Review on CURT 23556 Channel Mount Lock by Eric Trask

My rating has been downgraded from 5 stars to 3 stars, now to 1 star. I bought this in December 2013 along with a Curt hitch. The lock at the Kanalstift was closed until December 2015. I don't change size often so it hasn't been used regularly. Bought them again in spring 2016 and as of now (March 2019) both locks are locked so tightly that they don't turn. I had to soak them in a PB Blaster to get even one of these. I had to grind the other one. I know New York State has harsh salt/snow/cold/heat conditions, but a 3 year lifespan for such an expensive lock set is just insane. Switched to another brand of Tractor Supply as I needed to flip the ball on a Curt hitch. I kept the cap on them. I live in the North East and drive a trailer in winter so salt plays a big part. I remove the hitch from the truck when not in use. It rotated about 1/4 turn (the toggle switch in the lock was free and rotating) but didn't disengage the deadbolts. For $50 I was hoping to get a longer lifespan. On the plus side, it took me a few minutes to cut the pin off with a cutting wheel.