NAPA - National Automotive Parts Association Certified Mechanic Automatic Transmission Systems Questions and Answers

Question 1

A vehicle with an automatic transmission is brought into the shop with the complaint of delayed engagement and the engine RPM flaring up during shifts. The technician confirms the fluid level is correct and the fluid is not burnt. Which of the following is the MOST likely cause of these symptoms?

Accepted Answer

Worn clutch packs or bands

Answer

When clutch packs or bands inside an automatic transmission are worn, they cannot create the necessary friction to engage gears properly. This results in the engine speed increasing without a corresponding increase in vehicle speed (flaring) and a noticeable delay before the gear engages.

Question 2

What is the primary function of the torque converter's lock-up clutch in a modern automatic transmission?

Accepted Answer

To create a direct mechanical link between the engine and transmission at cruising speeds

Answer

The lock-up clutch engages at cruising speeds to eliminate the hydraulic slippage inherent in the torque converter. This creates a 1:1 mechanical connection between the engine's crankshaft and the transmission's input shaft, which improves fuel efficiency and reduces heat buildup.

Question 3

The component in an automatic transmission that acts as the hydraulic control center, directing fluid pressure to apply clutches and bands, is known as the:

Accepted Answer

Valve body

Answer

The valve body is an intricate maze of channels, valves, and solenoids that directs high-pressure automatic transmission fluid to the correct clutch packs or bands at the precise moment to execute a gear shift.

Question 4

A customer complains that their vehicle feels sluggish, shifts erratically, and the check engine light is on. A scan tool reveals a trouble code for a shift solenoid circuit malfunction. This indicates a likely problem with a(n):

Accepted Answer

Electro-hydraulic valve that controls fluid flow

Answer

A transmission solenoid is an electro-hydraulic valve that controls the flow of transmission fluid as directed by the Transmission Control Module (TCM). A circuit malfunction code points directly to an issue with the solenoid itself or its wiring, leading to symptoms like erratic shifting, harsh engagement, or the vehicle entering 'limp mode'.

Question 5

Which of the following BEST describes the function of a planetary gear set in an automatic transmission?

Accepted Answer

It uses a sun gear, planet gears, and a ring gear to create various gear ratios.

Answer

Planetary gear sets are the core mechanical components that provide different gear ratios (e.g., reverse, neutral, forward reduction, direct drive, overdrive). By holding or driving different members of the set (sun gear, planet carrier, or ring gear), the transmission can achieve the various ratios needed for driving.

NAPA - National Automotive Parts Association Certified Mechanic Practice Test

NAPA - National Automotive Parts Association Certified Mechanic Practice Test

NAPA - National Automotive Parts Association Certified Mechanic Automatic Transmission Systems Questions and Answers