Jeep 1996 Grand Cherokee Service Manual - page 1166
CONDITION
POSSIBLE CAUSES
CORRECTION
11. Hydraulic Pressure Low.
11. Pressure test transmission to
determine cause.
12. Valve Body Valve Stuck.
12. Repair stuck 3-4 shift valve, 3-4
timing valve.
13. O/D Piston Incorrect Spacer.
13. Remove unit, check end play and
install correct spacer.
14. Overdrive Piston Seal Failure.
14. Replace both seals.
15. O/D Check Valve/Orifice Failed.
15. Check for free movement and secure
assembly (in piston retainer). Check ball
bleed orifice.
SLIPS IN OVERDRIVE
FOURTH GEAR
1. Fluid Level Low.
1. Add fluid and check for leaks.
2. Overdrive Clutch Pack Worn.
2. Remove overdrive unit and rebuild
clutch pack.
3. Overdrive Piston Retainer Bleed
Orifice Blown Out.
3. Disassemble transmission, remove
retainer and replace orifice.
4. Overdrive Piston or Seal Malfunction.
4. Remove overdrive unit. Replace seals
if worn. Replace piston if damaged. If
piston retainer is damaged, remove and
disassemble the transmission.
5. 3-4 Shift Valve, Timing Valve or
Accumulator Malfunction.
5. Remove and overhaul valve body.
Replace accumulator seals. Make sure
all valves operate freely in bores and do
not bind or stick. Make sure valve body
screws are correctly tightened and
separator plates are properly positioned.
6. Overdrive Unit Thrust Bearing Failure.
6. Disassemble overdrive unit and
replace thrust bearing (NO. 1 thrust
bearing is between overdrive piston and
clutch hub; NO. 2 thrust bearing is
between the planetary gear and the
direct clutch spring plate; NO. 3 thrust
bearing is between overrunning clutch
hub and output shaft).
7. O/D Check Valve/Bleed Orifice
Failure.
7. Check for function/secure orifice insert
in O/D piston retainer.
DELAYED 3-4 UPSHIFT
(SLOW TO ENGAGE)
1. Fluid Level Low.
1. Add fluid and check for leaks.
2. Throttle Valve Cable Misadjusted.
2. Adjust throttle valve cable.
3. Overdrive Clutch Pack Worn/Burnt.
3. Remove unit and rebuild clutch pack.
4. TPS Faulty.
4. Test with DRB scan tool and replace
TPS.
5. Overdrive Clutch Bleed Orifice
Plugged.
5. Disassemble transmission and replace
orifice.
6. Overdrive Solenoid or Wiring
Shorted/Open.
6. Test solenoid and check wiring for
loose/corroded connections or shorts/
grounds. Replace solenoid if faulty and
repair wiring if necessary.
ZJ
TRANSMISSION AND TRANSFER CASE
21 - 27
DIAGNOSIS AND TESTING (Continued)