Examkin

Question

Difficulty: EasyDriveshafts and Differentials

In a rear-wheel-drive vehicle, the driveshaft transmits engine torque lengthwise along the vehicle chassis. What is the primary purpose of the ring and pinion gear set located inside the rear axle assembly?

  1. A
    To allow the driveshaft to expand and contract in length during suspension travel
  2. To change the rotational power direction by 90 degrees and provide gear reductionAnswer
  3. C
    To allow the left and right drive wheels to rotate at different speeds while turning
  4. D
    To absorb variations in driveshaft operating angles caused by rear axle movement

Answer

To change the rotational power direction by 90 degrees and provide gear reduction
In a longitudinal rear-wheel-drive powertrain, engine torque enters the rear axle parallel to the vehicle length. The drive pinion gear meshes with the ring gear at a right angle, converting this longitudinal rotation into transverse rotation to turn the left and right drive axles, while the gear ratio between them provides final torque multiplication.

Step-by-Step Solution

1
Identify the orientation of driveline torque entering the axle assembly.
Rotational torque travels longitudinally (front-to-back) along the driveshaft to the drive pinion gear.
The engine and transmission output shaft rotate along the vehicle's centerline.
2
Determine the mechanical interaction between the drive pinion and the ring gear.
The small drive pinion turns the larger ring gear, transferring rotational motion 90 degrees toward the transverse axle shafts while multiplying torque through gear reduction.
The drive wheels require transverse rotation and mechanical advantage to propel the vehicle.

Key Concept

Ring and Pinion Gear Function
Estimated Time:45s
Rate this question

Topics

Driveshafts and Differentials

More questions from this topic