bearing with gear lubricant and in-
stall bearing so that tool bottoms against shoulder in
housing, using tools
5-23765 and 5-8092. See Fig.
404.
2. Lubricate new seal lips with gear lubricant. Position
seal on tool and position
seal into housing bore.
Tap seal into place so that it is flush with axle tube
Fig. 405. 2.
With rear
wheels off floor, turn rear wheels and
tap brake backing plates with a soft hammer to
ensure that brakes are free.
3. Mark
the position of the pinion flange, pinion
shaft and nut so the proper pinion bearing
pre-load can be maintained.
4. Remove pinion flange nut and washer.
5. With suitable container in place to hold fluid,
remove pinion flange.

BRAKES 5-3
DIAGNOSIS AND INSPECTION
BRAKE SYSTEM TESTING
(Figures
2 through 4)
Brakes should be tested on dry, clean, reasonably
smooth and level roadway. A true test of brake performance
cannot be made if the roadway is wet, greasy or covered
with loose dirt so that all tires do not grip the road equally.
Testing will also be affected if the roadway is crowned
which would throw the weight of the car toward the wheels
on one side. If the roadway is too rough, the wheels will tend
to bounce. Test brakes at different car speeds with both light and
heavy pedal pressure, avoid locking the brakes and sliding
the tires. Locked brakes and sliding tires do not indicate
brake efficiency, because heavily braked, but turning
wheels will stop the car in less distance than locked brakes.
More tire-to-road friction is present with a heavily braked
turning tire than with a sliding tire. The brake system is designed and balanced to avoid
locking the wheels, except at very high deceleration levels.
The shortest stopping distance and best control is achieved
without brake lock-up.
Because of high deceleration capability, a firmer pedal
may be felt at higher deceleration levels.
External Conditions That Affect Brake Performance
1. Tires. Tires having unequal contact and grip on road
will cause unequal braking. Tires must be equally
inflated and tread pattern of right and left tires must
be approximately equal.
2. Car Loading. A heavily loaded car requires more
braking effort. When a car has unequal loading, the
most heavily loaded wheels require more braking
power than others.
3. Wheel Alignment. Misalignment of the wheels, par-
ticularly excessive camber and caster, will cause the
brakes to pull to one side.
4. Front Wheel Bearings. A loose front wheel bearing
BRAKE FLUID LEAKS
With engine running at idle and the transmission in neu-
tral, depress the brake pedal and hold a constant foot pres-
sure.
If the pedal gradually falls away with the constant
pressure, the hydraulic system may be leaking. Perform a
visual check to confirm any suspected leak.
Check the master cylinder fluid levels. While a slight drop
in reservoir level does result from normal lining wear, an
abnormally low level in either reservoir indicates
a leak in
the system. The hydraulic system may be leaking either
internally or externally. See "Master Cylinder Check."
Also, the system may appear to pass this test but still have
slight leakage.
If fluid levels are normal, check the vacuum booster
pushrod length. If an incorrect length pushrod is found,
adjust or replace the
pushrod. Check the service brake
pedal travel and the parking brake adjustment.
When checking the fluid levels, the master cylinder reser-
voir may be as low as
25 mm (1 inch) from the top if the front
linings are worn. This is not abnormal.
MASTER CYLINDER CHECK
These checks will help locate some master cylinder mal-
functions. Use the Brake Diagnosis Charts to help isolate
the problem if it is not found by using these tests.
1. Check for a cracked master cylinder casting or brake
fluid around the master cylinder. Leaks are indicated
only if there is at least a drop of fluid. A damp condi-
tion is not abnormal.
2. Check for a binding pedal linkage.
3. Disassemble the master cylinder and check for swol-
len or stretched piston
seal(s). If swollen seals are
found, substandard or contaminated brake fluid
should be suspected.
If contaminated, all compo-
nents should be disassembled and cleaned. All rub-
ber components should be replaced and all the pipes
should be flushed.
permits the front wheel to tilt and lose contact with the
SUBSTANDARD OR CONTAMINATED brake shoe linings causing erratic brake operation. BRAKE FLUID
WARNING LAMP OPERATION
The brake system uses a single red "BRAKE" warning
lamp located in the instrument panel cluster. When the
ignition switch is in the "START" position, the "BRAKE"
warning lamp should come on. It should go off when the
ignition switch returns to the "RUN" position.
The following conditions will activate the "BRAKE"
warning lamp:
1. Parking brake applied. The lamp should be on when
tfie parking brake is applied and the ignition switch is
"ON."
2. Pressure differential switch detects a failure. See
"Brake Pressure Differential Warning Switch" in this
section. Improper
brake fluid, mineral oil or water in the fluid may
cause the brake fluid to boil or the rubber components to
deteriorate.
If piston cups are swollen, the rubber parts have dete-
riorated. This deterioration may also be seen by swollen
wheel cylinder piston cups on the drum brake wheels or a
swollen master cylinder cover diaphragm.
If rubber deterioration is evident, disassemble all hydrau-
lic parts and wash with alcohol. Dry these parts with com-
pressed air before assembly to keep alcohol out of the
system. Replace all rubber parts in the system, including
hoses. Check for fluid on the linings. If excessive fluid is
found, replace the linings.
If master cylinder piston seals are satisfactory, check for
leakage or excessive heat conditions. If condition is not
found, drain fluid, flush with brake fluid, fill and bleed the
system.

BRAKES 5-7
ONmCAR SERVICE
BRAKE PEDAL REPLACEMENT
See Figure 5.
STOPLAMP SWITCH ADJUSTMENT
Adjust (Figure 6)
With brake pedal in fully released position, the stop-
lamp switch plunger should be fully depressed
against the brake pedal shank. Adjust switch by mov-
ing in or out as necessary.
1. Make certain that the tubular clip is in brake pedal
mounting bracket.
2. With brake pedal depressed, insert switch into tubu-
lar clip until switch body seats on clip. Clicks can be
heard as the threaded portion of the switch is pushed
through the clip toward the brake pedal.
3. Pull brake pedal fully rearward against brake pedal
stop until clicking sounds can no longer be heard.
Switch will be moved in tubular clip providing adjust-
ment.
4. Release brake pedal and then repeat step 3, to
assure that no clicking sounds remain.
FILLING MASTER CYLINDER RESERVOIRS
The master cylinder must be kept properly filled to insure
adequate reserve and to prevent air from entering the hydraulic
system. However, because of expansion due to
heat absorbed from brakes and from engine, master cylin-
der must not be overfilled.
The brake fluid reservoir is on the master cylinder which
is located under the hood on the left side of the vehicle.
Thoroughly clean reservoir cover before removal to avoid
getting dirt into reservoir. Remove cover and diaphragm.
NOTICE: Do not use fluid which contains a petro-
leum base. Do not use a container which has been
used for petroleum based fluids or a container which
is wet with water. Petroleum based fluids will cause
swelling and distortion of rubber parts in the hydrau-
lic brake system and water will mix with brake fluid,
lowering the fluid boiling point. Keep all fluid con-
tainers capped to prevent contamination.
Add fluid as required to bring level to
approximately6mm
(114-inch) from top of reservoir. Use Delco Supreme No. 1 1
Hydraulic Brake Fluid or equivalent. Fluid must be "DOT
3."
BLEEDING BRAKE HYDRAULIC SYSTEM
A bleeding operation is necessary to remove air when it is
introduced into the hydraulic system. It may be necessary to bleed the hydraulic system at all
four brakes if air has been introduced through a low fluid
level or by disconnecting brake pipes at master cylinder. If a
Figure
5 Brake Pedal Mounting

5A3-2 COMPOSlf E MASTER CYLINDER
GENERAL DESCRIPTION
This master cylinder is a composite design
(plastic reservoir and aluminum bore) incorporating
a
conventional front to rear brake system split. The
primary piston provides the fluid pressure to the front
brakes, while the secondary piston provides the fluid
pressure to the rear brakes. If pressure is lost from
either system, the remaining system will function to
stop the vehicle.
A quick take-up feature is incorporated which
provides a large volume of fluid to the wheel brakes at
low pressure with initial brake apply. The low pressure
fluid quickly provides the displacement requirements
created by the seal retraction of the pistons into the
front calipers.
Important
e Replace all components included in repair kits
used to service this master cylinder.
e Lubricate rubber parts with clean brake fluid to
ease assembly.
a Do not use lubricated shop air on brake parts as
damage to rubber components may result.
e If any hydraulic component is removed or
disconnected, it may be necessary to bleed all or
part of the brake system.
e The torque values specified are for dry,
unlubricated fasteners.
a Perform service operations on a clean bench free
from all mineral oil materials.
ON-CAR SERVICE
MASTER CYLINDER ASSEMBLY
Remove or Disconnect (Figure 5,432)
1.
Tube nuts (14) and hydraulic lines.
e Plug open lines to prevent fluid loss and
contamination.
2. Two attaching nuts (15).
3. Master cylinder (13).
s See NOTICE on page 5-1.
Install or Connect (Figure 5A3-2)
1.
Master cylinder (13) with attaching nuts (15) to
27
N-m (20 lb-ft).
2. Hydraulic lines and tube nuts
(14) to 23 7%-m (17
lb-ft).
3. Fill master cylinder to proper level with clean
brake fluid.
e Bleed hydraulic system.
13. MASTER CYLINDER I ASSEMBLY
Figure 5A3-2 Removing Master Cylinder Assembly
MASTER CYLINDER OVERHAUL
+++ Disassemble (Figure 5A3-1) [I]
Important
Reservoir cover and diaphragm can be
inspected and/or serviced without
removing the master cylinder from the
vehicle.
1. Master cylinder (13) completely from vehicle as
previously described.
2. Reservoir cover (1) and diaphragm (2).
e Wipe reservoir cover clean before removing.
e Empty fluid from reservoir (only if master
cylinder is to be completely removed and
overhauled).
Inspect
s Reservoir cover (I) and diaphragm (2) for:
s Cuts
o Cracks
e Nicks
e Deformation
e Replace damaged parts.
3. Retainer
(5) while depressing primary piston
assembly (6).
e Take care not to damage the piston, bore, or
retainer groove.
4. Apply low pressure dry compressed air into
outlet port at blind end of bore (other outlet port
plugged) to remove:
@ Primary piston assembly (6).
s Secondary piston (10).
s Spring (1 1).
e Spring retainer (8).
5. From secondary piston (10):
e Seals (7 and 9).
Recheck fluid level. e Spring retainer (8).

ENGINE GENERAL INFORMATION 6-3
B, Section 6E2 - Fuel Injection (TBI)
B, Section 6E3 - Fuel Injection (Ported)
ENGINE MECHANICAL DIAGNOSIS
The following diagnostic information covers common problems and possible causes. When
the proper diagnosis is made, the problem should be corrected by adjustment, repair or part
replacement as required. Refer to the appropriate section of the manual for these procedures.
EXCESSIVE OIL LOSS
B, External oil leaks. Tighten bolts and/or replace o Continuous high speed driving, and/or severe
gaskets and seals as necessary. usage
such as trailer hauling, will normally cause
decreased oil mileage.
e Improper reading of dipstick. Check oil with car PCV system malfunctioning. on a level surface and allow adequate drain-down Valve guides and/or valve stem seals worn, or time.
seals omitted. Ream guides and install oversize
service valves and/or new valve stem seals.
Improper Use S.A'E' Piston rings broken, worn, or not seateded. Allow viscosity for prevailing temperatures. See
adequate time for rings to seat. Replace broken
Owner's Manual for proper specifications.
or worn rings, as necessary.
Piston improperly installed or misfitted.
LOW OIL PRESSURE
Slow idle speed. Set idle speed to correct
specification, if not ECM controlled.
Incorrect, or malfunctioning, oil pressure switch.
Incorrect, or malfunctioning, oil pressure gage.
Replace with proper gage.
.*
Improper oil viscosity, or diluted oil. install oil of
proper viscosity for expected temperature, or
install new oil if diluted with moisture or
unburned fuel mixtures.
o Oil pump worn or dirty.
e Plugged oil filter.
e Oil pickup screen loose or plugged.
B, Hole in oil pickup tube.
e Excessive bearing clearance. Replace if necessary.
o Cracked, porous or plugged oil galleys. Repair or
replace block.
o Galley plugs missing or misinstalled. Install
plugs, or repair as necessary.
VALVE TRAIN NOISE
e Low oil pressure. Repair as necessary. (See o Broken valve spring.
preceding diagnosis for low oil pressure.)
o Sticking valves.
o Loose rocker arm attachments. Inspect and B, Lifters worn, dirty, or defective. Clean, inspect,
test and replace as necessary.
repair as necessary.
o Camshaft worn, or poor machining. Replace
o Worn rocker arm and/or pushrod. camshaft.
B, Worn valve guides.
ENGINE KNOCK DIAGNOSIS
KNOCKS COLD AND CONTINUES FOR TWO TO THREE MINUTES
INCREASES
WITH TORQUE
o Vacuum operated EFE engines may have valve o Excessive piston to bore clearance. Replace
knock. Replace EFE valve. piston.
e Flywheel contacting splash shield. Reposition
splash shield.
e Loose or broken balancer or drive pulleys.
Tighten, or replace as necessary. Cold engine piston knock usually
disappears when the cylinder is grounded
out. Cold engine piston knock which
disappears in 1.5 minutes should be
considered acceptable.

2.8 LITER V-6 6A2-9
INTAKE MANIFOLD (FIGURE 6A2-7)
Removal
Disconnect battery.
Remove air cleaner.
Drain coolant.
Refer to Section 6E3 for removal of the following
PFI sub-assemblies.
e Plenum
e Fuel Rail
e Runner
Disconnect spark plug wires at spark plugs.
Disconnect wires at coil.
Remove distributor cap and spark plug wires.
Mark distributor position and remove hold down
bracket.
Remove distributor.
Remove air management hose, manual
transmission only.
Disconnect emission canister hoses. Remove pipe
bracket (front left valve cover).
Remove left valve cover.
Remove air management bracket, manual
transmission only.
Remove right valve cover.
Remove upper radiator hose.
Disconnect heater hose.
Disconnect coolant switches.
Remove manifold bolts.
Remove manifold. Discard manifold gaskets and
remove loose RTV from front and rear ridges of
cylinder case.
Installation
When installing intake gaskets, notice that the
gaskets are marked Right Side and Left Side
(carbureted only). Use them only as indicated to
maintain designed efficiency of this engine.
1. Make
sure that no oil or water is present on
surface when new RTV is applied. Place a 5mm
diameter
(3/16") bead of RTV, # 1052917 or
equivalent, on each ridge.
2. Install
new intake gaskets on cylinder heads.
Hold in place by extending ridge RTV bead up
6mm onto the gasket ends. The new intake
gaskets will have to be cut, where indicated, to
install behind push rods. Cut only those areas
that are necessary.
3. Install intake
manifold on engine. Make sure
areas between case ridges and intake are
completely sealed.
4. Install manifold retaining bolts and nuts and
torque in the sequence shown in Figure 6A2-7.
5. Install heater and radiator hose to manifold.
6. Install rocker covers as previously outlined.
7. Connect coolant switches.
8. Install air management bracket.
9. Install pipe bracket (front left rocker cover).
10. Install distributor, distributor cap and retaining
nut. Do not tighten.
11. Refer to Section 6E3 for installation of PFI
sub-assemblies removed. 12.
Connect
necessary wires and hoses.
13. Fill cooling system with
the proper mixture of
ethylene glycol anti-freeze and water. Do not
install radiator cap.
14. Start
engine, set intitial timing. After set, torque
distibutor hold down clamp bolt to 34
N-m (25
lb. ft.). Recheck timing after torquing bolt.
15. Let engine
run until radiator upper hose becomes
hot (thermostat open).
16. With
engine idling, add coolant to radiator, if
necessary, until level reaches bottom of filler
neck.
17. Install
radiator cap, making sure arrows on cap
line up with overflow tube.
Figure 6A2-8 Exhaust Manifold
EXHAUST MANIFOLD (FIGURE 6A2-8)
Removal (Left)
1. Disconnect battery.
2. Raise vehicle.
3. Disconnect exhaust pipe.
4. Remove
(4) rear manifold bolts and (1) nut.
5. Lower vehicle.
6. Disconnect air management, hoses and wires.
7. Remove power steering and fuel line bracket.
8. Remove manifold.
Installation (Left)
1. Clean mating surfaces on manifold and head,
then install manifold in position and install bolts.
2. Torque
manifold bolts to 34
N.m (25 ft. lbs.).
3. Install power steering bracket.
4. Raise vehicle.
5. Install exhaust pipe.
6. Lower vehicle.
7. Connect battery.
Removal (Right)
1. Disconnect battery.
2. Raise vehicle.
3. Disconnect exhaust pipe.
4. Lower vehicle.

2.8 LITER V.6 6A2-15
18-30 N.m (13-22 FT. LBS.)
I 11 47-48 N.m (20-35 FT. LBS.) I
Figure 6A2-17 Water Pump/Front Cover Orientation
CRANKCASE FRONT COVER
Removal
1. Raise engine.
2. Remove oil pan.
3. Lower vehicle.
4. Remove water pump as outlined in Section 6B.
5. If A/C equipped, remove compressor from
mounting bracket and lay aside. Then remove
compressor mounting bracket.
6. Remove torsional damper as previously outlined.
7. Disconnect lower radiator hose at front cover and
heater hose at water pump.
8. Remove remaining front cover bolts and remove
cover.
Installation
1. Install new gasket. When installing new gasket,
be sure sealing surfaces are clean. Care should be
taken not to damage sealing surfaces.
2. Place front cover on the engine, install stud bolt
and bolts, install water pump as outlined in
Section 6B, install retaining bolts and nut and
torque to specifications.
3. Connect lower radiator hose to front cover.
Torque clamps to
3.5 N-m (30 lb. in.).
4. Install torsional damper as previously outlined.
5. Install water pump as outlined in Section 6B.
6. If A/C equipped, install compressor mounting
bracket and install compressor.
7. Raise vehicle.
8. Inspect oil pan gasket replace if necessary.
9. Install oil pan.
10. Lower vehicle.
11. Install serpentine belt.
12. Fill cooling system. Leave radiator cap off.
13. Connect battery negative cable and start engine.
14. Run engine until upper radiator hose becomes
hot (thermostat open).
15. Check coolant level and add as necessary.
16. Install radiator cap, making sure arrows on cap
line up with overflow tube.
OIL SEAL (FRONT COVER)
Replacement
With Cover Removed
1. With cover removed, pry oil seal out of cover
from the front with a large screw driver.
2. Install new seal so that open end of the seal is
toward the inside of cover and drive it into
position with Tool
5-23042. Support cover at seal
area. Pre-lube seal with engine oil prior to
installation of torsional damper.
With Cover Installed
1. With torsional damper removed, pry seal out of
cover from the front with a large screw driver,
being careful not to damage the surface on the
crankshaft.
2. Install new seal so that open end of seal is toward
the inside of cover and drive it into position with
To01 5-23042.
Figure 6A2-18 Timing Chain and Sprockets
TIMING CHAIN AND SPROCKET
Removal
1. Remove crankcase front cover as previously
outlined.
2. Place #1 piston at top dead center with the
marks on the camshaft and crankshaft sprockets
aligned (#4 firing).
3. Remove camshaft sprocket bolts and remove
camshaft sprocket and chain (Figure
6A2- 18).
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.
Installation
1. Install timing chain on camshaft sprocket, lube
thrust surface with Molykote or its equivalent.
Hold the sprocket vertically with the chain
hanging down and align the marks on the
camshaft and crankshaft sprockets. (Refer to
Figure
6A2- 19).

6A3-2 V-8 ENGINE
VALVE TRAIN
A very simple ball pivot-type train is used.
Motion is transmitted from the camshaft through the
hydraulic lifter and push rod to the rocker arm. The
rocker arm pivots on its ball and transmits the
camshaft motion to the valve. The rocker-arm ball is
retained by a nut.
HYDRAULIC VALVE LIFTERS
Hydraulic Valve Lifters are used to keep all parts
of the valve train in constant contact.
The hydraulic lifter assembly consists of: a roller,
the lifter body, which rides in the cylinder block boss,
a plunger, a push rod seat, a metering valve, a plunger
spring, a check ball and spring, a check ball retainer
and a push rod seat retainer.
When the lifter is riding on the low point of the
cam, the plunger spring keeps the plunger and push rod
seat in contact with the push rod.
When the lifter body begins to ride up the cam
lobe, the check ball cuts off the transfer of oil from the
reservoir below the plunger. The plunger and lifter
body then rise as a unit, pushing up the push rod and
opening the valve.
As the lifter body rides down the other side of the
cam, the plunger follows with it until the valve closes.
The lifter body continues to follow the cam to its low
point, but the plunger spring keeps the plunger in
contact with the push rod. The ball check valve will then
move off its seat and the lifter reservoir will
remain full.
INTAKE MANIFOLD
The intake manifold for those engines with
carburetors are made of cast iron or aluminum double
level design for efficient fuel distribution. An Exhaust
Gas Recirculation (EGR) port is also cast into the
manifold for the mixture of exhaust gases with the fuel
air mixture.
The intake manifold for those vehicles equipped
with
PFI is a cast aluminum unit. It centrally supports
a fuel rail with
8 fuel injectors.
EXHAUST MANIFOLDS
Two cast iron exhaust manifolds are used to
direct exhaust gases from the combustion chambers to
the exhaust system. The left hand side manifold
receives a heat shield that is used to route heated air
to the air cleaner. for better fuel vaporization during
warm-up.
COMBUSTION CHAMBERS
Combustion Chambers are cast to insure uniform
shape for all cylinders. Spark plugs are located between
the intake and exhaust valves. The contoured wedge
shape of the combustion chamber minimizes the
possibility of detonation, facilitates breathing and
provides swirling turbulence for smooth, complete
combustion.
ENGINE LUBRICATION
Full pressure lubrication through a full flow oil through drilled passages, to the camshaft and
filter, is furnished by a gear-type oil pump. The crankshaft to lubricate the bearings. The valve lifter oil
distributor, driven by a helical gear on the camshaft,
gallery feeds the valve lifters which, through hollow
drives the oil pump. The main oil gallery feeds oil,
push rods, feed the individually mounted rocker arms.