How Stiff is Your Thing? Options

[bkrantz]

Mine is too stiff, I think. Oh, the thing I mean is the internal door latch mechanism. And the part that seems stiff is the locking function.

In case your never spent any intimate time with the mechanism, the locking function is done by a stamped plate that shifts up (to lock) and down (to unlock). I continue to have problems unlocking the doors with keys, even after Curt did his magic on the cylinders.

Since the up-down shift of the locking plate is accomplished by the little lever on the internal end of the cylinder, as twisted by the key, so it would seem to be better if the plate shifted without much resistance.

Oh, and I have tried some different lubes.

[bkrantz]

Thanks, guys. Here is an annotated version of the photo that shows what I think is going on.

The dashed red outline is the locking plate. This is attached to the main latch base only at the bottom (right side) by a permanent rivet, with the large circular washer. The locking plate shifts up and down (left and right--red arrows). The locking plate also rotates around the rivet, which is how lifting the outer door handle unlatches the closed door.

As it does so, it also rotates the lever (dashed blue outline) which then moves the long rod on the door forward or back (blue arrow). The rod connects to the inside door lock button that either sits flush with the inside handle or pokes out. Of course this linkage also works in reverse, and moving the inside lock button moves the rod which moves the lever (blue outline) which shifts the locking plate (red outline) up or down.

The green arrow shows where the locking plate and door bar level meet.

First of all, what mad scientist came up with this design? Did the Porsche/Karmann families have some clever but insane cousin they kept locked in the basement?

Second, the resistance to shifting the locking plate seems to be (1) the lower pivot (rivet), (2) the pivot for the locking bar rod lever, and (3) the drag along the long rod and and internal door lock button plus the miscellaneous contacts of all the parts. On this latch I am pretty sure the lower pivot is pretty loose. I am not sure about the rod lever pivot. I will check that out. My concern is that twisting the key, which rotates the little arm on the inside of the cylinder, has to do LOTS of work, and can bind.

Third, do I really need the internal door lock button to function? If not, at least I can at least disconnect the rod, and the drag of all the stuff "downstream". I could even disconnect the rod lever (as mlinder suggested)--just by removing the spring?