ASE G1 Auto Maintenance and Light RepairManual Drive Train and AxlesEasy
A technician is inspecting a vehicle's manual transmission that has a persistent leak. They have identified that the leak is coming from the output shaft area where it connects to the driveshaft. Which component is MOST likely responsible for preventing this leak?
- AShift shaft seal
- BInput shaft seal
- CRear main seal
- DOutput shaft seal
Show answer & explanationAnswer & explanation
Correct answer: D. Output shaft seal
The output shaft seal is specifically designed to prevent transmission fluid from leaking where the output shaft exits the transmission case and connects to the driveshaft.
Why the other options are wrong
- A. The shift shaft seal prevents leaks around the shift linkage shaft(s) that enter the transmission case.
- B. The input shaft seal prevents leaks where the input shaft enters the transmission from the engine.
- C. The rear main seal is on the engine crankshaft, preventing engine oil leaks, not transmission fluid.
Transmission Seals
Various seals within a manual transmission prevent fluid leakage from different points where shafts or linkages enter or exit the transmission case.
- Input shaft seal: at engine side.
- Output shaft seal: at driveshaft side.
- Shift shaft seals: around shift mechanism.
- Prevent fluid loss and contamination.
Memory trick: Output shaft leak? Output seal's the weak link.