door latch adjustment problem.

[Jason]

I can't seem to get the drivers side front door latch to work reliably.

It's as if the external handle doesn't have enough travel to make the front latch work correctly.

If I adjust the links so that there is no pre-load on the front or rear latches, and adjust the external handle cable so there is no slack, then everything works fine from the internal handle, but the external handle won't reliably release the front latch.

If I shorten the front link so that the external handle releases the front latch consistently then there is enough pre-load on the front latch that it won't always unlock.

If I fiddle with it a lot I can get it so that is appears to work correctly, but sometime later, usually after a large temperature change, it will fail in one of the ways described above.

Does anyone have any suggestions?

Thanks

[DMCVegas]

Start by pushing DOWN on the interior door handle. Then unlock the door. Then pull up on that handle to open it, and then see if it latches correctly when you close it.

[Jason]

Start by pushing DOWN on the interior door handle. Then unlock the door. Then pull up on that handle to open it, and then see if it latches correctly when you close it.

It does, but I'm not sure what that means.

Pushing down on the interior handle doesn't really move other parts of the latch system, at least not as things are currently adjusted. It just makes the interior handle link move backwards in its slot in the bellcrank. There isn't any per-load between the interior handle and the bellcrank.

I should also add that I've previously done the "wedgectomy" procedure on the latches so that they'll lock when open, and that the interior of the door is currently off, so I have easy access and view of the internals.

[DMCVegas]

If the cable from the external door handle gets caught up on it's sheath, it will bind and prevent the bellcrank from resetting to its default rest position. This preloads the door latches by way of the opening rods, which causes the internal locking mechanisms to fail to slide back and forth to properly lock/unlock. That means that the latches cease to rotate and cannot let go of the striker pins, or not even rotate in order to close.

If you've pulled rods and modified the factory settings, then that may require some adjustments now.

[David T]

If the cable from the external door handle gets caught up on it's sheath, it will bind and prevent the bellcrank from resetting to its default rest position. This preloads the door latches by way of the opening rods, which causes the internal locking mechanisms to fail to slide back and forth to properly lock/unlock. That means that the latches cease to rotate and cannot let go of the striker pins, or not even rotate in order to close.

If you've pulled rods and modified the factory settings, then that may require some adjustments now.

Remove the latches from inside the doors and then clean and relubricate them. Redo all of the internal adjustments after making sure the anchor pins are properly adjusted so they slide into the latches without the head hitting. Both latches on each door must get to 2nd locking position or you should not be able to lock the door, that is normal operation. As you close the door slowly you must hear each latch click twice. You should not have to slam the door to get to 2nd locking position on both latches. Properly adjusted you should be able to close the door with 2 fingers on the rub rail pushing in the center of the door.

[Jason]

The more I watched things move, the more I was convinced the issue was the amount of travel in the external handle. So I removed the external handle and found..

IMG_20151022_160608.jpg

I don't know how it got that way, but the bend in the cable mount reduced the travel enough that it was impossible to get things adjusted properly. I bent it back straight and now it's working.

[David T]

The more I watched things move, the more I was convinced the issue was the amount of travel in the external handle. So I removed the external handle and found..

IMG_20151022_160608.jpg

I don't know how it got that way, but the bend in the cable mount reduced the travel enough that it was impossible to get things adjusted properly. I bent it back straight and now it's working.

Must have been forced at some point. At least it isn't broken.

[Delorean Industries]

Latches should not be lubricated in the context being mentioned. During my factory authorized door adjustment training Grady clearly stated that the addition of lubrication was detrimental to the proper adjustment, alignment and release tendencies of the door system. Cleaning with a premium wax and grease remover chemical or brake cleaner is crucial to move dirt and other contaminates out of sensitive parts.


While the conditions for a correct close/open latch/release event are straight forward that doesn't apply to real world door adjustments. Sync on latches etc are subjective to outside input. With both perfectly synced on release you may not even know it. A drag condition on the inner door seal, factory fiberglass thickness protrusion into the door closing zone or gravity can make this task impossible without checking all conditions first. Prior to adjusting anything always check inner gasket wear along door contact points, front to back door alignment, top to bottom fender to door gap ("gravity checks"sign of front roof box failure/glass failure/roof box sag) to get an accurate representation of what are required to be constants prior to adjustment.

[David T]

From my experience the grease that was used originally (over 30 years ago) turns into a thick gummy substance filled with dirt. It makes the moving parts of the latches more difficult to move. There is no good way to get to them and clean and lubricate them properly when they are inside the door. If you are having trouble with your doors the main causes are the sticky latches, bad door seals, out-of-adjustment anchor pins and forcing the door locked when one or both of the latches is not in 2nd locking position. Just as you cannot properly adjust the anchor pins with bad door seals you can't properly adjust the linkages inside the doors if the latches don't work easily.

[Delorean Industries]

Be it here or anywhere in the states when servicing the doors we now fully remove all four latches from the car and soak in Chem dip. Available at Walmart for 22.00 normally. NOTE: this is the consumer grade and not as lethal as the full on professional blend. Some of you may have seen or heard the carnage involved with using this chemical recently. It is so dangerous that it managed to eat through my safety gear and burn me extensively. User caution advised on both types of the dip.

If you are going the brake clean route as it is spray form you will need one can per latch. Prep work is everything and steps must be taken to protect the windscreen, interior and quarter panel glass. Door lights should be removed and all contaminates cleaned from the base of the door along with sill seals taken off. This will provide drainage for the cleaner. NOTE: you will destroy laminated glass, black abs/sem trim black surfaces and interior components with the contact of any of the above cleaners to these surfaces.