Exam – (Attempt 1 Passed) Expert Strategies,
Review of Key Practice Questions and Verified
Detailed Answers; for Guaranteed Success
This Set Review the most commonly tested concepts and answers for the Manual
Transmission/Transaxle Principles Final Exam. Mastering these core principles
ensures you are prepared for automotive drivetrain quizzes.
Core Concepts & Principles
• Gear Ratio Calculation: Mechanical advantage is determined by dividing
the number of teeth on the driven gear by the number of teeth on the
driving gear. For example, a 20-tooth driving gear and a 40-tooth driven
gear provide a 2:1 ratio.
• Speed & Torque Relationship: Torque and speed have an inverse
relationship. As output torque increases, output speed decreases.
• Direct Drive: In direct drive (usually 4th gear in a 5-speed manual), the
gear ratio is \(1:1\). Power flows straight from the input shaft to the output
shaft, bypassing the countershaft.
• Final Drive Assembly: This assembly reduces the overall gear ratio and
changes the direction of power delivery to the drive wheels (typically
\(90^{\circ }\)).
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, • Synchronizer Function: Synchronizers match the speed of the gear with
the speed of the shaft to allow for smooth, clash-free gear changes. The hub
is splined directly to the shaft
• Reverse Gear: A reverse idler gear is used to reverse the rotational
direction of the output shaft.
• Clutch Safety Switch: This switch prevents the engine from starting
unless the clutch pedal is fully depressed.
Q1. Which of the following is NOT affected by the gear ratio of the
final drive assembly? [Multiple Choice]
A) The transmission shift patterns
B) vehicle top speed at a given engine RPM
C) axle torque delivered to the wheels
D) engine RPM at cruising speed
Answer: The transmission shift patterns
Explanation: Final drive gear ratio affects vehicle acceleration, top speed at a given
engine RPM, and engine RPM at cruising speeds because it changes the torque
multiplication and wheel speed per engine revolution. Transmission shift patterns are
determined by gearbox design (gear spacing and selector layout), not by the final drive
ratio, so they are unaffected. Distractors: "vehicle top speed at a given engine RPM" is
influenced because a taller final drive yields higher wheel speed per engine RPM; "axle
torque delivered to the wheels" is directly affected by final drive torque multiplication;
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, "engine RPM at cruising speed" changes with final drive ratio because overall gearing
determines RPM for a given road speed.
Q2. Explain why two gears in mesh tend to push each other apart
when the vehicle is accelerating. [Short Answer]
Answer: When torque is transmitted through meshing teeth, contact forces
at the tooth faces produce a separating or thrust effect on the gear centers,
so two gears tend to push each other apart under acceleration. Designers
counter this with bearings, thrust washers, or proper support.
Explanation: Transmitting torque at the tooth contact creates reaction forces that have
components that push the gears away from each other; this is why supports and
bearings are required. A complete answer explains the force outcome and notes that
support components are used to resist that separation.
Q3. Technician A says synchronizers are used to match the clutch and
input shaft speeds to provide easier gear changes. Technician B says a
synchronizer matches gear speed with shaft speed. Who is correct?
[Multiple Choice]
A) Technician B
B) Technician A
C) Both technicians
D) Neither technician
Answer: Technician B
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