Jeep Wrangler 1997, Руководство пользователя

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(d) NEUTRAL position—Engine running and
brakes applied, apply forward force on center of
shift handle. Transmission shall not be able to shift
from neutral to reverse.
THROTTLE VALVE CABLE
Transmission throttle valve cable adjustment is
extremely important to proper operation. This adjust-
ment positions the throttle valve, which controls shift
speed, quality, and part-throttle downshift sensitivity.
If cable setting is too loose, early shifts and slip-
page between shifts may occur. If the setting is too
tight, shifts may be delayed and part throttle down-
shifts may be very sensitive. Refer to the Adjust-
ments section for adjustment procedure.
ROAD TESTING
Before road testing, be sure the fluid level and con-
trol cable adjustments have been checked and
adjusted if necessary. Verify that diagnostic trouble
codes have been resolved.
Observe engine performance during the road test.
A poorly tuned engine will not allow accurate analy-
sis of transmission operation.
Operate the transmission in all gear ranges. Check
for shift variations and engine flare which indicates
slippage. Note if shifts are harsh, spongy, delayed,
early, or if part throttle downshifts are sensitive.
Slippage indicated by engine flare, usually means
clutch, band or overrunning clutch problems. If the
condition is advanced, an overhaul will be necessary
to restore normal operation.
A slipping clutch or band can often be determined
by comparing which internal units are applied in the
various gear ranges. The Clutch and Band Applica-
tion chart provides a basis for analyzing road test
results.
ANALYZING ROAD TEST
Refer to the Clutch and Band Application chart
and note which elements are in use in the various
gear ranges.
Verify that the rear clutch is applied in all forward
ranges (D, 2, 1). The transmission overrunning clutch
is applied in first gear (D, 2 and 1 ranges) only. The
rear band is applied in 1 and R range only.
Verify that the overdrive clutch is applied only in
fourth gear and the overdrive direct clutch and over-
running clutch are applied in all ranges except fourth
gear. For example: If slippage occurs in first gear in
D and 2 range but not in 1 range, the transmission
overrunning clutch is faulty. Similarly, if slippage
occurs in any two forward gears, the rear clutch is
slipping.
Applying the same method of analysis, verify that
the front and rear clutches are applied simulta-
neously only in D range third gear. If the transmis-
sion slips in third gear, either the front clutch or the
rear clutch is slipping.
If slippage occurs during the third gear and the
direct clutch were to fail, the transmission would lose
both reverse gear and overrun braking in 2 position
(manual second gear). If the transmission slips in
any other forward gears, the transmission rear clutch
is probably slipping.
This process of elimination can be used to identify
a slipping unit and check operation. Proper use of
the Clutch and Band Application Chart is the key.
Although road test analysis will help determine the
slipping unit, the actual cause of a malfunction usu-
ally cannot be determined until hydraulic and air
pressure tests are performed. Practically any condi-
tion can be caused by leaking hydraulic circuits or
sticking valves.
Unless a malfunction is obvious, such as no drive
in D range first gear, do not disassemble the trans-
mission. Perform the hydraulic and air pressure tests
to help determine the probable cause.
HYDRAULIC PRESSURE TEST
Hydraulic test pressures range from a low of one
psi (6.895 kPa) governor pressure, to 300 psi (2068
kPa) at the rear servo pressure port in reverse.
An accurate tachometer and two test gauges are
required for the pressure test. Test Gauge C-3292
has a 100 psi range and is used at the accumulator,
governor, and front servo pressure ports. Test Gauge
C-3293-SP has a 300 psi range and is used at the
rear servo port and overdrive test ports where pres-
sures are higher. In cases where two test gauges are
Fig. 5 Clutch And Band Application
21 - 82 TRANSMISSION AND TRANSFER CASE
TJ
DIAGNOSIS AND TESTING (Continued)