If the transmission jumps out of gear during deceleration, inspect the components that may allow for the gears or shafts to tip. If the gears or shafts tip, the synchronizer sleeve can disengage from the selector teeth on the speed gear. If the transmission jumps out of gear during acceleration, inspect the components that may not allow full engagement of the synchronizer sleeve to the selector teeth on the speed gear. Insufficient engagement of the selector teeth under torque may cause the transmission to jump out of gear.
The numbers below refer to the step numbers on the diagnostic table.
A static shift test is performed by shifting into all gear positions with the engine not operating. While performing the test, slowly move the shift lever. Feel for proper movement of the shift lever and transmission internal shift components.
A dynamic shift test is performed by shifting into all gear positions with the engine operating. Test for the correct mesh of the synchronizers sleeve and the speed gear selector teeth. Move the shift lever, and feel for the synchronizer sleeve to release form the gear, and then let up on the clutch pedal. Depress the clutch pedal and move the shift lever to engage the gear again, to ensure full travel of the shift components.
This step inspects for worn or damaged transmission or engine mounts. Loose mounts may cause a shock on the transmission, allowing for gear disengagement.
This step inspects for the misalignment of the clutch to transmission. Misalignment may put a bind on the input shaft, allowing for the input shaft or the mainshaft to tip.
This step inspects the pilot bearing and the pilot bearing journal on the input shaft. A worn pilot bearing or input shaft may allow the input shaft to tip, causing gear disengagement.
Step | Action | Yes | No | ||||||||||||||||||||
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DEFINITION: Gear disengagement occurs during acceleration or deceleration. | |||||||||||||||||||||||
1 | Did you review the Symptoms - Manual Transmission and perform the necessary inspections? | Go to Step 2 | |||||||||||||||||||||
Did the transmission shift completely into all gears? | Go to Step 4 | Go to Step 3 | |||||||||||||||||||||
3 | Remove the shift control housing and inspect for worn or faulty components. Refer to Transmission Disassemble and Transmission Assemble. Did you find and repair the condition? | Go to Step 10 | Go to Step 4 | ||||||||||||||||||||
Did the transmission shift completely into all gears? | Go to Step 5 | Go to Step 8 | |||||||||||||||||||||
Inspect the engine and/or transmission mounts. Refer to Propeller Shaft, Differential, and Driveline Support Replacement. Did you find and repair the condition? | Go to Step 10 | Go to Step 6 | |||||||||||||||||||||
Inspect the clutch housing for loose bolts or misalignment. Are there any loose bolts or misalignment? | Go to Step 7 | Go to Step 8 | |||||||||||||||||||||
7 |
Did you find and repair the condition? | Go to Step 10 | Go to Step 8 | ||||||||||||||||||||
Did you find and repair the condition? | Go to Step 10 | Go to Step 9 | |||||||||||||||||||||
9 |
Did you find and repair the condition? | Go to Step 10 | Go to Diagnostic Aids | ||||||||||||||||||||
10 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 1 |