I just swapped out the lock cylinders in my truck, they worked perfect in my parts truck, but not in the new doors. neither lock cylinder floats anymore, when you unlock it and turn the key back to take it out, it locks the door again, there's no free play anymore, and also the door lock no longer has full travel anymore. but when the key is in the lock cylinder the full movement comes back. like I said, they both worked perfect in the parts truck. is there someone that's been through this? need help please, out of ideas.

 

Sounds to me like your door latches are gummed up. Try oil the latches real well (degreasing then white grease would be beat) and work it all a couple times. If the latches are gummed up the rods going to the cylinders won't be as free, which will make the locks not as free.

 

Cleaning the door latches is a good idea, but I would say you installed the door locks wrong and are now causing the rods to bind. Pull the locks back out, and check that everything works good separately. Move the rod up and down to make sure it locks and unlocks ok. If everything works well when it is apart, then something is happening when you install the cylinders. I will try to pull locks this week end and take some pics and orientations.

 

I tried cleaning one side and it seemed like it made it better, but still the same story. when I take the rod off the lock cyl. everything works the way it should. I'm not sure how I could have installed them wrong, I have another one to look at and it all matches up, I got the key slot closer to the bottom of the cyl. than the top, just like on my shop truck. I never took the rod all the way out so I don't see how I could have put it in wrong, and they're not rubbing or hitting anything. Ive been through the system a dozen times with no luck, who woulda thought lock cylinders could be so troublesome.

 

I was going to swap in different cylinders but noticed the little lever arm on the back of the cylinder was different between the old and new. Instead of swapping the whole cylinder, I opened them up and swapped out pins to fit the keys. Had to file some. Took about an hour but they all work fine.
Just to highlight that not all lock cylinders are the same.

 

yeah I've done them before and had to swap out the levers on the back, but before I pulled these out of the parts cab I checked them and they worked perfect

 

the lever arm on the back CAN be different, I had the same thing on a truck I was fixing for the boss. Had another pair of door locks with key, put them in, only locks with key and unlocks when you pull the key out. Look at the lever arm on your old locks and on your "new" locks, you will see a difference in the arms, your original ones will have space for the innards of the cylinder to turn, I would bet that on your new ones that the arm is in a fixed state, and that is why they only lock and unlock with the key in the cylinder. I switched the arms on the ones I was working with and function returned to normal. It took me a while to see it but when I saw it I felt pretty dumb, I think the locks I used were out of a crewcab or some other ford application, but they looked identical to the truck door lock cylinders

 

2x on the lever arms being different.

Outside profile is same, but there is a half moon cutout were lever attaches to lock,

Pull the Clovis and swap out the levers

 

 

D2AZ-6521970-A .. Lever-Door Lock Cylinder-Includes retaining ring / Obsolete

1973/79 F100/350 & Bronco // 1972/79 FoMoCo Passenger Cars except 1978/79 Fairmont/Zephyr & 1979 Mustang/Capri.

PARTS INTERNATIONAL in Farmers Branch TX has 50 = 888-727-0418.

GREEN SALES CO. in Cincinnati OH has 70 = 800-543-4959.