Troubleshooting Masterlock Hitch Pin Lock with Key that Won't Turn

Updated 11/05/2025 | Published 04/05/2023

Question:

I bought a lockable masterlock 5/8 hitch pin from you guys in 2013. I need to put a new ball hitch in but the lock is stuck - the key wont turn. I broke off one key in it already, fortunately I have the spare. I have tried WD-40 in the key hole and around with no luck. Any suggestions? This one seems like it will be real hard to get off if I cant unlock it

asked by: Tedd E

Expert Reply:

Sounds like your Masterlock locking hitch pin part # 2848DAT has some frozen tumblers. I would recommend using the straw of your WD40 can to direct it into the lock core as much as possible. Then use the good key to help get it into the lock core. To do this basically you'd want to repeatedly insert and remove the key to help work it in. Several applications of WD40 might be required.

expert reply by: Jameson C

Alan

7/8/2024

I have the same issue sort of. After wintering in my glove box my Masterlock hitch pin lock will go in the lock hold but the key will not release even though it seems to work when the pin isn't in. that is that is that the key goes in and goes to the correct position when released and can easily be removed. Any ideas?

Jameson C.

7/8/2024

@Alan It is probably going to be easiest to replace it but basically somehow there is corrosion in the lock which is preventing it from allowing itself to release. More and more WD40 could help.

Tim D.

11/5/2025

@JamesonC I called a locksmith, he cannot get it open so he ended up cutting it off with a Dremel in charge of me $250 for 15 minutes of work.

Jameson C.

11/5/2025

@TimD ahh man. Sorry to hear that.

Tim D.

11/5/2025

Very curious of the outcome, I’m having the same problem and I’m supposed to pick up a U-Haul in one hour and cannot get the lock to to open. No amount of WD-40 seems to work.