Page 1617 of 2255

FRONT SERVO
DESCRIPTION
The kickdown servo (Fig. 100) consists of a two-
land piston with an inner piston, a piston rod and
guide, and a return spring. The dual-land piston uses
seal rings on its outer diameters and an O-ring for
the inner piston.
OPERATION
The application of the piston is accomplished by
applying pressure between the two lands of the pis-
ton. The pressure acts against the larger lower land
to push the piston downward, allowing the piston rod
to extend though its guide against the apply lever.
Release of the servo at the 2-3 upshift is accom-
plished by a combination of spring and line pressure,
acting on the bottom of the larger land of the piston.
The small piston is used to cushion the application of
the band by bleeding oil through a small orifice in
the larger piston. The release timing of the kickdown
servo is very important to obtain a smooth but firm
shift. The release has to be very quick, just as the
front clutch application is taking place. Otherwise,
engine runaway or a shift hesitation will occur. To
accomplish this, the band retains its holding capacityuntil the front clutch is applied, giving a small
amount of overlap between them.
DISASSEMBLY
(1) Remove seal ring from rod guide (Fig. 101).
(2)
Remove small snap-ring from servo piston rod.
Then remove piston rod, spring and washer from piston.
(3) Remove and discard servo component O-ring
and seal rings.
CLEANING
Clean the servo piston components (Fig. 102) with
solvent and dry them with compressed air.
INSPECTION
Inspect the servo components (Fig. 103). Replace
the springs if collapsed, distorted or broken. Replace
the guide, rod and piston if cracked, bent, or worn.
Discard the servo snap-ring if distorted or warped.
Check the servo piston bore for wear. If the bore is
severely scored, or damaged, it will be necessary to
replace the case.
Replace any servo component if doubt exists about
condition. Do not reuse suspect parts.
ASSEMBLY
Clean and inspect front servo components.
(1) Lubricate new o-ring and seal rings with petro-
leum jelly and install them on piston, guide and rod.
(2) Install rod in piston. Install spring and washer
on rod. Compress spring and install snap-ring (Fig.
104).
Fig. 99 Typical Method Of Measuring Front Clutch
Pack Clearance
1 - FEELER GAUGE
2 - WAVED SNAP-RING
3 - FEELER GAUGE
Fig. 100 Front Servo
1 - VENT
2 - INNER PISTON
3 - PISTON
4 - SPRING
5 - RELEASE PRESSURE
6 - APPLY PRESSURE
7 - PISTON ROD
21 - 164 AUTOMATIC TRANSMISSION - 46REBR/BE
FRONT CLUTCH (Continued)
Page 1618 of 2255
Fig. 101 Front Servo
1 - PISTON RINGS
2 - SERVO PISTON
3 - O-RING
4 - SNAP-RING
5 - PISTON ROD GUIDE
6 - SEAL RING
7 - SNAP-RING
8 - SERVO SPRING
9 - WASHER
10 - SPRING
11 - PISTON ROD
Fig. 102 Front Servo
1 - VENT
2 - INNER PISTON
3 - PISTON
4 - SPRING
5 - RELEASE PRESSURE
6 - APPLY PRESSURE
7 - PISTON ROD
Fig. 103 Front Servo
1 - PISTON RINGS
2 - SERVO PISTON
3 - O-RING
4 - SNAP-RING
5 - PISTON ROD GUIDE
6 - SEAL RING
7 - SNAP-RING
8 - SERVO SPRING
9 - WASHER
10 - SPRING
11 - PISTON ROD
Fig. 104 Front Servo
1 - PISTON RINGS
2 - SERVO PISTON
3 - O-RING
4 - SNAP-RING
5 - PISTON ROD GUIDE
6 - SEAL RING
7 - SNAP-RING
8 - SERVO SPRING
9 - WASHER
10 - SPRING
11 - PISTON ROD
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 165
FRONT SERVO (Continued)
Page 1619 of 2255

OIL PUMP
DESCRIPTION
The oil pump (Fig. 105) is located in the pump
housing inside the bell housing of the transmission
case. The oil pump consists of an inner and outer
gear, a housing, and a reaction shaft support.
OPERATION
As the torque converter rotates, the converter hub
rotates the inner and outer gears. As the gears
rotate, the clearance between the gear teeth
increases in the crescent area, and creates a suction
at the inlet side of the pump. This suction draws
fluid through the pump inlet from the oil pan. As the
clearance between the gear teeth in the crescent area
decreases, it forces pressurized fluid into the pump
outlet and to the valve body.
STANDARD PROCEDURE - OIL PUMP VOLUME
CHECK
Measuring the oil pump output volume will deter-
mine if sufficient oil flow to the transmission oil
cooler exists, and whether or not an internal trans-
mission failure is present.
Verify that the transmission fluid is at the proper
level. Refer to the Fluid Level Check procedure in
this section. If necessary, fill the transmission to the
proper level with MopartATF +4, type 9602, Auto-
matic Transmission Fluid.
(1) Disconnect theTo coolerline at the cooler
inlet and place a collecting container under the dis-
connected line.
CAUTION: With the fluid set at the proper level,
fluid collection should not exceed (1) quart or inter-
nal damage to the transmission may occur.
Fig. 105 Oil Pump Assembly
1 - OIL SEAL 7 - BOLTS (6)
2 - VENT BAFFLE 8 - #1 THRUST WASHER (SELECTIVE)
3 - OIL PUMP BODY 9 - INNER GEAR
4 - GASKET 10 - OUTER GEAR
5 - REACTION SHAFT SUPPORT 11 - ªOº RING
6 - SEAL RINGS
21 - 166 AUTOMATIC TRANSMISSION - 46REBR/BE
Page 1620 of 2255

(2) Run the engineat curb idle speed, with the
shift selector in neutral.
(3) If one quart of transmission fluid is collected in
the container in 20 seconds or less, oil pump flow vol-
ume is within acceptable limits. If fluid flow is inter-
mittent, or it takes more than 20 seconds to collect
one quart of fluid, refer to the Hydraulic Pressure
tests in this section for further diagnosis.
(4) Re-connect theTo coolerline to the transmis-
sion cooler inlet.
(5) Refill the transmission to proper level.
DISASSEMBLY
(1) Mark position of support in oil pump body for
assembly alignment reference. Use scriber or paint to
make alignment marks.
(2) Place pump body on two wood blocks.
(3) Remove reaction shaft support bolts and sepa-
rate support from pump body (Fig. 106).
(4) Remove pump inner and outer gears (Fig. 107).
(5) Remove o-ring seal from pump body (Fig. 108).
Discard seal after removal.
(6) Remove oil pump seal with Remover Tool
C-3981. Discard seal after removal.
OIL PUMP BUSHING REMOVAL
(1) Position pump housing on clean, smooth sur-
face with gear cavity facing down.
(2) Remove bushing with Tool Handle C-4171 and
Bushing Remover SP-3550 (Fig. 109).
REACTION SHAFT SUPPORT BUSHING REMOVAL
(1) Assemble Cup Tool SP-3633, Nut SP-1191 and
Bushing Remover SP-5301 (Fig. 110).
(2) Hold cup tool firmly against reaction shaft.
Thread remover tool into bushing as far as possible
by hand.
(3) Using wrench, thread remover tool an addi-
tional 3-4 turns into bushing to firmly engage tool.
(4) Tighten tool hex nut against cup tool to pull
bushing from shaft. Clean all chips from shaft and
support after bushing removal.
Fig. 106 Reaction Shaft Support
1 - OIL PUMP
2 - REACTION SHAFT SUPPORT
Fig. 107 Pump Gears
1 - GEAR BORE
2 - PUMP BODY
3 - INNER GEAR
4 - OUTER GEAR
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 167
OIL PUMP (Continued)
Page 1621 of 2255

CLEANING
Clean pump and support components with solvent
and dry them with compressed air.
INSPECTION
Check condition of the seal rings and thrust
washer on the reaction shaft support. The seal rings
do not need to be replaced unless cracked, broken, or
severely worn.
Inspect the pump and support components. Replace
the pump or support if the seal ring grooves or
machined surfaces are worn, scored, pitted, or dam-
aged. Replace the pump gears if pitted, worn
chipped, or damaged.
Inspect the pump bushing. Then check the reaction
shaft support bushing. Replace either bushing only if
heavily worn, scored or damaged. It is not necessary
to replace the bushings unless they are actually dam-
aged.Clearance between outer gear and reaction shaft
housing should be 0.010 to 0.063 mm (0.0004 to
0.0025 in.). Clearance between inner gear and reac-
tion shaft housing should be 0.010 to 0.063 mm
(0.0004 to 0.0025 in.). Both clearances can be mea-
sured at the same time by installing the gears in the
pump body and measure pump component clearances
as follows:
(1) Position an appropriate piece of PlastigageŸ
across both gears.
(2) Align the plastigage to a flat area on the reac-
tion shaft housing.
(3) Install the reaction shaft to the pump housing.
(4) Separate the reaction shaft housing from the
pump housing and measure the PlastigageŸ follow-
ing the instructions supplied with it.
Clearance between inner gear tooth and outer gear
should be 0.08 to 0.19 mm (0.0035 to 0.0075 in.).
Measure clearance with an appropriate feeler gauge
(Fig. 111).
Fig. 108 Oil Pump Assembly
1 - OIL SEAL 7 - BOLTS (6)
2 - VENT BAFFLE 8 - #1 THRUST WASHER (SELECTIVE)
3 - OIL PUMP BODY 9 - INNER GEAR
4 - GASKET 10 - OUTER GEAR
5 - REACTION SHAFT SUPPORT 11 - ªOº RING
6 - SEAL RINGS
21 - 168 AUTOMATIC TRANSMISSION - 46REBR/BE
OIL PUMP (Continued)
Page 1622 of 2255

Clearance between outer gear and pump housing
should be 0.10 to 0.19 mm (0.004 to 0.0075 in.). Mea-
sure clearance with an appropriate feeler gauge.
ASSEMBLY
OIL PUMP BUSHING
(1) Assemble Tool Handle C-4171 and Bushing
Installer SP-5118 (Fig. 112).
(2) Place bushing on installer tool and start bush-
ing into shaft.
(3) Tap bushing into place until Installer Tool
SP-5118 bottoms in pump cavity. Keep tool and bush-
ing square with bore. Do not allow bushing to become
cocked during installation.
(4) Stake pump bushing in two places with blunt
punch. Remove burrs from stake points with knife
blade (Fig. 113).
REACTION SHAFT SUPPORT BUSHING
(1) Place reaction shaft support upright on a clean,
smooth surface.
(2) Assemble Bushing Installer Tools C-4171 and
SP-5302. Then slide new bushing onto installer tool
(Fig. 114).(3) Start bushing in shaft. Tap bushing into shaft
until installer tool bottoms against support flange.
(4) Clean reaction shaft support thoroughly after
bushing replacement (to remove any chips).
Fig. 109 Oil Pump Bushing
1 - SPECIAL TOOL C-4171
2 - SPECIAL TOOL SP-3550
3 - BUSHING
4 - SPECIAL TOOL SP-5118
5 - SPECIAL TOOL C-4171
6 - PUMP HOUSING
Fig. 110 Reaction Shaft Bushing
1 - SPECIAL TOOL SP-1191
2 - SPECIAL TOOL C-4171
3 - SPECIAL TOOL SP-3633
4 - SPECIAL TOOL SP-5301
5 - SPECIAL TOOL SP-5302
6 - BUSHING
7 - REACTION SHAFT
8 - BUSHING
Fig. 111 Checking Pump Gear Tip Clearance
1 - FEELER GAUGE
2 - INNER GEAR
3 - OUTER GEAR
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 169
OIL PUMP (Continued)
Page 1623 of 2255

OIL PUMP BODY
(1) Lubricate pump gears with transmission fluid
and install them in pump body.(2) Install thrust washer on reaction shaft support
hub. Lubricate washer with petroleum jelly or trans-
mission fluid before installation.
(3) If reaction shaft seal rings are being replaced,
install new seal rings on support hub. Lubricate seal
rings with transmission fluid or petroleum jelly after
installation. Squeeze each ring until ring ends are
securely hooked together.
CAUTION: The reaction shaft support seal rings will
break if overspread, or twisted. If new rings are
being installed, spread them only enough for instal-
lation. Also be very sure the ring ends are securely
hooked together after installation. Otherwise, the
rings will either prevent pump installation, or break
during installation.
(4) Align and install reaction shaft support on
pump body.
(5) Install bolts attaching reaction shaft support to
pump. Tighten bolts to 20 N´m (175 in. lbs.) torque.
(6) Install new pump seal with Installer Tool
C-3860-A (Fig. 115). Use hammer or mallet to tap
seal into place.
Fig. 112 Oil Pump Bushing
1 - SPECIAL TOOL C-4171
2 - SPECIAL TOOL SP-3550
3 - BUSHING
4 - SPECIAL TOOL SP-5118
5 - SPECIAL TOOL C-4171
6 - PUMP HOUSING
Fig. 113 Staking-Deburring Oil Pump Bushing
1 - TWO STAKES
2 - NARROW BLADE
3 - BLUNT PUNCH
Fig. 114 Reaction Shaft Bushing
1 - SPECIAL TOOL SP-1191
2 - SPECIAL TOOL C-4171
3 - SPECIAL TOOL SP-3633
4 - SPECIAL TOOL SP-5301
5 - SPECIAL TOOL SP-5302
6 - BUSHING
7 - REACTION SHAFT
8 - BUSHING
21 - 170 AUTOMATIC TRANSMISSION - 46REBR/BE
OIL PUMP (Continued)
Page 1624 of 2255

(7) Install new o-ring on pump body. Lubricate oil
seal and o-ring with petroleum jelly.
(8) Cover pump assembly to prevent dust entry
and set aside for assembly installation.
OUTPUT SHAFT FRONT
BEARING
REMOVAL
(1) Remove overdrive unit from the vehicle.
(2) Remove overdrive geartrain from housing.
(3) Remove snap-ring holding output shaft front
bearing to overdrive geartrain. (Fig. 116).
(4) Pull bearing from output shaft.
INSTALLATION
(1) Place replacement bearing in position on
geartrain with locating retainer groove toward the
rear.
(2) Push bearing onto shaft until the snap-ring
groove is visible.
(3) Install snap-ring to hold bearing onto output
shaft.
(4) Install overdrive geartrain into housing.
(5) Install overdrive unit in vehicle.
OUTPUT SHAFT REAR
BEARING
REMOVAL
(1) Remove overdrive unit from the vehicle. (Refer
to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC/
OVERDRIVE - REMOVAL)
(2) Remove overdrive geartrain from housing.
(3) Remove snap-ring holding output shaft rear
bearing into overdrive housing (Fig. 117).
(4) Using a suitable driver inserted through the
rear end of housing, drive bearing from housing.
Fig. 115 Oil Pump Seal
1 - SPECIAL TOOL C-3860-A
2 - PUMP BODY
3 - PUMP SEAL
Fig. 116 Output Shaft Front Bearing
1 - OUTPUT SHAFT FRONT BEARING
2 - SNAP-RING
3 - OUTPUT SHAFT
4 - GROOVE TO REAR
5 - OVERDRIVE GEARTRAIN
Fig. 117 Output Shaft Rear Bearing
1 - OUTPUT SHAFT REAR BEARING
2 - OVERDRIVE HOUSING
3 - SNAP-RING
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 171
OIL PUMP (Continued)