How it works
XJ6 door latching and locking employs a rectangular block mounted on the outside of the door edge that latches onto a U-shaped striker bar screwed into to the opposing door frame.
Striker bar hold
As the door is closed, the striker moves toward the latch inside the rectangular outside block. Impact against the latch causes it to rotate counter-clockwise, capturing the striker bar.
When activated, a second lever moves up and forces the latch back into its original position, freeing the striker bar.
The outside latch is controlled by a complex four-lever mechanism bolted inside the door shell; linkage rods connect the a) interior open lever, b) interior lock lever, c) exterior handle button, and d) exterior key lock cylinder.
The mechanism levers are identified by their pivot points in the illustration above.
- 1 when the inside door lever is pulled, the arm moves down, allowing the pin to move up and release the door
- 2 when the inside lock is set, the arm moves up, shifting the lift tab away from the pin thus locking the door
- 3A/3B similar to (1), when the outside handle button is pressed, the arm moves down, and the door is released
- 4 similar to (2), when the outside cylinder lock is turned, the arm moves up, shifting the lift tab to lock the door
All the action centers around the pin in the outside rectangular block (see orange circle with crosshair above) that manipulates a rotating catch.
The following drawings (not to scale) illustrate how the lever mechanism works … really quite ingenious.
When the door is opened and the outside handle button released or the inside control lever relaxed, a spring moves the pin up and that releases the rotating catch.
A safety feature blocks locking unless the door is already latched (closed) or the outside handle button is first pressed before flipping the inside locking lever (a rather awkward movement, but a “feature” nevertheless). The primary logic of this safety blocking is to prevent the accidental locking of the front driver door (by inadvertently flipping the interior lock lever while exiting the car, for example, or by simply forgetting that keys were left in the car and not in a pocket or purse).
When the door is closed (and it is therefore latched by the bar striker in the door frame), the pin is released and drops down via spring action. Pressing the outside handle button or moving the inside control lever will push the pin up and unlatch the door which can then be opened with a gentle push or pull.
Turning the key (clockwise on the left and counter-clockwise on the right … well, it’s a Jaguar) or flipping the interior lock tilts the mechanism lever (3A/3B) so that the tab can no longer push the pin up.
When the door is locked, pressing the exterior door handle button has no effect.
Common part failure
A common part failure involves the linkage rods and the little clip (BD44650) that holds rods to various levers.
The BD44650 clip was discontinued a few years ago, but an aftermarket alternative, Dorman 75455, works just as well.
Frequently used doors and levers tend to have linkage clips wear out, especially since the gripping part is made of plastic. When the clip fails, the linkage rod will slip out of its position, causing locking and latching functions to fail.