Simple question for ya all. I have a '73 teener and everytime I attempt to lock or unlock the doors with my key I feel like the damn thing will break off! Tried a silicone spray but they locks are still so stiff! Any advice?
evan

I had two sticky door locks, and I just took the door panels off, carefully removed the vapor barrier, and shot some wd40 at the mechanism. I also lubed any moving part I could easily reach. Now, the door locks work like new (or at least what I assume new would feel like - my car was built 10 years before I was born)

Over the years locks can collect dirt from the wrong use of lubercants. Most locksmiths will tell you to use graphite only on a locks tumblers.

You might have to take them out and clean them to get the crud off for them to work right. I would use a light spray of lithium grease on any of the other parts (after cleaning). It will protect, lube and waterpruf the outside parts and use graphite on the tumblers only.

Mine were so hosed up with crud I had to pull the mechanism out and soak scrub soak some more before I could get them working GUD.
the tumblers "can" be taken out and cleaned But be careful because there are lots of "jesus" parts in there. Like jesus what was that and where did it go.

It is best to put the key in the lock, take that little cam piece off the back side than pull the cylinder out of the housing. DO NOT take the key out of the cylinder once the cylinder is out of the handle housing or the jesus pieces will fall out and you'll have a puzzle on your hands trying to get them back in the right order.

Soak it to loosen the crap up.