Tech & Installation
With the lock unlocked and pin dropped, slide the frame onto your stamped steel trailer coupler
Raise the black pin into the couplers ball socket
Push the key and key cylinder into the lock and turn the key 90° to lock.
The latch handle of the coupler must be in the locked position. Some latch handles need to be pushed back slightly to accommodate the lock sliding into the correct position.
Not all couplers are the same
We have found that some 2-5/16" couplers will fit a 2" lock. We base our sizes off of coupler flange with. Max width for 2-5/16 is 4-3/8 wide. For the 2" lock, max flange width is 3-5/8" wide. Measurement is based off the flange width on the bottom of the coupler.
What is a stamped steel coupler?
Stamped steel coupler
Stamped steel couplers are formed from one piece of steel. These couplers will have a flange that flares out from the bottom of the coupler to make a lip around the base. Madlock utilizes that flange to keep your trailer safe and secure.
Some couplers are made from different materials such as cast steel and have a different design. Most cast couplers do not have a flanged lip at the bottom. If you have a cast coupler Madlock will not currently fit your application.