1993 CHEVROLET DYNASTY engine

CLUTCH DISC REPLACEMENT
REMOVAL
(1) Remove transaxle. See Group 21, Manual Tran-
saxle, for procedure. (2) Mark clutch cover and flywheel, to maintain
their same relative positions when installing clutch
assembly (Fig. 4). (3) Insert Clutch Disc Aligning Tool C-4676
through the clutch disc hub to prevent the clutch disc
from falling and damaging the facings (Fig. 5). (4) Loosen clutch cover attaching bolts, one or two
turns at a time, in a crisscross pattern, to release
spring pressure evenly and avoid cover damage.
CAUTION: Do not touch the clutch disc facing with
oily or dirty hands. Oil or dirt transferred from your
hands onto the clutch disc facing may cause clutch
chatter.
(5) Remove the clutch pressure plate and cover as-
sembly and disc from flywheel. Handle carefully to
avoid contaminating the friction surfaces.
INSPECTION
(1) Inspect for oil leakage through engine rear
main bearing oil seal and transaxle input shaft seal.
If leakage is noted, it should be corrected at this
time. (2) The friction faces of the flywheel and pressure
plate should not have excessive discoloration, burned
areas, small cracks, deep grooves, or ridges. Replace
parts as required.
CAUTION: Do not polish flywheel to a ``mirror like''
surface.
Fig. 4 Manual Transaxle Clutch
Fig. 5 Clutch Disc Aligning Tool
Ä MANUAL TRANSAXLE CLUTCH 6 - 5

(3) Clean the flywheel face with medium sandpa-
per (80-160 grade), then wipe the surface with min-
eral spirits. If the surface is severely scored, heat
checked, or warped, replace the flywheel.
CAUTION: Do not flat-machine the flywheel face.
The surface profile is tapered.
(4) The heavy side of the flywheel is indicated by a
daub of white paint near the outside diameter. To
minimize the effects of flywheel unbalance, perform
the following installation procedure: (a) Loose assemble the flywheel to the crank-
shaft. Use new flywheel attaching bolts which have
sealant on the threads. If new bolts are not avail-
able, apply Loctite sealant to the threads of the
original bolts. This sealant is required to prevent
engine oil leakage. (b) Rotate the flywheel and crankshaft until the
daub of white paint (heavy side) is at the 12 o'clock
position. (c) Torque flywheel attaching bolts to 95 N Im(70
ft. lbs.). Use a crisscross pattern when tightening
bolts.
(5) The disc assembly should be handled without
touching the facings. Replace disc if the facings show
evidence of grease or oil soakage, or wear to within
less than .38 mm (.015 inch) of the rivet heads. The
splines on the disc hub and transaxle input shaft
should be a snug fit without signs of excessive wear.
Metallic portions of disc assembly should be dry and
clean, and not been discolored from excessive heat.
Each of the arched springs between the facings
should not be broken and all rivets should be tight. (6) Wipe the friction surface of the pressure plate
with mineral spirits. (7) Using a straight edge, check clutch cover (pres-
sure plate) for flatness. The clutch cover (pressure
plate) friction area should be slightly concave, with
the inner diameter 0.02 mm to 0.1 mm (.0008 in. to
.0039 in.) below the outer diameter. It should also be
free from discoloration, burned areas, cracks,
grooves, or ridges. (8) Using a surface plate, test cover for flatness.
All sections around attaching bolt holes should be in
contact with surface plate within .015 inch. (9) The cover should be a snug fit on flywheel dow-
els. If the clutch assembly does not meet these re-
quirements, it should be replaced.
INSTALLATION
(1) Mount clutch assembly on flywheel,being care-
ful to properly align dowels and the alignment marks
made before removal. The flywheel side of the clutch
disc is marked for proper installation. If new clutch
or flywheel is installed, align cover balance spot as
close as possible to flywheel balance orange spot. Ap-
ply pressure to the alignment tool. Center the tip of the tool into the crankshaft and the sliding cone into
the clutch fingers. Tighten the clutch attaching bolts
sufficiently to hold the disc in position. (2) To avoid distortion of the clutch cover, bolts
should be tightened a few turns at a time, in a criss-
cross pattern, until they are all seated. Tighten bolts
to 28 N Im (250 in. lbs.) following a crisscross pattern
sequence. Remove clutch disc alignment tool. (3) Install transaxle. See group 21, Manual Tran-
saxle, for procedures.
RELEASE BEARING AND FORK
Remove the transaxle from the vehicle. See group
21 for removal and installation procedures.
REMOVAL AND INSTALLATION
(1) Remove clutch release shaft E-clip.
(2) Remove the clutch release shaft and then slide
the fork and bearing assembly off the bearing pilot. (3) Remove the fork from the bearing thrust plate.
(4) Examine the condition of the bearing. It is pre-
lubricated and sealed and should not be im-
mersed in oil or solvent. (5) The bearing should turn smoothly when held in
the hand under a light thrust load. A light drag
caused by the lubricant fill is normal. If the bearing
is noisy, rough, or dry, replace the complete bearing
assembly with a new bearing. (6) The bearing has a plastic sleeve pre-lubricated
at assembly. Wipe out the old grease. Refill the
sleeve cavities and coat the inner surface with mul-
tipurpose grease. If the liner is cracked or worn, re-
place the bearing assembly. (7) Check the condition of the spring clips. If the
clips are broken or distorted, replace the bearing as-
sembly. (8) Before assembling the fork, lubricate the
rounded thrust pads and the spring clip cavities with
multipurpose grease. (9) Assemble the fork to the bearing by sliding the
thrust pads under the spring clips. Be careful to
avoid distorting the spring clips. These clips prevent
the bearing thrust plate from rotating with the bear-
ing. (10) Slide the bearing and fork assembly onto the
input shaft bearing retainer. (11) Position the release shaft bushings in the
housing and install the release shaft. A small
amount of bearing grease between the release shaft
bushing and the shaft is beneficial but not required.
Install the retainer clip in the shaft groove near the
large bushing. (12) Install the release lever and retaining clip on
the outer end of the release shaft.
CLEANING PRECAUTIONS
Condensation from steam vapors tend to accumu-
late on the internal clutch mechanism when the ve-
6 - 6 MANUAL TRANSAXLE CLUTCH Ä

COOLING SYSTEM
CONTENTS
page page
ACCESSORY DRIVE BELTS ............... 24
ENGINE BLOCK HEATER ................. 28
GENERAL INFORMATION .................. 1 SERVICE PROCEDURES
.................. 10
SPECIFICATIONS ....................... 29
GENERAL INFORMATION
Throughout this group, references may be made to
a particular vehicle by letter or number designation.
A chart showing the breakdown of these designations
is included in the Introduction Section at the front of
this service manual.
COOLING SYSTEM
The cooling system consists of an engine cooling
module, thermostat, coolant, a water pump to circu-
late the coolant. The engine cooling module may con-
sist of a radiator, electric fan motor, shroud, radiator
pressure cap, coolant reserve system, transmission oil
cooler, hoses, clamps, air condition condenser, trans-
mission oil lines and charge air cooler.
² When Engine is cold: Thermostat is closed, cooling
system has no flow through the radiator. The coolant
bypass flows through the engine only. ²
When Engine is warm: Thermostat is open, cooling
system has bypass flow and coolant flow through ra-
diator. Its primary purpose is to maintain engine temper-
ature in a range that will provide satisfactory engine
performance and emission levels under all expected
driving conditions. It also provides hot water (cool-
ant) for heater performance and cooling for auto-
matic transmission oil. It does this by transferring
heat from engine metal to coolant, moving this
heated coolant to the radiator, and then transferring
this heat to the ambient air. Coolant flow circuits for 2.2L and 2.5L engine
equipped vehicles are shown in (Fig 1). Turbocharged
equipped engines coolant routing and plumbing are
shown in (Fig 2). The 3.0L engine coolant routing is
shown in (Fig 3). The 3.3L and 3.8L engine coolant
routing is shown in (Fig 5).
Fig. 1 Cooling System OperationÐ2.2/2.5L Engines
Ä COOLING SYSTEM 7 - 1

TURBOCHARGER COOLANT ROUTING
Engines equipped with a Turbocharger maintain a
continuous engine coolant flow through the Turbo-
charger bearing housing water jacket. Hose and tube
assemblies provide a closed loop coolant flow from
the cylinder block water jacket to the turbocharger
housing and back to the cylinder head waterbox (Fig.
2). Excluding heated intake manifold hose routing
(hose is routed from waterbox directly to heater), all
other system functions are essentially the same as
shown for standard engines. During any reassembly procedures all pipe fittings
in water jacket, bearing housing and waterbox re-
quire cleaning and application of thread sealant for
entire length of threads. Tighten all fittings to
torque specified in (Fig 2).
WATER PIPESÐ3.0L
The 3.0L engines use metal piping beyond the
lower radiator hose to route coolant to the suction
side of water pump, located in the V of the cylinder
banks. These pipes are also provided with inlet nipples for
thermostat bypass and heater return coolant hos-
es,and brackets for rigid engine attachment. The
pipes employ O-rings for sealing at their interconnec-
tion and to the water pump (Fig. 4).
Fig. 2 Turbocharger-Tube Hose AssembliesÐTurbo III Engine
Fig. 3 Cooling System OperationÐ3.0L Engine
7 - 2 COOLING SYSTEM Ä

Fig. 4 Engine Inlet Coolant Pipes
Fig. 5 Cooling System OperationÐ3.3/3.8L Engines
Ä COOLING SYSTEM 7 - 3

SERVICE PROCEDURES INDEX
page page
Automatic Transmission Oil Coolers .......... 23
Coolant ................................ 14
Coolant Recovery System (CRS) ............. 17
Cooling System Drain, Clean, Flush and Refill . . 15
Electric Fan Motor ........................ 22
Engine Thermostats ....................... 13
Fan Shroud ............................. 23 Fans
.................................. 21
Radiator Hoses .......................... 21
Radiator Pressure Cap .................... 18
Radiators ............................... 18
Testing System for Leaks .................. 17
Water Pumps ........................... 10
WATER PUMPS
A quick test to tell whether or not the pump is
working is to see if the heater warms properly. A
defective pump will not be able to circulate heated
coolant through the long heater hose. The water pump on all models can be replaced
without discharging the air conditioning system.
WATER PUMPÐ2.2/2.5L ENGINE
The 2.2/2.5L engine water pump has a diecast alu-
minum body and housing with a stamped steel impel-
ler. The 2.2/2.5L pump uses an O-ring gasket between
body and housing. The assembly bolts directly to the
block. Cylinder block to water pump sealing is provided
by a rubber O-ring.
REMOVAL (1) Drain cooling system. Refer to Draining Cooling
System in this group. (2) If equipped with air conditioning, see Solid
Mount Accessory Bracket in (Standard Service Proce-
dures) Group 9, Engine: (a) Remove air conditioning compressor and gen-
erator from solid mount bracket and set aside.It is
not necessary to discharge the a/c system. (b) Remove solid mount bracket.
(3) If the vehicle is not equipped with air condi-
tioning, remove generator and mounting bracket. (4) Disconnect lower radiator and heater hoses
from pump. (5) Remove water pump attaching screws to engine
(Fig. 1). Turbo III has a spacer between the water
pump and block on the lower screw.
DISASSEMBLY (1) Remove three screws holding pulley to water
pump. (2) Remove nine screws holding water pump body
to housing. Remove the pump body from housing
(Fig. 2). (3) Clean gasket surfaces on water pump housing
and engine block. (4) Remove and discard O-ring gaskets and clean
O-ring grooves.
Fig. 2 Water Pump ComponentsÐ2.2/2.5L
Fig. 1 Water PumpÐ2.2/2.5L Engines
7 - 10 COOLING SYSTEM Ä

INSPECTION Replace water pump body assembly if it has any of
these defects: (1) Cracks or damage on the body.
(2) Water leaks from the shaft seal, evident by
coolant traces below the vent hole. (3) Loose or rough turning bearing.
(4) Impeller rubs either the pump body or the hous-
ing.
ASSEMBLY
Body assembly and housing are serviced as separate
components. (1) Install new O-ring gasket in body O-ring groove.
(2) Assemble pump body to housing and tighten nine
screws to 12 N Im (105 in. lbs.) (Fig. 2).
(3) Rotate pump by hand to check for freedom of
movement. (4) Position water pump pulley to water pump.In-
stall three screws and tighten to 30 N Im (250 in. lbs.).
(5) Position new O-ring in housing to block O-ring
groove.
INSTALLATION (1) On Turbo III engines install the coolant deflector
into the block before installing pump on engine (Fig. 3).
Install spacer between the pump and block for
Turbo III only before tightening pump to speci-
fications. Tighten three top screws (Fig. 1) to 28 N Im
(250 in. lbs.) and lower screw to 68 N Im (50 ft. lbs.).
(2) Install bypass/heater hose and lower radiator
hose. (3) Install generator and air conditioning compres-
sor bracket(s). For solid mount bracket see standard
service procedures in Group 9 Engine. (4) Install generator and air conditioning compres-
sor. (5) Refill cooling system. See
Refilling Cooling
System. (6) Install drive belt, See Accessory Drive Belts,
this Group.
WATER PUMPÐ3.0L ENGINE
The 3.0L pump bolts directly to the engine block,
using a gasket for pump to block sealing (Fig. 4). The
pump is serviced as a unit. The water pump is driven by the timing belt. See
Timing System in Group 9, Engine for component re-
moval providing access to water pump.
REMOVAL (1) Drain cooling system. Refer to Draining Cool-
ing System in this group. (2) Remove mounting bolts.
(3) Separate pump from water inlet pipe (Figs. 4
and 5) and remove.
INSPECTION Replace the water pump if it has any of the follow-
ing defects.
Fig. 4 Water PumpÐ3.0L Engine
Fig. 5 Water Pump Inspection
Fig. 3 Coolant DeflectorÐTurbo III
Ä COOLING SYSTEM 7 - 11

(1) Damage or cracks on the pump body.
(2) Coolant leaks, if the shaft seal is leaking, evi-
dent by traces of coolant leaks from vent hole A in
(Fig. 5). (3) Impeller rubs inside of pump.
(4) Excessively loose or rough turning bearing.
INSTALLATION (1) Clean all gasket and O-ring surfaces on pump
and water pipe inlet tube. (2) Install new O-ring on water inlet pipe (Fig. 6).
Wet the O-ring with water to facilitate assembly.
CAUTION: Keep the O-ring free of oil or grease.
(3) Install new gasket on water pump and install
pump inlet opening over water pipe, press assembly
to cause water pipe insertion into pump housing. (4) Install pump to block mounting bolts and
tighten to 27 N Im (20 ft. lbs.).
(5) See Timing System in Engine, Group 9 and in-
stall timing belt. Reassemble engine. (6) Fill cooling system. See Refilling Cooling Sys-
tem.
WATER PUMPÐ3.3L AND 3.8L ENGINES
The pump has a die cast aluminum body and a
stamped steel impeller. It bolts directly to the chain
case cover, using an O-ring for sealing. It is driven
by the back surface of the Poly-V Drive Belt.
REMOVAL (1) Drain Cooling System. Refer to Draining Cool-
ing System in this group. (2) Remove Poly V Drive Belt.
(3) Remove right front lower fender shield.
(4) Remove pump pulley bolts and remove pulley.
(5) Remove pump mounting screws (Fig. 7). Re-
move pump. (6) Remove and discard O-ring seal. (7) Clean O-ring groove and O-ring surfaces on
pump and chain case cover. Take care not to scratch
or gouge sealing surface.
INSPECTION
Replace the water pump if it has any of the follow-
ing defects. (1) Damage or cracks on the pump body.
(2) Coolant leaks; if the seal is leaking, evident by
traces of coolant leaks from vent hole. (3) Loose or rough turning bearing.
(4) Impeller rubs either the pump body or chain-
case cover.
INSTALLATION
(1) Install new O-ring in O-ring groove (Fig. 8).
(2) Install pump to chain case cover. Torque screws
to 12 N Im (105 in. lbs.).
(3) Rotate pump by hand to check for freedom of
movement. (4) Position pulley on pump. Install screws and
torque to 30 N Im (250 in. lbs.).
Fig. 6 Water Pipe O-Ring
Fig. 7 Water PumpÐ3.3L and 3.8L Engines
Fig. 8 Water Pump Body
7 - 12 COOLING SYSTEM Ä