Sticky doors

[notny41]

Is there a good way to remedy a sticky door? It opens fine but when I go to close it, I have to give it much more effort than I do on the other side of the car. Is it just a matter of cleaning off all the old grease and grime from that little arm?

door arm.jpg (869.81 KiB) Viewed 388 times

I know...gross, right?

[Tom]

White lithium grease usually helps, but if the problem keeps coming back, your hinge may be loose or wearing out, or the door may be out of alignment, or the door check inside might be failing. Door checks tend to clunk and make noise when they are bad. I did one on my 450SL a few years ago, and it was a total pain. The 944 doesn't look as bad, but I've never changed one....

[notny41]

Tom, that definitely helped to spray with White Lithium grease. Thanks!

The curious part of me would like to know how it could have binded so badly though... It took serious force to close the door.

[Tom]

Check to be sure the hinge is tight and the door is aligned well. If the lithium 'wears off' in a few months, that's usually a sign of alignment/hinge/check issues.

[dr bob]

As hinges wear over time, the alignment between the latch and the striker loop or pin is slowly lost. The position of the striker is adjustable, as the screws holding it pass through slightly larger body holes, and actually engage a plate with the threaded holes that sandwich the door jam metal when tightened. I use layout die on the striker to see where the latch is actually hitting it first. I've used masking tope there too, and gently push the door onto the striker until contact then inspect for marks that indicate that first contact. Adjust the striker location slightly and test again until the striker no longer needs to lift the back of the door. If that needed 'lift' is serious, adjust the hinges, then the striker position.

If that striker has been adjusted in the past, there's a chance that it's moved in some, demanding that the door needs to close further than normal before the latch will engage. That can also happen if the latch has been pushed by the misaligned door over time. Adjust the striker horizontally to the point where the door is not quite closed when latched. Gradually adjust the striker so the door is barely to the point where the reflection at the rear edge gap is perfect.

Aligning the door is a bit of an art, where you need to support the rear of the door well to get hinges set up perfectly to support the perfectly door in the opening. I usually just remove the striker when testing or adjusting hinges. Use masking tape to help remember where the striker was previously positioned. Once the hinges are perfect, only then go after the adjustment of the striker. Adjust for perfect gaps and reflections between panels before adjusting the striker.

Housekeeping: Cleanliness is essential at hinges and latches, as dirt/crud/etc. can increase wear in the hinges. The pins must be properly lubricated. I make cardboard 'shields' to slide into the jams so I can lubricate hinge pins without leaving a mess, and also not gather more crud.

The door stay in your picture needs to stay clean. The rollers inside the door get lubricated but the bar stays clean/dry.

The door latch mechanism deserves regular cleaning and attention too. The sliding pieces get lubricated, as do the lock and the actuator linkage from both inside and outside handles. For the exposed part of the latch where it hits the striker, use something light that won't stain clothing on accidental contact. A thin film of silicone grease or maybe even Vaseline in the V that latches over the striker is good. Clean first, then lubricate.