Time Lag Test: Notes
NOTE:
Time lag test checks overdrive clutch, forward clutch, rear clutch and first-reverse brake. Condition is indicated by time required for component engagement with engine idling. Engagement time is measured in Drive and Reverse.
- Ensure transmission fluid level is correct and transmission is at normal operating temperature. Apply parking brake and ensure A/C is off.
- On Comanche and Cherokee 4WD models, shift transfer case into 2H (2WD high position). On Grand Cherokee models with NP249 transfer case, shift transfer case into 4H (4WD high position) and with all other transfer cases, shift transfer case into 2H (2WD high position).
- Start engine and ensure engine idle speed is within specification. Refer to emission decal in engine compartment. Engine idle speed must be correct to ensure accurate test results.
- Shift transmission into Neutral and set stop watch. During following test steps, start stop watch as soon as shift lever reaches "D" (Drive) and Reverse detents.
- Shift transmission into "D" (Drive) and record time it takes for engagement. Repeat procedure at least 2 times. Reset stop watch and shift transmission to Neutral.
- Shift transmission into Reverse and record time it takes for engagement. Repeat procedure at least 2 times.
- Engagement time in "D" (Drive) should be a maximum of 1.2 seconds and Reverse should be a maximum of 1.5 seconds.
NOTE:
Use the following symptoms for trouble shooting results of time lag test.