I'm currently trying to unlock my bike that has been sitting on my porch for a while, the key works and turns, and I can hear the lock engaging/disengaging, however I cannot get the shackle to come out. I think their might be dust/sand stuck in the mechanism however I'm not sure how to get it off now to check.
I've read about this problem in reviews of OnGuard locks on Amazon, so it's likely a design flaw with rust as a possible culprit. I haven't read about any solutions to it, beyond renting a power grinder to cut the lock off so you can buy a better one next time. That was one of the reasons I chose not to buy OnGuard, the other reason is one key fron an OnGuard lock fits multiple locks, which would allow a bike thief to walk around with a large key ring trying several keys until one of them works (the cheaper Kryptonite locks also have this problem).– Robin AsheJul 3, 2012 at 22:25
I'd try first putting it in what you believe to be the unlocked position, then applying a hammer in such a way as to knock the pieces apart. Failing that, an angle grinder. (If there's a Harbor Freight nearby you can probably buy one for under $20.)– Daniel R HicksJul 4, 2012 at 1:28
Related: U-lock stuck on a bike– Goodbye Stack ExchangeJul 4, 2012 at 3:57
Get some "Creep" or other penetrating oil (ask at Home Depot or Lowes and they'll point you right to it). This is similar to WD-40 but it foams a bit and seeps in everywhere. Apply liberally both at both ends where the U plugs into the bar as well as where the key fits in (key may turn without the tumblers moving completely).
This will likely loosen things up...a bit of patience and a bit of trying to move the parts around will usually work wonders.
If this fails, apply some more "creep" and use a persuader (hammer, etc).
If that fails, you're going to need a hacksaw and a couple of blades.
Good luck! Note: This is karma's way of telling you that your bike likes to live indoors when it's not being ridden :-)
The lubricant to use is Tri-Flow Teflon-bearing spray lube. Jul 4, 2012 at 4:20
2I like teflon for once parts are moving, but to get into the rusted up crevices, creep is the stuff. trizolube.com/TRIZOL_WEBSITE/CREEP.html or amazon.com/Blaster-16-PB-Penetrating-Catalyst-oz/dp/B000I2079E/… both will do a lot to get things unstuck. Jul 4, 2012 at 4:46
Instead of a hacksaw, better use an angle grinder, if you have one. Opens any lock within seconds... Sep 30, 2019 at 1:36
This just happened to me … WD40!!! spray it right inside the lock and turn the whole unit over and spray it in the parts that go into the lock itself. Wait a few minutes and do it again…. keep trying the lock, turn it upside down so the WD40 gets inside of everything. Wait an hour and try again, mine finally unlocked, Yahoo!!! good luck !