| Table 1: | Transmission Shifts Hard |
| Table 2: | Gears Clash When Shifting From One Gear to Another |
| Table 3: | Transmission is Noisy |
| Table 4: | Transmission Jumps Out of Gear |
| Table 5: | Transmission Will Shift Only Into One Gear |
| Table 6: | Transmission Is Locked In One Gear and Cannot Be Shifted Out |
Probable Causes | Correction | ||||||||
|---|---|---|---|---|---|---|---|---|---|
Shift shaft binding | Check for the following conditions:
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Clutch not releasing | Verify with the clutch spin down time test and correct. Refer Clutch Spin Down Time . | ||||||||
Shift shaft lever broken | Remove, disassemble, and replace the shift shaft lever. | ||||||||
Internal bind in the transmission caused by shift forks or synchronizer assemblies |
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Incorrect oil | Drain and refill the transmission. |
Probable Causes | Correction | ||||
|---|---|---|---|---|---|
Oil level is low or incorrect | Drain and fill the transmission. If the oil level is low, check for leaks and repair as necessary. | ||||
Clutch not releasing | Verify with the clutch spin down time test and correct. Refer to Clutch Spin Down Time . | ||||
Synchronizer assemblies worn or damaged |
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4th gear only - Mainshaft or input gear snap ring missing | Install the missing snap ring. |
Probable Causes | Correction | ||||
|---|---|---|---|---|---|
Lubrication level is low or incorrect oil | Drain and fill the transmission. If the oil level is low, check for leaks and repair as necessary. | ||||
Crankshaft pilot bearing/bushing worn | Replace the crankshaft pilot bearing/bushing. | ||||
Transmission to engine bolts loose | Check and correct the bolt torque as necessary. | ||||
Gear selection, mechanism, transmission gears, or bearing components worn or damaged |
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Cab floor to shift lever boot screws contacting transmission case | Replace screws with the correct length screws. | ||||
Transmission mounted fuel lines contacting the vehicle body | Tighten/attach the fuel line clips in order to prevent body contact. | ||||
Transmission shift lever to floor boot out of position, foam insulator missing/damaged, boot screws too long and contacting transmission | Correct/repair the shift boot and isolator installation. |
Probable Causes | Correction | ||||
|---|---|---|---|---|---|
4th gear only - Crankshaft pilot bearing/bushing worn | Replace the crankshaft pilot bearing/bushing. | ||||
Gear selection mechanism, shift forks, shift rail detent spring worn, broken, or damaged |
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Gear teeth back taper on sleeve, gear worn away or damaged |
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Excessive end play caused by worn thrust washers or output shaft gears |
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4th gear only - Mainshaft or input gear snap ring missing | Install the missing snap ring. | ||||
Transmission shift lever to cab floor boot out of position (convolutions trapped under boot retainer ring) pulling transmissions out of gear | Correctly install the boot retainer ring. |
Probable Causes | Correction | ||||
|---|---|---|---|---|---|
Gear selection mechanism or shift forks worn or damaged |
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Synchronizer sleeves or hubs damaged or worn |
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Probable Causes | Correction |
|---|---|
Shift rail worn or broken, shift fork bent, worn, or broken | Replace the worn or damaged components as necessary. |
Shift shaft lever worn or broken | Replace the worn or damaged components as necessary. |
Gear train components damaged | Replace the worn or damaged components as necessary. |
