Muwahhed Senior Member
Number of posts : 2786 Reputation : 0 Registration date : 20070528
 Subject: How To Crack a Master Lock Combination Sat Mar 22, 2008 1:34 pm  
 1) Get a Master Lock that you know the combination and if possible get another lock to test out if you doing it right.
2) First, we need to find the last number of the combination. To do this pull the “U” shaped thing away from the lock. It helps if its attached to something. (A Locker?). While pulling it out, start to rotate the dial from “0” so you know where to end later. You will notice that the lock will stick to a certain number. Now release the “U” for a second and then start to pull while you start to rotate again.
3) Next write down all the places the lock got stuck at while you were rotating it. There should be exactly 12 places if you did it right. One of these 12 numbers will be the last number of the combination.
4) Now we need to eliminate all of the numbers, but 1 to find the last. There are two types of places where the numbers you found got stuck at. First type is exactly on a number which means it won’t move left or right while pulling up the “U”. The second type is when the number you found was actually stuck between two numbers on the dial, and it would budge a little to the right or left.
5) Since we can determine, which of the 12 numbers were in between two numbers we can now eliminate them. There should have been 7 of those, which means there are only 5 left on you list.
6) Take a look at you list now and you should see that 4 of the 5 numbers left on you list have the same one’s place digit. (ex: 05, 15, 25, 35) These 4 numbers you found are fake and should be eliminated. This last number you have left should be the last number of you combination.
7) To find out the Master Lock Combination is easy now that you have the last digit. You now have 10 first digit possibilities and 10 second digit possibilities. This means you have to try out a maximum of 100 combinations. And don’t think that’s too many because this is much better than having to deal with 64,000 combinations. source 
