Test Description

The numbers below refer to the step numbers on the diagnostic table. See Fig 1.

1. 2
   
   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.
2. 4
   
   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.
3. 5
   
   This step inspects for worn or damaged transmission or engine mounts. Loose mounts may cause a shock on the transmission allowing for gear disengagement.
4. 6
   
   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.
5. 8
   
   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.
Fig 1: Transmission Jumps Out of Gear Diagnostic Table (Steps 1-10)
Courtesy of GENERAL MOTORS CORP.