Not sure but this seems like the place for this one. My drivers side key lock all of a sudden yesterday quit working. It will not turn either way with the key I always use or a brand new one. Any ideas?? Thanks

 

Its possible that the shims in the door lock itself have worn out, get another lock and have it retumbled to your key and give it a try, I know I went through that problem with my truck, had to have it retumbled for it to work.

 

spray some wd-40 in the tumbler. that fixed mine once

 

I know this is an old thread, but I have some info that I hope will help someone else... I live on the coast where stuff corrodes quick, and I learned from a local locksmith that all he uses in doors with sitcky tumblers or other parts is a lubricant called Tri-flow. He says the oil in it is a good viscosity for lock tumblers, and the teflon keeps working after the oil has seeped off to parts downhill.

I was using this product on residential doors near the ocean and I knew how well it worked. The tailgate lock on my 98 F-150 had been sticky for years, and then my passenger door that I hadn't used in a long time was totally stuck... wouldn't turn at all. I tried tri-flow and they've both worked like new ever since... I now hit them with a little about once a year.