Door locks - cannot adjust them to work - worn parts diagnosis

[TTait]

Drivers door lock, in the front, on one of our cars is just about shot I think.

I removed all 4 latch/locks, cleaned and lubed them and carefully followed first the manual, and then Martin's video to adjust them. The passenger door was perfect - the drivers door front latch continues to be a problem. I readjusted the whole door again - no better. Once I lock and unlock the door the front latch is reluctant to unlock again. Striker pin alignment is good.

I took the car to DMC-CA and they again adjusted the drivers door. They thought they had it, but its still jamming as it turns out just a day later. Its got to be worn hardware a this point...

So... Sage advice here please. Is there a particular component that is most likely to be worn? The latch itself I assume? Do I also need to replace the link rods, bell crank? I want to get it right but prefer to not just throw parts at it - what is the best method for advanced diagnosis? What is most likely to have failed? Are the latches like headlights - always replace them in pairs or quartets?

I'd like to take the door apart again one more time and know its fixed when I'm done. I'd prefer to not just throw $300 at it, but if I have to...

WWMD? (What would Martin do?)

Advice appreciated.

Tom

[kings1527]

Tom,

I'm still a little bit fuzzy on exactly what's going on but I had what I think is a similar situation not long ago. My situation was this: I would unlock the door and then open the door on the passenger's side. As I would go to close it again, it wouldn't latch. Eventually through some finagling, I was able to get it to lock shut for the drive home. But once that happened, if I tried opening the door from the outside, it was jammed closed (primarily the front lock wouldn't disengage).

As I get home and try to open the door, it wouldn't open still. I took the top door panel off and eventually get the door to open up. After some investigation, I found out that the bell crank wasn't moving far enough to actually activate the locks to keep the door shut. That's why I'd close the door but it wouldn't click shut; the locks constantly stayed open. I had to move the bell crank about 1/8" to get it to move into position. After that, the door would lock shut fine and open from the outside or inside fine.

It turns out that the bicycle-brake cable looking thing attached to the bell crank was binding up internally, not letting the bell crank slide all the way forward. I squirted some white lithium grease in there and it's been fine since. I attached a pic showing the cable.

Maybe that'll help you. Not so much an alignment issue but strictly mechanical.

21629

[dmc6960]

Try cycling everything manually. Close the latches without shutting the door. Then lock, unlock, and test to see if the latches open. Repeat test many times (since you said it took a few cycles to go bad again). A helper would be useful. This would identify the issue (or possibly eliminate) in the door, and not the striker alignment. Perhaps its not an alignment issue of the door but the impact of the door shutting is still throwing something off internally.

Also check to make sure your latches are screwed in tight. I had an issue a while back where after I did major service in my doors, one of them (drivers) started making rattling noises and not closing well. Turns out the latch was coming unscrewed. One screw fell out completely and the other two were really loose. The split-lock washers had collapsed and were no longer providing tension to keep the screws tight.

[WelmoedJ]

The long non-adjustable rod is held in place halfway (approx below the door handle) by a plastic clip with lock.
The long rod in my car came free from that clip each time the locking mechanism was used.
This caused the front locking mechanism not to unlock fully.
This was due to bending of the rod when force was applied to unlock and so the latch didn't work.

I replaced the clip by a (insulated against rattling) clip and the problems were over.
Check that plastic clip and replace if it fails to hold the long rod in the correct position.

[Josh]

I have this EXACT same problem. Thanks for making this thread.

[Patrick C]

A trick that I was taught, and have used for 10 years, is that the front locking rod is NOT needed and only complicates things. The door will stay securely locked with only the back lock engaged. Obviously both the front and rear door latches will still operate, however only the rear latch will "lock" when the button is pushed with this modification. Simple is better!

When I had the front "Z shaped" lock rod, it would tend to bend and spring back, preventing the doors from locking. Removing it made them work flawlessly.

And for those with the door lock actuators, they can still be used by cutting the rod like so (photo courtesy of Matt Spittle many years ago):

[Josh]

A trick that I was taught, and have used for 10 years, is that the front locking rod is NOT needed and only complicates things. The door will stay securely locked with only the back lock engaged. Obviously both the front and rear door latches will still operate, however only the rear latch will "lock" when the button is pushed with this modification. Simple is better!

When I had the front "Z shaped" lock rod, it would tend to bend and spring back, preventing the doors from locking. Removing it made them work flawlessly.

And for those with the door lock actuators, they can still be used by cutting the rod like so (photo courtesy of Matt Spittle many years ago):

So simple, but it makes a world of sense. Obviously not everyone will like this fix but for me, out comes that rod! I did notice it had a significant amount of flex in it.

However, what if the latch bounces to the locked position? That would cause some issues. However, it would be highly unlikely for this to happen with both doors at once.
But for now I will just remove the rod, thanks for the idea patrick. I have some spare latches that I will experiment with when there are not bigger issues to deal with on my car (it is currently in two pieces and lacking any spark/fuel management haha)

[DMCMW Dave]

However, what if the latch bounces to the locked position? That would cause some issues. )

You'd be locked in/out and you would have to take the door panel off with the door closed.

[Josh]

You'd be locked in/out and you would have to take the door panel off with the door closed.

I have already been there with installing my doors. I have the drop glass rolled all the way down so I can pop the door without looking. Just need to sort these door gremlens out so I can be confident locking the door.

[Patrick C]

So simple, but it makes a world of sense. Obviously not everyone will like this fix but for me, out comes that rod! I did notice it had a significant amount of flex in it.

However, what if the latch bounces to the locked position? That would cause some issues. However, it would be highly unlikely for this to happen with both doors at once.

Glad to help! The latch bouncing to the locked position would be extremely difficult. In probably 10 years and nearly 45,000 miles of driving on the bumpiest back roads in Northern Michigan, I have never had the front latch bounce locked.

[Josh]

Glad to help! The latch bouncing to the locked position would be extremely difficult. In probably 10 years and nearly 45,000 miles of driving on the bumpiest back roads in Northern Michigan, I have never had the front latch bounce locked.

That is good enough for me :D

[SS Spoiler]

I also removed the front locking rod and have no problems.

[David T]

I also removed the front locking rod and have no problems.

It is very possible the front latch is worn. After years of forcing a door that is out of adjustment parts inside the latch can wear. If you are satisfied you cleaned and lubed it and adjusted it properly you probably need a latch. Since you successfully adjusted the other door I can assume you know what you are doing. Make sure both latches on each door achieve second locking position. I don't recommend removing the locking link for the front latch but many have done it. IMHO you should make it work correctly. It can be done, removing the link is a short-cut.
David Teitelbaum

[Josh]

It is very possible the front latch is worn. After years of forcing a door that is out of adjustment parts inside the latch can wear. If you are satisfied you cleaned and lubed it and adjusted it properly you probably need a latch. Since you successfully adjusted the other door I can assume you know what you are doing. Make sure both latches on each door achieve second locking position. I don't recommend removing the locking link for the front latch but many have done it. IMHO you should make it work correctly. It can be done, removing the link is a short-cut.
David Teitelbaum

That is a good point David. I am not one to cut corners. However in my current situation with the car, I would rather pull the rod so I have functioning doors and spend my hours getting the engine running. When I have a decent driving car I can revisit the doors and perhaps replace the latches.

[TTait]

It is very possible the front latch is worn. After years of forcing a door that is out of adjustment parts inside the latch can wear. If you are satisfied you cleaned and lubed it and adjusted it properly you probably need a latch. Since you successfully adjusted the other door I can assume you know what you are doing. Make sure both latches on each door achieve second locking position. I don't recommend removing the locking link for the front latch but many have done it. IMHO you should make it work correctly. It can be done, removing the link is a short-cut.
David Teitelbaum

I still will do some diagnostics as suggested here - but is is kosher to just replace 1? $40 each isn't a deal killer - anything else I should replace at the same time if I do the locks?

[DSNW Toby]

I still will do some diagnostics as suggested here - but is is kosher to just replace 1? $40 each isn't a deal killer - anything else I should replace at the same time if I do the locks?

Tom - Have a look at this. With the window down and door closed, reach in from the outside and slowly lift the latch handle. Watch very closely for any slight movement of the lock toggle while lifting the latch handle. We have found that several cars had these annoying intermittent door jamming issues, and it turned out to be a very slight riding condition between the latch linkage and the end of the forward lock linkage rod. When the latch handle is lifted, it causes the lock rod to pull the forward lock into a slightly locked position (not quite locked, but somewhere in between). The solution is to grind a small amount off the end of the lock linkage rod to eliminate any touching between moving parts.

This is a very subtle issue, but we have had great success with "problem doors" when performing this analysis and modification. Note: it is fine to replace single latch assemblies without changing all of them. A careful lock/latch adjustment needs to be done anytime hardware is changed. I prefer using the service bulletin over the shop manual.

[mluder]

Just to make sure I'm clear what the original poster's issue is as I THINK it's the same problem I'm having.

I have disconnected my door lock modules so I'm all manual locking and unlocking.
I can lock and unlock either door all day long from the outside with a key and there are no issues.
If I lock the driver's door from the inside "lever" when it's closed it will not unlock from the same lever. It takes repeated lock and unlock motions on the lever to get it to finally release. My fear is one day I may get locked inside. It's happened before - hence the disconnected door lock module.

Any way - is this the same issue that may be a bending or disconnecting of the front lock bar or a different issue all together.

Input would be great.

Cheers
Steven

[WelmoedJ]

Just to make sure I'm clear what the original poster's issue is as I THINK it's the same problem I'm having.

I have disconnected my door lock modules so I'm all manual locking and unlocking.
I can lock and unlock either door all day long from the outside with a key and there are no issues.
If I lock the driver's door from the inside "lever" when it's closed it will not unlock from the same lever. It takes repeated lock and unlock motions on the lever to get it to finally release. My fear is one day I may get locked inside. It's happened before - hence the disconnected door lock module.

Any way - is this the same issue that may be a bending or disconnecting of the front lock bar or a different issue all together.

Input would be great.

Cheers
Steven

The inside lock rocker can be a bit misplaced, causing the behavior you mentioned.
The rocker position is adjustable by the two screws on the mount.
Once inside the door take a good look at the rocker's rod while moving the rocker.
It may well be that it's a bit out of the corrent position causing the trouble you notice.

It also can be that the connections of the rocker rod are worn.
But first check the position, if necesseary "play" with the adjustment screws.

[David T]

The inside lock rocker can be a bit misplaced, causing the behavior you mentioned.
The rocker position is adjustable by the two screws on the mount.
Once inside the door take a good look at the rocker's rod while moving the rocker.
It may well be that it's a bit out of the corrent position causing the trouble you notice.

It also can be that the connections of the rocker rod are worn.
But first check the position, if necesseary "play" with the adjustment screws.

IMHO the majority of door problems occur when the door is not properly closed and/or the locking pins are not properly adjusted so the door is closed but both latches are NOT in second locking position. If you try to lock the door that way it won't lock but if you keep forcing the mechanism eventually you can get it to stay locked. In the process you bend the linkage and mess up all of the internal adjustments. The other problem is after all of this time the lube used in the latches is very gummy and the latch mechanisms do not move freely like they are supposed to. Lastly, all too often the doors rattle because the seals are shot. Instead of replacing the seals someone gets the bright idea to adjust the locking pins to pull the door in tighter but they don't get it right and both latches are not in second locking position (again). By removing the locking rod to one of the latches you get around the synchronization problem of having both latches in second locking position when closed. Not the "fix" I recommend.
David Teitelbaum