checking oil CHEVROLET DYNASTY 1993 Repair Manual

plus (constant) preload of 0.254mm (.010 in.).
Combine shims, if necessary, to obtain a shim within
.05mm (.002 inch) of the required shim (see Shim
Chart for proper shims).(7) Remove differential bearing retainer. Remove
bearing cup and gauging shim. Properly install oil
baffle. Be sure oil baffle is not damaged. Install
shim(s) selected in step (6). Then press in the bearing
cup into differential bearing retainer. (8) Using a 1/16 inch bead of MOPAR tGasket
Maker, Loctite 518, or equivalent for gasket, install
differential bearing retainer. Torque all bolts (See
Tightening Reference). (9) Using Special Tool C-4995 and an inch-pound
torque wrench, check turning torque of the differential
assembly in clockwise and counterclockwise directions
(Fig. 4). The turning torque should be 9 to 14 in.
lbs. for new bearings or a minimum of 6 in. lbs.
for used bearings. If the turning torque is too
high, install a .05mm (.002 inch) thinner shim. If
the turning torque is too low, install a .05mm
(.002 inch) thicker shim. (10) Recheck turning torque. Repeat Step (9) until
the proper turning torque is obtained.
Fig. 4 Checking Differential Bearing Turning Torque
DIFFERENTIAL BEARING SHIM CHART
21 - 34 TRANSAXLE Ä

TORQUE CONVERTER CLUTCH
The torque converter clutch is standard on all ve-
hicles. It is activated only in direct drive and is con-
trolled by the engine electronics. A solenoid on the
valve body, is powered by the powertrain control mod-
ule to activate torque converter clutch.
HYDRAULIC CONTROL SYSTEM
The hydraulic control circuits show the position of
the various valves. They indicate those under hydrau-
lic pressure for all operations of the transaxle. The hydraulic control system makes the transaxle
fully automatic, and has four important functions to
perform. In a general way, the components of any
automatic control system may be grouped into the
following basic groups: The pressure supply system, the pressure regulating
valves, the flow control valves, the clutches, and band
servos. Taking each of these basic groups or systems in turn,
the control system may be described as follows:
PRESSURE SUPPLY SYSTEM
The pressure supply system consists of an oil pump
driven by the engine through the torque converter. The
single pump furnishes pressure for all the hydraulic
and lubrication requirements. Oil pump housing
assemblies are available with preselected pump
gears.
PRESSURE REGULATING VALVES
The pressure regulating valve controls line pressure
dependent on throttle opening. The governor valve
transmits regulated pressure to the valve body (in
conjunction with vehicle speed) to control upshift and
downshift. The throttle valve transmits regulated pressure to
the transaxle (dependent on throttle position) to con-
trol upshift and downshift.
FLOW CONTROL VALVES
The manual valve provides the different transaxle
drive ranges as selected by the vehicle operator. The 1-2 shift valve automatically shifts the transaxle
from first to second or from second to first, depending
on the vehicle operation. The 2-3 shift valve automatically shifts the transaxle
from second to third or from third to second depending
on the vehicle operation. The kickdown valve makes possible a forced down-
shift from third to second, second to first, or third to
first (depending on vehicle speed). This can be done by
depressing the accelerator pedal past the detent ``feel''
near wide open throttle. The shuttle valve has two separate functions and
performs each independently of the other. The first
provides fast release of the kickdown band, and
smooth front clutch engagement, when the driver makes a
lift-footupshift from second to third. The
second function of the shuttle valve is to regulate the
application of the kickdown servo and band when
making third to second kickdown. The by-pass valve provides for smooth application of
the kickdown band on 1-2 upshifts. The torque converter clutch solenoid allows for the
electronic control of the clutch inside the torque con-
verter. It also disengages the torque converter at closed
throttle, during engine warm-up, and during part-
throttle acceleration. The switch valve directs oil to apply the torque
converter clutch in one position and releases the torque
converter clutch in the other position.
CLUTCH, BAND SERVO, AND ACCUMULATOR
The front and rear clutch pistons, and both servo
pistons are moved hydraulically to engage the clutches
and apply the bands. The pistons are released by
spring tension when hydraulic pressure is released. On
the 2-3 upshift, the kickdown servo piston is released
by spring tension and hydraulic pressure. The accumulator controls the hydraulic pressure on
the apply side of the kickdown servo during the 1-2
upshift; thereby, cushioning the kickdown band appli-
cation at any throttle position.
GEARSHIFT AND PARKING LOCK CONTROLS
The transaxle is controlled by a lever typegearshift
incorporated within the console or the steering column.
The control has six selector lever positions: P (park), R
(reverse), N (neutral), and D (drive), 2 (second), and 1
(first). The parking lock is applied by moving the
selector lever past a gate to the Pposition. Do not
apply the parking lock until the vehicle has
stopped; otherwise, a severe banging noise will
occur.
THREE SPEED TORQUEFLITE GENERAL DIAGNO-
SIS
Automatic transaxle malfunctions may be caused by
four general conditions:
² Poor engine performance
² Improper adjustments
² Hydraulic malfunctions
² Mechanical malfunctions.
Diagnosis of these problems should always begin by
checking the easily accessible variables: fluid level and
condition, gearshift cable adjustment, and throttle
pressure cable adjustment. Then perform a road test to
determine if the problem has been corrected or that
more diagnosis is necessary. If the problem exists after
the preliminary tests and corrections are completed,
hydraulic pressure tests should be performed.
21 - 36 TRANSAXLE Ä

CAUTION: Prevent manual shaft rotation during in-
stallation and removal. (2) With rotary motion, install converter hub seal
cup over input shaft. It must go through the con-
verter hub seal until the cup bottoms against the
pump gear lugs. Secure with cup retainer strap using
starter upper hole and opposite bracket hole. (3) Attach and clamp hose from nozzle of Tool
C-4080 to the upper cooler line fitting position in
case.
CAUTION: Do not, under any circumstances, pres-
surize a transaxle to more than 10 psi.
(4) Pressurize the transaxle using Tool C-4080 un-
til the pressure gauge reads 8 psi. Position transaxle
so that pump housing and case front may be covered
with soapy solution of water. Leaks are sometimes
caused by porosity in the case or pump housing. If a leak source is located, that part and all associ-
ated seals, O-rings, and gaskets should be replaced
with new parts.
GEARSHIFT LINKAGE ADJUSTMENT
Normal operation of the transmission range switch
(PRNDL) and park/neutral position switch provides a
quick check to confirm proper manual linkage adjust-
ment. Move the selector level slowly upward until it
clicks into the ``P'' Park notch in the selector gate. If
the starter will operate the ``P'' position is correct. After checking ``P'' position, move selector toward
``N'' Neutral position until lever drops in the ``N''
stop. If the starter will also operate at this point the
gearshift linkage is properly adjusted.
CAUTION:When it is necessary to disassemble link-
age cable from levers, which use plastic grommets
as retainers, the grommets should be replaced with
new grommets. Use a prying tool to force rod from
grommet in lever, then cut away old grommet. Use
pliers to snap new grommet into lever and rod into
grommet.
(1) Set parking brake.
(2) Place gearshift lever in P(PARK) position.
(3) Loosen clamp bolt on gearshift cable bracket.
(4) Column shift: Insure that preload adjustment
spring engages fork on transaxle bracket. (5) Pull the shift lever by hand to the front detent
position (PARK) and tighten lock screw to 11 N Im
(100 in. lbs.). Gearshift linkage should now be prop-
erly adjusted. (6) Check adjustment as follows:(a) Detent position for neutral and drive should
be within limits of hand lever gate stops. (b) Key start must occur only when shift lever is
in park or neutral positions.
ALUMINUM THREAD REPAIR
Damaged or worn threads in the aluminum tran-
saxle case and valve body can be repaired by the use
of Heli-Coils, or equivalent. This repair consists of
drilling out the worn-out damaged threads. Then tap
the hole with a special Heli-Coil tap, or equivalent,
and installing a Heli-Coil insert, or equivalent, into
the hole. This brings the hole back to its original
thread size. Heli-Coil, or equivalent, tools and inserts are
readily available from most automotive parts suppli-
ers.
COOLERS AND TUBES REVERSE FLUSHING
When a transaxle failure has contaminated the
fluid, the oil cooler(s) must be flushed and the cooler
bypass valve in the transaxle must be replaced. The
torque converter must also be replaced with an ex-
change unit. This will insure that metal particles or
sludged oil are not later transferred back into the re-
conditioned (or replaced) transaxle.
Fig. 5 Torque Converter Hub Seal Cup
Fig. 6 Hub Seal Cup Retaining Strap
21 - 98 TRANSAXLE Ä

Now that both shaft assemblies and thrust washers
are properly installed, reinstall overdrive clutch and
reverse clutch as shown in Figures 20 through 28.
Rechecking these clutch clearances is not neces-
sary, as they were set and approved previously.
VALVE BODY-RECONDITION
Prior to removing any transaxle subassemblies, plug
all openings and thoroughly clean exterior of the unit,
preferably by steam. Cleanliness through entire disas-
sembly and assembly cannot be overemphasized. When
disassembling, each part should be washed in a suit-
able solvent, then dried by compressed air. Do not
wipe parts with shop towels. All mating surfaces in
the transaxles are accurately machined; therefore,
careful handling of all parts must be exercised to avoid
nicks or burrs. Tag all springs, as they are removed, for reas-
sembly identification.
Fig. 33 Install No. 3 Thrust Washer
Fig. 34 Install No. 3 Thrust Plate
Fig. 35 Install Overdrive Shaft Assembly
Fig. 36 Input Clutch Assembly
Fig. 1 Oil Pan Bolts
21 - 132 TRANSAXLE Ä

When installing valve body assembly onto tran-
saxle, observe Figure 5. Guide park rod rollers into
guide bracket, while shifting manual lever assembly
out of the installation position.
OIL PUMP SEAL REPLACE DIFFERENTIAL REPAIR
The transfer shaft should be removed for differen-
tial repair and bearing turning torque checking.
Fig. 16 Remove Oil Pump Seal
Fig. 17 Install Oil Pump Seal
Fig. 1 Remove Extension Seal
Fig. 2 Install New Seal Into Extension
Fig. 14 Remove or Install Dual Retainer Plate
Fig. 15 Remove or Install Retainer Plate
21 - 136 TRANSAXLE Ä

Four select thrust washers are available: .032,
.037, .042, and .047 inch.
CAUTION: Side gear end play must be within .001
to .013 inch.
Four select thrust washers are available: .032,
.037, .042, and .047 inch.
DETERMINING SHIM THICKNESS
Shim thickness need only be determined if any of
the following parts are replaced:
² Transaxle case
² Differential carrier
² Differential bearing retainer
² Extension housing
² Differential bearing cups and cones
Refer to Bearing Adjustment Procedure in rear
of this section to determine proper shim thickness for
correct bearing preload and proper bearing turning
torque.
Fig. 21 Checking Side Gear End Play
Fig. 22 Remove Oil Seal
Fig. 23 Install New Oil Seal
Fig. 24 Remove Bearing Cup
Fig. 25 Differential Bearing Retainer
21 - 140 TRANSAXLE Ä

When rebuilding, reverse the above procedure.
Remove old sealant before applying new seal-
ant. Use MOPAR tAdhesive Sealant on retainer
to seal retainer to case.
BEARING ADJUSTMENT PROCEDURE
GENERAL RULES ON SERVICING BEARINGS
(1) Take extreme care when removing and in stalling
bearing cups and cones. Use only an arbor press for
installation, as a hammer may not properly align the
bearing cup or cone. Burrs or nicks on the bearing seat
will give a false end play reading, while gauging for
proper shims. Improperly seated bearing cup and cones
are subject to low-mileage failure. (2) Bearing cups and cones should be replaced if they
show signs of pitting or heat distress. If distress is seen on either the cup or bearing rollers,
both cup and cone must be replaced. Bearing end play and drag torque specifica-
tions must be maintained to avoid premature
bearing failures. Used (original) bearing may lose up to 50
of the original drag torque after break-in.
All bearing adjustments must be made with no
other component interference or gear inter-
mesh, except the transfer gear bearing. Oil all bearings before checking turning torque.OUTPUT GEAR BEARING
With output gear removed:
(1) Install a 4.50 mm (0.177 inch) gauging shim on
the rear carrier assembly hub, using grease to hold the
shim in place. (2) Install output gear and bearing assembly. Torque
to 271 N Im (200 ft. lbs.).
(3) To measure bearing end play:
Fig. 26 Install Bearing Cup
Fig. 27 Checking Differential End Play
Fig. 28 Tool L-4436 and Torque Wrench
Fig. 29 Checking Differential Bearings Turning Torque
Ä TRANSAXLE 21 - 141