Masterlock combination trick

[nekret]

After being thoroughly frustrated with my "new" design MasterLock (the ones that have a serial starting with 800) I decided to shim them open in an attempt to read the wheels through the hole in the lock body normally occupied by the shackle (shackle hole?).

Shining a flashlight inside the lock I could see the gates but it was still difficult to distinguish the false gates from the real ones on the last wheel, it was also difficult to distinguish the notch in the first wheel (the one used for rotating it when the lock is opened) from the gate. The solution ended up being a little out of Hollywood but I used a green laser (Don't forget the laser safety goggles!) to light up the internals by angling it away from the wheels so it would diffuse throughout the lock.

Now for the actual decoding! Using another MasterLock for reference I found that aligning each gate so that the gate was under the latch assembly with the edge of the gate just barely visible produced numbers 12-13 (depending on the angle you look at it) greater than the true combination. Subtracting 12-13 from each of the numbers found by this alignment method will yield the true combination or at least something close to it.

When you close the lock and try your combination it should open but in the event it doesn't try a couple of numbers adjacent to your combination. ie if you ended up with 22-28-9 try:
23-28-9
22-29-9
21-28-9
etc.

Once the lock opens continue probing the numbers around your new combination. Due to the size in the gates you should end up with a range of 2-4 numbers that work for each number in the combination. If you get a range of 3 numbers, choose the middle one, otherwise play with the two central ones and find out which one provides the least opening resistance.

For example, on my lock this method yielded the combination 35-1-22.
subtracting 13 gave a combination of 22-28-9. Trying the adjacent numbers for the first number yielded the following working first numbers:
22 23 24

So now using 23 as the first number I explore the adjacent numbers around the second number and find 26, 27, 28, and 29 all work. After using 28 and 29 a few times I conclude that 28 allows the lock to open with a little less resistance.

The last number, since it can be dialed directly you can pull up on the shackle while turning left and find the exact point where the gate is, on mine it was around 9.5. Closing the lock again and redialing the combination but this time dialing left to 7 and then pulling up on the shackle while turning right yields the other endpoint of the gate (around 8.25 on my lock. So the only real choice for the last number is 9.

Hope this helps anyone else who got annoyed with an 800 MasterLock combination padlock. Also this technique works for the other MasterLock combination padlocks but since it can take almost as long to do as running through the 64 combinations (once you found the last digit), may not be worth it.

[UWSDWF]

sounds like alot of work and expensive toys for a $5 lock

[Gordon Airporte]

sounds like alot of work and expensive toys for a $5 lock

It's the problem-solving challenge that's the thing. The price of the lock don't enter into it.

[nekret]

It was a little bit of work figuring the trick out but once done its a snap. As for the laser, I got mine at LuckyDuck for less than $40 And it's great for scaring the crows off adjacent buildings so it entertainment value as well .

I also probably wouldn't have bothered if I had only one of these but I got a box of 50 assorted masterlocks without their combinations for $20 (shipped) on eBay. I had 5 of the 800 series that were the only remaining obstacle to recovering all of them. Needless to say, it was a great feeling when they were all done.

[zeke79]

Great job on getting them all done .

[DrStu]

I found that the best way to see inside Master Combos without a flashlight is standing outside with the sun behind you.

[Wolfe]

thier is a easy way to open any master combo lock takes about 10ish mins to do it.Unforunetly im not sure i can post it because it runs along the lines of manipulation.(The dreaded ADVANCED TOPIC) n all that.

[nekret]

The ~10 minute trick I used on the rest of the locks ( having a serial number not starting with 800) but I was having a difficult time mastering the technique for the none-800 ones. As for the techniques for manipulating the masterlocks, it's become fairly public domain so I won't bother reposting them here however google pulls it up pretty fast.

[nekret]

*correction* I was having trouble with the locks with serial numbers starting with 800.