driver side door lock sticks hard to unlock, these are the original locks, should i replace them or is there a way to
clean them so the key will turn freely when unlocking the door...i have tried wd40 and graphite neither worked very long..

 

Is it the lock cylinder that is stiff? Or the lock on the latch itself??

My favorite method of freeing them up is PB Blaster. Get the can with the little plastic tube, stick the tube right into the lock cylinder, and give it a good squirt. Then, put the key in, and work in back an forth a few times. See if it frees up.

If it doesn't, best way is to pull the door panel, spray the latch from the inside. Drown that feller. If it's really crusty, cleaning it with compressed air is a good idea, then spray. Try the key again, and work the mechanism. See if it frees up.

 

First off, do NOT use WD-40 on anything that has parts rub together. Lock cylinders and door hinges come to mind. WD-40 is good stuff but has limits. It will displace water great, hence the name. It's a great cutting oil too. When you're drilling a hole, it will keep the bit cool and sharp. It will also help parts grind down. 3in1 makes a great oil for lubricating lock cylinders. It will help parts slide across each other. Regular 3in1 will work, but they have some more penetrating formulas out there now.

 

For removing stuck parts liquid wrench or pb blaster is what you want. Graphite can be used after it is freed up to keep it lubricated.