Re: 1948 door latch
Posted by DavidPackard On 2017/4/22 11:43:41
I've got a short up-date on the difficulty I'm having with locking the driver's side door on my '48.
Just to review, the latch works fine, the outer handle opens the door, the inner handle opens the door, but neither the key nor the button will lock the door. The button will not 'stay down' and will just pop-up every time it is pushed down.
Yesterday I removed the key cylinder and connecting shaft . . . that did not change any of the symptoms. The only good news is that I have successfully reinstalled the cylinder lock without removing the door panel, or resorting to the long needle method (aka stabbing the door panel).
Before you throw out that old set of windshield blades take a look at them and if they have two pieces of metal (stainless steel) on either side of the rubber wiper element, then rip the mess apart and harvest the pieces of stainless. I used a small 'tie-wrap' to strap this wiper stiffener to the Packard lock shaft and used it to support and guide the shaft into the latch assembly. Once you think the shaft is engaged slowly remove the stiffener . . . there is just enough room . . . the cylinder needs to be slightly pointed upward to remove the stiffener. The 'tie-wrap' is now captured between the latch and cylinder. I must admit it took more than one try and in each case the 'tie-wrap' was still just where it was before I removed the stiffener. If the 'tie-wrap' is tight enough it does not seem to move when the stiffener is removed.
Now that I know it is not the cylinder lock my best guess is that the small leaf spring that holds the button in either the full-up or full-down position has lost some integrity. Without that holding feature the torsion spring on the button lever is winning the contest (see photo). It's just a guess at this point, but after seeing the wear the three pawls have caused on the ratchet side of the 'star' I think I should be looking for a serviceable replacement latch.
Given the photos that BDeB posted I would say the failure of that one feature of the 'master pawl' would render the latch inoperable (no way to move the other two). The problem I'm having is the broken part appears that it might have a tear in the metal that occurred during manufacture, and thus the failure mode with initiated by fatigue. Gross overload may not be necessary, only a whole bunch of cycles (door openings) and less that optimal lubrication. BDeB's photos also illustrate that the door latch was not considered a serviceable component, in that the tool of choice to disassemble would be a drill. My experience with latches leads me to believe the rivets were used simultaneously as fasteners, pivot points, and spacers.
I would like the opinion of this forum on the possibility of modifying the 'B' pillar before this type of failure occurs. I was thinking on what would be the necessary steps to unfasten the lock striker (with the door closed) and thus defeat the entire lock. I'm not entirely sure this would work on 8deluxe's club sedan but might help on a four door design. I was thinking of transferring the location of the four striker screw locations such that their location would be obvious then the rear door was open. Also I would modify each screw such that there was a lathe center located in the end of the screw. Then, if in the future, a failure was to happen the 'back side' of the screws could be drilled enough to compromise there shear area. I believe a 'left-handed' drill would be required because a 'right-handed' drill could 'un-screw' the fastener before the drill removed material.
I guess the question for 8deluxe is (assuming the door is still un-opened), whether the rear seat side trim panels could be removed for an inspection on the feasibility of drilling the striker screws?
dp
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Just to review, the latch works fine, the outer handle opens the door, the inner handle opens the door, but neither the key nor the button will lock the door. The button will not 'stay down' and will just pop-up every time it is pushed down.
Yesterday I removed the key cylinder and connecting shaft . . . that did not change any of the symptoms. The only good news is that I have successfully reinstalled the cylinder lock without removing the door panel, or resorting to the long needle method (aka stabbing the door panel).
Before you throw out that old set of windshield blades take a look at them and if they have two pieces of metal (stainless steel) on either side of the rubber wiper element, then rip the mess apart and harvest the pieces of stainless. I used a small 'tie-wrap' to strap this wiper stiffener to the Packard lock shaft and used it to support and guide the shaft into the latch assembly. Once you think the shaft is engaged slowly remove the stiffener . . . there is just enough room . . . the cylinder needs to be slightly pointed upward to remove the stiffener. The 'tie-wrap' is now captured between the latch and cylinder. I must admit it took more than one try and in each case the 'tie-wrap' was still just where it was before I removed the stiffener. If the 'tie-wrap' is tight enough it does not seem to move when the stiffener is removed.
Now that I know it is not the cylinder lock my best guess is that the small leaf spring that holds the button in either the full-up or full-down position has lost some integrity. Without that holding feature the torsion spring on the button lever is winning the contest (see photo). It's just a guess at this point, but after seeing the wear the three pawls have caused on the ratchet side of the 'star' I think I should be looking for a serviceable replacement latch.
Given the photos that BDeB posted I would say the failure of that one feature of the 'master pawl' would render the latch inoperable (no way to move the other two). The problem I'm having is the broken part appears that it might have a tear in the metal that occurred during manufacture, and thus the failure mode with initiated by fatigue. Gross overload may not be necessary, only a whole bunch of cycles (door openings) and less that optimal lubrication. BDeB's photos also illustrate that the door latch was not considered a serviceable component, in that the tool of choice to disassemble would be a drill. My experience with latches leads me to believe the rivets were used simultaneously as fasteners, pivot points, and spacers.
I would like the opinion of this forum on the possibility of modifying the 'B' pillar before this type of failure occurs. I was thinking on what would be the necessary steps to unfasten the lock striker (with the door closed) and thus defeat the entire lock. I'm not entirely sure this would work on 8deluxe's club sedan but might help on a four door design. I was thinking of transferring the location of the four striker screw locations such that their location would be obvious then the rear door was open. Also I would modify each screw such that there was a lathe center located in the end of the screw. Then, if in the future, a failure was to happen the 'back side' of the screws could be drilled enough to compromise there shear area. I believe a 'left-handed' drill would be required because a 'right-handed' drill could 'un-screw' the fastener before the drill removed material.
I guess the question for 8deluxe is (assuming the door is still un-opened), whether the rear seat side trim panels could be removed for an inspection on the feasibility of drilling the striker screws?
dp
Attach file:
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