Jeep cherokee 2000 Service Manual page 999

XJ
DESCRIPTION AND OPERATION (Continued)
TRANSMISSION IDENTIFICATION
Transmission identification numbers are stamped
on the left side of the case just above the oil pan gas-
ket surface (Fig. 2). Refer to this information when
ordering replacement parts.
Fig. 2 Transmission Part Number And Serial
Number Location
1 – PART NUMBER
2 – BUILD DATE
3 – SERIAL NUMBER
TRANSMISSION GEAR RATIOS
Forward gear ratios are:
• 2.74:1 (first gear)
• 1.54:1 (second gear)
• 1.00:1 (third gear)
AUTOMATIC TRANSMISSION—30RH
OPERATION
The application of each driving or holding compo-
nent is controlled by the valve body based upon the
manual lever position and governor pressure. The
governor pressure is a variable pressure input to the
valve body and is one of the signals that a shift is
necessary. First through third gear are obtained by
selectively applying and releasing the different
clutches and bands. Engine power is thereby routed
to the various planetary gear assemblies which com-
bine with the overrunning clutch assembly to gener-
ate the different gear ratios. The torque converter
clutch is hydraulically applied and is released when
fluid is vented from the hydraulic circuit by the
torque converter control (TCC) solenoid on the valve
body. The torque converter clutch is controlled by the
Powertrain Control Module (PCM). The torque con-
verter clutch engages in third gear when the vehicle
is cruising on a level plane after the vehicle has
warmed up. The torque converter clutch will disen-
gage momentarily when an increase in engine load is
sensed by the PCM, such as when the vehicle begins
to go uphill or the throttle pressure is increased. The
torque converter clutch feature increases fuel econ-
omy and reduces the transmission fluid temperature.
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