ASE A3 Manual Drive Train and Axles
11. A manual transmission makes a growling sound that increases with engine speed. The sound is heard toward the front of the transmission with the clutch pedal out and the clutch fully engaged. Which of the following is causing this noise?
- A. Pilot bearing
- B. Output shaft bearing
- C. Warped flywheel
- D. Input shaft bearing
Answer A is wrong. A faulty pilot bearing is loudest when the clutch pedal is depressed completely and the clutch is fully disengaged. This is because the input shaft has slowed while the crankshaft is still spinning at engine speed.
Answer B is wrong. A faulty output shaft bearing is heard toward the back of the transmission.
Answer C is wrong. Worn bearings make a growling sound.
Answer D is correct. A faulty front bearing is loudest when the clutch is fully engaged and the input shaft is spinning at engine speeds.
12. Which type of bearing typically requires a preload?
- A. Ball Bearing
- B. Thrust Bearing
- C. Tapered Roller Bearing
- D. Needle Bearing
Answer A is wrong. Ball bearings are similar to roller bearings. The cages hold balls instead of rollers and are capable of handling heavy radial loads.
Answer B is wrong. Thrust washers control endplay.
Answer C is correct. Tapered roller bearings require a preload.
Answer D is wrong. Needle bearings or Torrington bearings are used to reduce friction between two rotating parts.
13. A transfer case makes a popping sound in 4WD, only when accelerating from a stop. Which of the following is causing this sound?
- A. The output shaft assembly.
- B. The shift motor.
- C. The chain.
- D. A clogged vent.
Answer A is wrong. It is unlikely the output shaft would cause a popping sound.
Answer B is wrong. A bad shift motor will prevent 4WD engagement.
Answer C is correct. A stretched chain can make a popping or rattling sound. It can also damage the case.
Answer D is wrong. A clogged vent will cause external fluid leaks.
14. A vehicle has an excessive vibration at highway speeds. Technician A says companion flange runout will result in this vibration. Technician B says this could be caused by driveshaft runout. Who is correct?
- A. Technician A
- B. Technician B
- C. Both A and B
- D. Neither A or B
Answer A is wrong. Both answers are correct. Companion flange runout will cause a vibration that increases with vehicle speed. This is especially noticeable at highway speeds.
Answer B is wrong. Driveshaft runout causes a vibration while driving at highway speeds.
Answer C is correct. Both technicians are correct.
Answer D is wrong. Both technicians are correct.
15. The best tool for checking ring gear runout is a:
- A. Bore gauge.
- B. Digital micrometer.
- C. Dial indicator.
- D. Straightedge and feeler gauge.