I have a 98 Jeep Wrangler and a 2006 Wrangler. After looking at the internals of the 98 version, I'm able to pick it easily with a tension wrench and a single sided figure 8. The wafers are "straight" on both sides so tension applied in either direction locks up the cylinder. In this version, I can just go "1, 2, 3, 4 up " then "1, 2, 3 down" with very little tactile feedback required. That is, I can keep the turning force constant and don't need to feel the cylinder turn slightly with every wafer.
http://faq.f650.com/FAQs/Photos/MiscPho ... wafers.jpg
With the 2006 version, the wafers are slightly rounded in the unlock direction making it more difficult to push the wafers against the cylinder and requiring a lot more force on the tension wrench and pick.
A couple of questions:
1. Is there a technique to working with rounded edge wafers that doesn't involve all the additional turning force?
About the only thing I can think of is moving each of the wafers "through" the cylinder initially to expose the straight edge of the wafer, let off on the tension and move them in reverse more easily.
2. I only have two locks to base observations on, but in both of them, 6 of the 7 wafers always move easily into place but one wafer is more difficult regardless of the pick used. The difficult wafer is in the same position order in both. Just a function of the lock dimensions?
3. Is the "lock code" for each of the keys related somehow to the position and value of the wafers or is it just a lookup table? For example, in both locks there are only 4 distinct wafers, marked 1-4 on the bottom of each wafer. So for 7 wafer (4 in one direction,3 in the other), you get some number ( 4-1-1-2-3-2-1 for example). Given the lock code, can you derive the wafer value/order and vice versa?
I came up with a few algorithms that work for both the locks but involve some fairly complicated functions that don't seem like they'd be used by a mass assembly.
Thanks!