Trailer Coupler Lock

[Daniel Elias]

Which coupler lock is best for a 2017 Z21? I'm having a hard time finding one that fits. I tried the straight 3.5" bar lock from master lock and it broke in half trailering the boat the first trip I used it. Standard locks don't seem to fit...

[OldTimer57]

Forget those long-pin locks. Had exactly the same result. Three times. The pin is weak thanks to the groves machined into it to capture the lock. How they get bent I do not quite see. I am using a common master lock type lock, one that fits through the hole (I have a UFP brake system, A-60 actuator). It works just fine. About the only downside is that the locking loop is exposed for heavy-duty bolt cutter access. Master also makes a lock where the loop is shaped like an L rather than a U. I am using this at the moment, but it can be aggravating to put it on until you get used to it.

[Terrieb24]

Have had the same problem. They break due to the action of the tongue with the trailer brakes. I run down the road with the lock off....only lock it up over night. Oldtimer57....can you by chance get me a part number or pic of the master lock you are using?

[OldTimer57]

I will do so. Bought it at Wal-mart in the towing section. The lock part is rough brass, the loop is stainless it appears. More in a bit.

[moetorola]

Had mine bend too!

If you don't swivel the lock up and push the lock all the way in or tight it will be fine. In other words let the lock hang down.

Pushing it in all the way will not let the tongue slide, to activate the surge brakes. The toung needs to be able to move back and forth. The straight pin is bent because of the force of the trailer catching on the lock.

Here you can see the silver hitch moving in and out under braking, I have a locking straight bar in.

[BD1]

Master Lock 527D