AUSV 2520 – Clutches, Bands, and One Way Devices

From WeberAuto.

This video is intended for students in the online AUSV 2520 Automatic Transmissions class at Weber State University in Ogden, Utah. This class is normally taught face-to-face, but due to the COVID-19 Pandemic, I am attempting to offer the class material online. Suggested quiz questions are shown below the video timeline. You should have watched the following Planetary Gear Set video first

This video covers basic operation and function of clutches, bands, and one-way devices in automatic transmissions.

Review of planetary gear set operation at 0:03
Bands on an old Chrysler transmission at 1:53
Clutch packs at 5:16
Valve Bodies and Solenoids at 6:03
Clutch pack details at 7:36
Clutch Backing plate at 8:53
Clutch fiber disc at 9:28
Clutch steel plate at 10:02
Clutch Apply plate at 10:40
Clutch pack compared to a sandwich at 10:55
Clutch apply piston and return spring operation at 10:05
The number of clutch fiber discs versus the clutch plate diameter at 18:00
Clutch disc separation springs at 20:00
Waved steel plate for shift cushioning at 21:53
MUST-SEE: Air Checking Clutch Packs at 23:30
One-Way Devices at 24:42
Sprag clutch at 25:04
Why do we use one-way devices? at 27:23
Roller Clutch at 30:04
Ratcheting Clutch at 32:40

– What is the purpose of the Bands in the old Chrysler automatic transmission shown in the video?
– What are the four main components of a clutch pack?
– What is the function of the clutch backing plate?
– What is the function of the clutch steel disc plate?
– What is the function of the clutch fiber disc plate?
– What is the function of the clutch apply plate?
– What is the function of a clutch piston?
– What is the function of the clutch piston return springs?
– What forces make the clutch piston move?
– What is the purpose of a clutch wavy plate?
– Why do you think air checking clutch pistons is a good idea?
– Select one: How far did the clutch piston move in the air-checking portion of the video? A tiny amount, a moderate amount, a large amount, or it varied with each clutch pack.
– The amount of clutch piston movement indicates the clutch pack clearance when the clutch pack is released. Is clutch pack clearance adjustable?
– What is the purpose of one-way devices?
– Tell me one thing you learned or found interesting in this assignment?

Weber State University (WSU) – Automotive Technology Department – Automatic Transmission Lab. A technical discussion of Clutches, Bands, and One Way Devices in an automatic transmission.

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This video was created and edited by John D. Kelly at WSU. For a full biography, see

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