Hydraulic Pressure Tests - Jeep KJ 2005 Service Manual

21 - 48 AUTOMATIC TRANSMISSION - 42RLE
AUTOMATIC TRANSMISSION - 42RLE (Continued)
ELEMENTS IN USE AT EACH POSITION OF SELECTOR LEVER
Shift Lever
Position
Underdrive
P - PARK
R - REVERSE
N - NEUTRAL
OD -
OVERDRIVE
First
Second
Direct
Overdrive
D - DRIVE*
First
Second
Direct
L - LOW*
First
Second
Direct
* Vehicle upshift and downshift speeds are increased when in these selector positions.
The process of elimination can be used to detect
any unit which slips and to confirm proper operation
of good units. Road test analysis can diagnose slip-
ping units, but the cause of the malfunction cannot
be determined. Practically any condition can be
caused by leaking hydraulic circuits or sticking
valves.

HYDRAULIC PRESSURE TESTS

Pressure testing is a very important step in the
diagnostic procedure. These tests usually reveal the
cause of most transmission problems.
Before performing pressure tests, be certain that
fluid level and condition, and shift cable adjustments
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 the wheels to turn, and position
tachometer so it can be read.
Using special adapters L-4559, attach 300 psi
gauge(s) C-3293SP to the port(s) required for test
being conducted.
Test port locations are shown in the Pressure Taps
graphic. (Fig. 8)
INPUT CLUTCHES
Overdrive
X
X
X X
X
X
X
X X
X
X
X X
Reverse
X
Fig. 8 Pressure Taps
1 - TORQUE CONVERTER CLUTCH OFF
2 - REVERSE
3 - LOW/REVERSE
4 - 2/4
5 - UNDERDRIVE
6 - TORQUE CONVERTER CLUTCH ON
7 - OVERDRIVE
HOLDING CLUTCHES
2/4 Low/Reverse
X
X
X
X
X
X
X
X
X
X
KJ