that is a conventional hydraulic/mechanical assembly
controlled with adaptive electronic controls and mon-
itors. The hydraulic system of the transmission con-
sists

the

transmission

fluid,

fluid

passages,

hydraulic valves, and various line pressure control
components. An input clutch assembly which houses
the underdrive, overdrive, and reverse clutches is
used. It also utilizes separate holding clutches: 2nd/
4th gear and Low/Reverse. The primary mechanical
components of the transmission consist of the follow-
ing:

• Three multiple disc input clutches

• Two multiple disc holding clutches

• Four hydraulic accumulators

• Two planetary gear sets

• Hydraulic oil pump

• Valve body

• Solenoid/Pressure switch assembly

Control of the transmission is accomplished by

fully adaptive electronics. Optimum shift scheduling
is accomplished through continuous real-time sensor
feedback information provided to the Transmission
Control Module (TCM) portion of the Powertrain
Control Module (PCM).

The TCM is the heart of the electronic control sys-

tem and relies on information from various direct
and indirect inputs (sensors, switches, etc.) to deter-
mine driver demand and vehicle operating condi-
tions. With this information, the TCM can calculate
and perform timely and quality shifts through vari-
ous output or control devices (solenoid pack, trans-
mission control relay, etc.).

The TCM also performs certain self-diagnostic

functions and provides comprehensive information
(sensor data, DTC’s, etc.) which is helpful in proper
diagnosis and repair. This information can be viewed
with the DRB

t scan tool.

21 - 38

AUTOMATIC TRANSMISSION - 42RLE

Fig.

42RLE

Automatic

ransmission

AUTOMATIC TRANSMISSION - 42RLE

21 - 39

AUTOMATIC TRANSMISSION - 42RLE (Continued)

TRANSMISSION IDENTIFICATION

The 42RLE transmission can be identified by a

barcode label that is affixed to the upper left area of
the bellhousing.

The label contains a series of digits that can be

translated into useful information such as transmis-
sion part number (10), date of manufacture (4, 5),
manufacturing origin (2), assembly line identifier (6),
build sequence number (7), etc. (Fig. 2).

If the tag is not legible or is missing, the “PK”

number, which is stamped into the left rear flange of
the transmission case, can be referred to for identifi-
cation. The entire part number, build code, and
sequence number are stamped into the flange.

OPERATION

The 42RLE transmission ratios are:

First

2.84 : 1

Second

1.57 : 1

Third

1.00 : 1

Overdrive

0.69 : 1

Reverse

2.21 : 1

1 - DRIVEPLATE

6 - REVERSE CLUTCH

11 - STUB SHAFT

2 - TORQUE CONVERTER

7 - FRONT PLANET CARRIER

12 - LOW/REVERSE CLUTCH

3 - INPUT SHAFT

8 - REAR PLANET CARRIER

13 - 2/4 CLUTCH

4 - UNDERDRIVE CLUTCH

9 - OUTPUT SHAFT

14 - OIL PUMP

5 - OVERDRIVE CLUTCH

10 - SNAP RING

Fig. 2 Identification Label Breakdown

1 - T=TRACEABILITY
2 - SUPPLIER CODE (PK=KOKOMO)
3 - COMPONENT CODE (TK=KOKOMO TRANSMISSION)
4 - BUILD DAY (350=DEC. 15)
5 - BUILD YEAR (1=2001)
6 - ASSEMBLY LINE CODE
7 - BUILD SEQUENCE NUMBER
8 - LAST THREE OF P/N
9 - CHANGE LEVEL
10 - TRANSMISSION PART NUMBER
11 - P=PART NUMBER

21 - 40

AUTOMATIC TRANSMISSION - 42RLE

AUTOMATIC TRANSMISSION - 42RLE (Continued)

FIRST GEAR POWERFLOW

In first gear range, torque input is through the

underdrive clutch (1) (Fig. 3) to the underdrive hub
assembly. The underdrive hub is splined to the rear
sun gear. When the underdrive clutch is applied, it
rotates the underdrive hub and rear sun gear. The
L/R clutch (2) is applied to hold the front carrier/rear
annulus assembly. The rear sun gear drives the rear
planetary pinion gears. The rear planetary pinion
gears are forced to walk around the inside of the sta-
tionary rear annulus gear. The pinions are pinned to
the rear carrier and cause the rear carrier assembly
to rotate as they walk around the annulus gear. This
provides the torque output for first gear. The other
planetary gearset components are freewheeling. The
first gear ratio is 2.84:1.

Fig. 3 First Gear Powerflow

1 - UNDERDRIVE CLUTCH APPLIED (Turns Rear Sun)

2 - LOW-REVERSE CLUTCH APPLIED (Holds Rear Annulus/Front
Carrier)

AUTOMATIC TRANSMISSION - 42RLE

21 - 41

AUTOMATIC TRANSMISSION - 42RLE (Continued)

Content .. 485 486 487 488 ..