Vehicle Systems: Coupling Systems

The primary function of the coupling system in a tractor-trailer is to connect the tractor to the trailer, the power to the payload. The two key components in the coupling system are the fifth wheel and the trailer kingpin. Coupling the tractor to the trailer through a single 2-inch kingpin is one of the most critical areas of tractor/semitrailer operation.

Tip: These videos are not supported in Internet Explorer. Try any other internet browser; Chrome, Firefox, iphone, Android, Commodore, anything other than IE.


This is a sample course from our training library. You're welcome to view the course for personal use. Drivers of member fleets will receive a certificate after completing the online course. Please sign into your account to take an assignment. A certificate will be delivered electronically to your driver qualification file.

First Transit
Shamrock Foods Driver

Customer Comments

Dennis Atencio - Director of Safety
Apex Transportation

Bob Bowman - Director, Safety & H.R.
Alpine Lumber Company

Tim Long - Director of Safety
Epes Transport System

Safety as a Service
How it Works
Contact Us
Train Drivers
Find Drivers
Hire Drivers
Sign Up

© 2010-2016. Safety as a Service. A product of CDL College.

7170 Dahlia St. Commerce City, CO 80022. 303-367-1030