Door lock repair

[rjd2]

So my drivers' side door lock doesn't function properly. the key can just barely shift the latching mechanism down, to lock it, but it won't unlock at the key. i've got the door disassembled, and can see it through the top of the door and the inside of the door, and have lubricated everything i can possibly see. still no luck. any lock wizards out there have any tips?

['76mintgrün'02]

You might need to remove and clean the mechanism, then add new lubrication.

The dried up old grease holds dirt and it gets gummed up.

I used a bread pan, some naphtha and a paint brush to wash these two clean.

 

EDIT:

if the lock portion of the mechanism is sliding up and down smoothly using the plunger/pin, the problem's more likely in the key portion... which I have not messed with.  Sorry.

 

Tom

 

 

Edited April 18, 2019 by '76mintgrün'02

[Harvanj]

If it end up being more then cleaning; the part of the mechanism that articulates up and down slides on fixed pins that are peened over. With age and wear the tolerances grow wider and the mechanism jams on an angle. You may be able to re peen and tighten the tolerance/gap and fix the jaming. I was initially successful with this method, over time the pins became stress fractured and jamming was worse. I had to remove the pins altogether and fab a different solution. The difficulty is when the entire mechanism is out of the door, not under load it works fine. Back in the door, with load it can jam again. Don’t put the door back together, door card and trim on until you are sure it’s functional again. 

[rjd2]

Thanks folks. I'll have a go at disassembling and cleaning, and then re-assembling. I am not going to make the mistake of installing door card/handles only to find it's still got an issue!

[tech71]

If you are going that far into your doors consider installing a keyless entry system. Not to difficult from what I gather. Search "keyless" here and lots of good info comes up.

[rjd2]

fixed it. the C shaped metal piece that throws the whole mechanism was bent inwards; after bending it towards the doorjamb, it throws up and down nicely. will lube and re-install. thanks guys!

[KFunk]

The arm that reaches from the keyed cylinder to the lock mechanism is built much sturdier on 76's (and maybe '75s), than they were on my '74.  I suspect there was a bit too much slop in that mechanism in the earlier cars and stuff got bent, so they made them better.  The updated version gives you a more confident feeling lock/unlock.  

[rjd2]

6 hours ago, KFunk said:

The arm that reaches from the keyed cylinder to the lock mechanism is built much sturdier on 76's (and maybe '75s), than they were on my '74.  I suspect there was a bit too much slop in that mechanism in the earlier cars and stuff got bent, so they made them better.  The updated version gives you a more confident feeling lock/unlock.  

I could visibly see that arm bow when the lock was thrown. My car is a '76 but I have no idea what the doors are from!

['76mintgrün'02]

If you still have the door opened up, I'd suggest making a little scraping/digging tool to clean out the seam at the bottom of the door.  I used a stiff bit of thin stainless rod with a flattened end and put a little hook in it to pull the dirt out of the corners.  That dirt holds water and leads to rust blisters.

I poured a little OSPHO in that seam after cleaning it out and will add cavity wax later on... when I get some.

[Simeon]

30 minutes ago, '76mintgrün'02 said:

poured a little OSPHO in that seam after cleaning it out and will add cavity wax later on... when I get some.

 

Does OSPHO need to be rinsed off after working? I would be concerned that I couldn’t get it all back out afterwards. 

['76mintgrün'02]

Good question Simeon.  I dunno.  I did not rinse it.

 

DISCLAIMER:  don't follow my lead on the OSPHO.  I do recommend cleaning that seam out though.  I got a lot of dusty dirt out of mine.

 

I have wondered about that in the past.  I used it on my suspension bits after sand blasting them.  It turns the steel a pretty dark grey.  I tried rinsing a few parts and they immediately flash rusted.  I recoated those before painting.  I was just reading a bit on the garage journal site, about OSPHO and they say the instructions do not say to rinse.  

 

RUSTED METALS - OSPHO is a rust-inhibiting coating - NOT A PAINT You do not have to remove tight rust. Merely remove loose paint and rust scale, dirt, oil, grease and other accumulations with a wire brush - apply a coat of OSPHO as it comes in the container - let dry overnight, then apply whatever paint system you desire. When applied to rusted surfaces, OSPHO causes iron oxide (rust) to chemically change to iron phosphate - an inert, hard substance that turns the metal black. Where rust is exceedingly heavy, two coats of OSPHO may be necessary to thoroughly penetrate and blacken the surface to be painted. A dry, powdery, grayish-white surface usually develops; this is normal - brush off any loose powder before paint application.
 

Edited April 20, 2019 by '76mintgrün'02

[Simeon]

Sounds fine, I just wasn’t sure if that was acid based and would need to be neutralised. 

['76mintgrün'02]

yes, phosphoric acid, I believe.  the instructions on the bottle say it is a primer for paint and say to paint right over it.  Nothing about neutralizing it.  Maybe not the smartest thing for me to put in the seam, but it is what I had on hand.

 

don't drip it on your concrete though.  I read that it will eat holes in the finished surface.