I know this is an old thread and I stumbled on it while looking for something else. The alternative I used to replace the key may have been covered already but for what it is worth here is my story.
I discovered shortly after buying my 2002 F-250 that it did not have the key to lower the spare tire. There was only one local dealer that had a full set of keys and they were in the middle of a labour disruption. They told me to contact McGard, the manufacturer of the locks, directly. I called McGard and the people there said to take a small piece of styrofoam from a coffee cup and glue it to a piece of dowel or rod and push it into the tube and up against the lock. This gives you an impression of the lock. I then mailed it to McGard and they sent me a new key. The whole process took about a week and a half before I got the key and that was shipping it across the border to me in Canada as well. Can't remember exactly what the cost was but it was not outrageous.
Of course this does you no good if you are sitting at the side of the road and need to get the spare down in a hurry but it is another source for the key.
I guess I'm the only one that drops the spare occasionally to clean out all the crap that gets flung up on the wheel, inspect the tire, fill it with air, lube the cable and even paint the wheel if it needs it.
DKF, you are the reason people steal spare tires. They are hoping to find yours!!
I bought my 2005 F250 a month ago and the spare tire key was not in the truck. I took it to the Ford dealership and went through their keys and dropped the tire. Went home and disassembled the tire holder and removed the key. Now I can just use the extension.. If someone wants my spare, they are gonna get it.
This forum is great. The '03 I just bought didn't come with a spare. So I picked one up and went to mount it under the truck. Turns out the truck didn't come with the key for the spare either. So I jumped on here and found out everything I needed to do to address the situation. 10 minutes later, I had the spare mounted under the truck. Awesome. Sure, it's not locked. But it wasn't exactly locked laying in the bed, either. And, I can just take the lock down to the local ford dealer and get a key if I ever feel the need for more security.