lock CHEVROLET DYNASTY 1993 Service Manual

CAUTION: Before removing the gearshift housing,
reverse the lock pin (so the long end is down) and
insert lock pin into the same threaded hole. This
procedure will save time when the gearshift hous-
ing assembly is reinstalled.
Fig. 14 A-523/A-543/A-568 Shift Forks and Shift Rail Components
Fig. 15 Gearshift Housing Bolts
Fig. 16 Gearshift Housing Removed
21 - 10 TRANSAXLE Ä

To install gearshift housing, be sure to reverse
the lock pin in the housing to lock the selector
shaft in the 3-4 neutral position.
CAUTION: Install roller detents so roller and slots are
parallel with shift rails.
Remove or install 3-4 lug roll pin, 3-4 fork roll pin,
and reverse lug roll pin using the above procedure.
CAUTION: If any roll pin falls out, retrieve roll pin from
bottom of case.
Fig. 19 Install 1-2 Shift Lug Roll Pin
Fig. 20 Remove 1-2 Shift Fork Roll Pin
Fig. 21 Reverse Pivot Lever
Fig. 17 Remove Roller Detents
Fig. 18 Remove 1-2 shift Lug Roll Pin
Ä TRANSAXLE 21 - 11

Fig. 22 5th Shift Rail C-Clip
Fig. 23 5th Shift Rail and Shift Lug
Fig. 24 5th Shift Lug with Interlock Pin
Fig. 25 5th Shift Lug Properly Installed
Fig. 26 Reverse Shift Rail and Shift Lug
Fig. 27 3-4 Shift Rail and Shift Lug
21 - 12 TRANSAXLE Ä

The C-Clip groves in the selector shaft will
damage the oil seal. Install oil seal after selector
shaft is installed. Always use a new oil seal when
selector shaft is removed. Proper torque to the 5-R blocker attaching
bolts is very important (Fig. 8).
Fig. 4 Remove Oil Seal
Fig. 5 Install Oil Seal
Fig. 6 Remove Vent Cap
Fig. 7 Crossover Shaft Roll Pin
Fig. 8 5-R Blocker Attaching Bolts
Fig. 9 5-R Blocker Assembly
21 - 22 TRANSAXLE Ä

CAUTION: Always install new ring gear bolts. Bolts
must be properly torqued (See Tightening Refer-
ence). After assembling the differential side gears, pinion
gears and pinion gears withthe pinion gear washers,
but without the side gear thrust washers. Rotate the
assembly two full revolutions both clockwise and
counterclockwise. Set up dial indicator as shown and record end play.
Rotate side gear 90 degrees and record another end
play. Again, rotate side gear 90 degrees and record a
final end play. Using the smallest end play recorded, shim that
side gear to within .001 to .013 inch. The other side
gear should be checked using the same procedure.
Fig. 5 Remove or Install Ring Gear Bolts and Ring Gear
Fig. 6 Remove Pinion Shaft Roll Pin
Fig. 7 Remove or Install Pinion Shaft
Fig. 8 Remove or Install Pinion Gears, Side Gears,and Thrust Washers by Rotating Side Gears to Opening in Case
Fig. 9 Differential Gears
21 - 28 TRANSAXLE Ä

CAUTION: See Figure 14 to determine side gear
thrust washer thickness. Side gear end play must be
within.001 to .013 inch.Four select thrust washes are available: .032, .037,
.042, and .047 inch.
Side gear thrust washers are available in 4
select thicknesses: .032, .037, .042, and .047 inch. Measure the depth from the differential case to the
machined surface in 3 places, as shown in Figure 13.
Then measure the height of raised stepon the ring
gear. The difference, minus the proper side gear end
play (.001 to .013 inch) is the proper thrust washer
thickness. For the other side gear: After assembling the differ-
ential side gears, pinion gears, and pinion gears with
the pinion gear washers but withoutthe side gear
thrust washers. Rotate the assembly two full revolu-
tions both clockwise and counterclockwise. Set up dial indicator as shown in Figure 14 and
record end play. Rotate side gear 90 degrees and record another end play. Again, rotate side gear 90
degrees and record a final end play.
Using the smallest end play recorded, shim that side
gear to within .001 to .013 inch.
CAUTION: After reassembly of the differential assem-
bly, insert the inner joint housing spline from a drive
shaft into the side gear. By hand, turn the side gear
with the joint housing spline. If the side gear will NOT
turn, or it feels very tight, remove the ring gear and
install a thinner side gear thrust washer.
Side gear thrust washers are available in four
select thicknesses: .032, .037, .042, and .047 inch.
BEARING ADJUSTMENT PROCEDURE
GENERAL RULES ON SERVICING BEARINGS
(1) Take extreme care when removing and installing
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 bear-
Fig. 12 Differential Gears
Fig. 13 Determine Proper Side Gear Thrust Washer Thickness
Fig. 10 Remove or Install Pinion Shafts
Fig. 11 Remove or Install 4 Pinion Gears and 2 Side Gears
Ä TRANSAXLE 21 - 31

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

Unless the condition is obvious, like no drive in D
range first gear only. The transaxle should never be
disassembled until hydraulic pressure tests have
been performed.
HYDRAULIC PRESSURE TESTS
Pressure testing is a very important step in the di-
agnostic procedure. These tests usually reveal the
cause of most transaxle problems. Before performing pressure tests, be certain that
fluid level and condition, and control cable adjust-
ments have been checked and approved. Fluid must be at operating temperature (150 to 200
degrees F.). Install an engine tachometer, raise vehicle on hoist
which allows front wheels to turn, and position ta-
chometer so it can be read. Disconnect throttle cable and shift cable from tran-
saxle levers so they can be controlled from outside
the vehicle. Attach 150 psi gauges to ports required for test be-
ing conducted. A 300 psi gauge (C-3293) is required
for reverse pressure test at rear servo.
Test port locations are shown in (Fig. 3).
TEST ONE (SELECTOR IN 1)
(1) Attach gauges to lineandlow-reverse ports
(Fig. 3). (2) Operate engine at 1000 rpm for test.
(3) Move selector lever on transaxle all the way
rearward ( 1position).
(4) Read pressures on both gauges as throttle lever
on transaxle is moved from full clockwise position to
full counterclockwise position. (5) Line pressure should read 52 to 58 psi with
throttle lever clockwise and gradually increase, as le-
ver is moved counterclockwise, to 80 to 88 psi. (6) Low-reverse pressure should read the same as
line pressure within 3 psi. (7) This tests pump output, pressure regulation,
and condition of rear clutch and rear servo hydraulic
circuits.
TEST TWO (SELECTOR IN 2)
(1) Attach one gauge to line pressureport and
tee another gauge into lower cooler line fitting. This
will allow you to read lubricationpressure (Fig 3).
(2) Operate engine at 1000 rpm for test.
Fig. 3 Transaxle (Left Side)
21 - 42 TRANSAXLE Ä

(3) Move selector lever on transaxle one detent
forward from full rearward position. This is selector
2 position.
(4) Read pressures on both gauges as throttle lever
on transaxle is moved from full clockwise position to
full counterclockwise position. (5) Line pressure should read 52 to 58 psi with
throttle lever clockwise and gradually increase, as le-
ver is moved counterclockwise, to 80 to 88 psi. (6) Lubrication pressure should be 10 to 25 psi
with lever clockwise and 10 to 35 psi with lever full
counterclockwise. (7) This tests pump output, pressure regulation,
and condition of rear clutch and lubrication hydrau-
lic circuits.
TEST THREE (SELECTOR IN D)
(1) Attach gauges to lineandkickdown release
ports (Fig. 3). (2) Operate engine at 1600 rpm for test.
(3) Move selector lever on transaxle two detents
forward from full rearward position. This is selector
D position.
(4) Read pressures on both gauges as throttle lever
on transaxle is moved from full clockwise position to
full counterclockwise position. (5) Line pressure should read 52 to 58 psi with
throttle lever clockwise and gradually increase, as le-
ver is moved counterclockwise to 80 to 88 psi. (6) Kickdown release is pressurized only in direct
drive and should be same as line pressure within 3
psi, up to kickdown point. (7) This tests pump output, pressure regulation,
and condition of rear clutch, front clutch, and hy-
draulic circuits.
TEST FOUR (SELECTOR IN REVERSE)
(1) Attach 300 psi gauge to low-reverseport (Fig.
3). (2) Operate engine at 1600 rpm for test.
(3) Move selector lever on transaxle four detents
forward from full rearward position. This is selector
R position.
(4) Low-reverse pressure should read 180 to 220
psi with throttle lever clockwise and gradually in-
crease, as lever is moved counterclockwise to 260 to
300 psi. (5) This tests pump output, pressure regulation,
and condition of front clutch and rear servo hydraulic
circuits. (6) Move selector lever on transaxle to Dposition
to check that low-reverse pressure drops to zero. (7) This tests for leakage into rear servo, due to
case porosity, which can cause reverse band burn
out.
TEST RESULT INDICATIONS
(1) If proper line pressure, minimum to maximum, is
found in any one test, the pump and pressure regulator
are working properly. (2) Low pressure in D, 1, and 2but correct pressure
in Rindicates rear clutch circuit leakage.
(3) Low pressure in D and Rbut correct pressure in
1 indicates front clutch circuit leakage.
(4) Low pressure in R and 1but correct pressure in
2 indicates rear servo circuit leakage.
(5) Low line pressure in all positions indicates a
defective pump, a clogged filter, or a stuck pressure
regulator valve.
GOVERNOR PRESSURE
Test only if transaxle shifts at wrong vehicle speeds
when throttle cable is correctly adjusted. (1) Connect a 0-150 psi pressure gauge to governor
pressure take-off point, located at lower right side of
case, below differential cover (Fig. 3). (2) Operate transaxle in third gear to read pres-
sures. The governor pressure should respond smoothly
to changes in mph and should return to 0 to 3 psi when vehicle is stopped. High pressure at
standstill (above 3 psi) will prevent the transaxle from
downshifting.
THROTTLE PRESSURE
No gauge port is provided for throttle pressure.
Incorrect throttle pressure should only be suspected if
part throttle upshift speeds are either delayed or occur
too early, with a correctly adjusted throttle cable.
Engine runaway on either upshifts or downshifts can
also be an indicator of incorrect (low) throttle pressure
setting, or misadjusted throttle cable. In no case should throttle pressure be adjusted until
the transaxle throttle cable adjustment has been veri-
fied to be correct.
CLUTCH AND SERVO AIR PRESSURE TESTS
A no drive condition might exist even with correct
fluid pressure, because of inoperative clutches or
bands. The inoperative units, clutches, bands, and
servos can be located through a series of tests by
substituting air pressure for fluid pressure (Fig. 4). The front and rear clutches, kickdown servo, and
low-reverse servo may be tested by applying air pres-
sure to their respective passages after the valve body assembly has been removed. To make
air pressure tests, proceed as follows: Compressed air supply must be free of all dirt
or moisture. Use a pressure of 30 psi. Remove oil pan and valve body See Disassembly-
Subassembly Removal .
FRONT CLUTCH
Apply air pressure to front clutch applypassage and
listen for a dull thudwhich indicates that front
Ä TRANSAXLE 21 - 43