Wanting to fix my non functioning door lock, I bought a Mid Fifty matching 2 door locks and ignition set.

At first the latch mechanism seemed frozen, I lubricated it a little and it got a bit better. Fitted the lock and it locked but the key barely moved and it didn't seem right, like it would only be barely doing its job. I had trouble relating what I could see through the door lock hole to what needed to happen. So I pulled the latch out of the door to see what was happening. I have taken pics to illustrate what I found in case there was any one else out there who wanted to know.

Old door lock at bottom, at center is original lock lever and at top Mid fifty replacement. New one is slightly different size but should work ok.

 

Remove these four screws to remove the door latch mechanism. It will come out ok without this next step probably. However if you reach up into the door, behind the outer door handle, is a lever from the latch. If you pull this back slightly, it will slide out easily from behind the door handle. Several photos here will illustrate how to remove the latch from the inner door handle mechanism without removing the inner door handle and mechanism.

When installing the latch back in place after removal, repair, whatever, pull the long arm on the latch that is operated by the outer door lever. slightly back, to allow it to fit behind the outer door handle button. Slide the latch fully into place and install screws. Just need to install the door lock and DONE. Mind you trying to fit the door lock has just about driven me crazy, because I did not understand what was happening and conflicting ideas about what should happen.

 

Here is the lever from the inner door handle, joined to the latch. It is sitting on a pivot point, and secured in place by a washer, with a spring underneath, which keeps pressure on it against the almost rectangular top of the post it sits on.

 

The inner door handle connecting lever can be removed by turning the latch to this position, once the latch has been unscrewed and removed from its position in the door panel. With the latch in this position, the inner door lever arm can be removed from the latch, allowing the latch to come out without removing the door handle mechanism if you wish to do so. The slot on the arm will simply pull off the pivot point on the latch in this position.

 

 

This is how the latch sits in the truck door. You may be able to tell that the sliding plate has moved up to cover and stop the movement of the long lever running up to the door handle. Notice the pivoting T piece, with the arm in between the 2 lugs the latch is LOCKED.

The plate with the two lugs will be pulled/moved to touch the left side of the T handle when the inner or outer handle is used to open the door, and moves the connected mechanism to release the latch.

 

Here you will see:-
1. The long lever from the door handle.
2. At the left top the small plate under the round hole, with the square hole in it, is the part that moves to stop the long lever working, locking the door. In this position it is unlocked, when moved (in this photo to the right, but when in the car it moves up to lock and down to unlock)

 

This is the latch side that would face the outer door panel. The left side is the bottom of the latch and right, the top. Lover side faces the front of door.
Things to see here:-
1. Long chrome lever running across the top is the lever that opens the door from the outside door handle.
2. On the left top end you will see a round hole and a square hole. Round one is the pivot point for the door lock locking lever.
3. The square hole is where the locking lever arm goes into to move the mechanism to lock and unlock the door latch.

 

n this picture you see a pivoting T piece, with 2 lugs, one at each end of the arc of travel. With the T piece in this position, against the lug on the right, the latch is UNLOCKED.

 

Here you can clearly see the round hole for the locking lever pivot, and the square hole for the locking lever arm and the plate has moved into position to lock the door by covering the end of the long lever, stopping the outer door handle from moving.

 

This is a picture through the door lock hole, showing the round pivot hole and the square hole for the locking lever arm to fit into to activate the door latch.

 

When I removed the old lock, the spring clip was inserted from the inside, and I will try it from there when I install my lock again. I think you would get a better feel for the clip going into the right position. I didn't feel confident when trying to secure the lock with the clip through this hole on the edge of the door.

 

Door slot for spring clip.

I found it awkward to get the clip properly on the lock through here, and through my own stubborness, damaged the tumblers on my lock when one ear of the spring clip did not engage properly and went across the top of the lock.

 

Lock retaining spring clip

 

My key did not turn a full 1/4 turn to lock, only to this angle, although the door is locked here, and when seen out of the car there is only a small movement between locked and unlocked.