Arthritic door locks

[Kestas]

I have the usual problems with my door locks with my 91 Grand Marquis. They crap out and I replace them as needed. I started buying them two at a time now.

The problem I want to address is that even though I replace the door locks, they still require more force to open mechanically - such as with a key or the armrest button - than when the car was new. I've gone through the whole mechanism looking for binding and anyplace that excessive friction can develop, and come up with nothing. It's considerably worse in the cold winter weather. I'm afraid of breaking my key! I've even taken the latch mechanism out of the door, cleaned out any old grease, and relubed with new grease. Even this doesn't help. Has anyone been able to get back the as-new feel of the door lock mechanism? This problem only seems to plague the front doors.

[gadget73]

Does the key part work smoothly with the lock actuator motor removed? Usually whenever I have problems with one, its the lock motor crapping out. Most of the aftermarket motors are just crap. I've been buying NOS Ford motors on eBay and just changing the lock rods as needed. I actually replaced one in the Towncar this weekend. I installed it in 2005, and it was pulled from an 88. I figure I got 5 years out of a used lock motor of unknown age so I can't complain.

[Lincolnmania]

the aftermarket lock motors are no good, and it is getting harder to find nos and good used working lock motors

[1990LTD]

It sounds like I should be glad mine doesn't have P/ locks!

[GM_Guy]

Motocycle chain lube. Spray liberally in the latch mechanism. Spray some on the back of the key lock on the rotating bits.

Alex.

[Kestas]

I buy the made in china locks from eBay. Everything seems to work smoothly before I install the motor. I'll have to revisit the entire mechanism.

[jayh]

I would thorougly lube the lock cylinders and latch mechanisms with PBblaster. I would do it like once a week for about 5-6 weeks, then lube the latches with penetrating grease.

white lithium cakes up and gets thick after it attracts dust

the lock actuators to crap out alot though. iirc one of the mustang resto places has NOS actuators and I beleive they are the same or can be slightly modified to work

[Kestas]

With other cars, the door latch mechanism can be removed, cleaned, and relubed to work like new. I've done this many times. This regimen doesn't work on the panther bodies.

[85crownHPP]

I had a couple Chinese lock motors that worked great at first, then seized up, both boots had torn. Our doors get lots of rain water in them if the exterior dew wipes are old...

[Kestas]

OEM door lock motors cost $100. The chinese replacements cost $25. For that money I'll go with the chinese replacements. I don't think OEM is that much better than the chinese replacements. I find a lot of OEM parts are way overpriced for the quality put into them.

[gadget73]

Search around on ebay, you'll find NOS ones for less than China motors.

As for OEM being better, I have 3 original 1986 lock motors in my car that work fine still. The driver's side was shot when I got it, and I installed a 1988 lock motor that lasted 5 years. I just replaced it last weekend, so it was 22 years old when it was basically dead, and my others are now 24 years old. On the other hand, the Mark VII (same lock motors) has needed the driver's lock motor replaced 4 times in the last 19 years.

[sly]

I have that red axle grease for helping out my poor car's joints and used that on the latch ... well... hosed the latch with it really (used a needle fitting to inject grease in all the moving parts) and haven't had any issues since. This was about a year ago now. I had to change that lock actuator (driver door) cause the old one rusted solid or flat seized up. Thankfully I'm moving into a house and the car will be kept in the garage so that the drip water won't go directly into the lock motor (which seems to be the main issue on mine). I did fill it with that red grease as best I could (did displace some water - had issues with the front locks freezing up over the winter too) and it's seemed to help quite a bit.

[87gtVIC]

Our doors get lots of rain water in them if the exterior dew wipes are old...

We can fix that!

[BigMikeIT]

We can fix that!

Oh really. Or is more like the scene from 'Fast Times at Ridgemont High' where Jeff Spicoli wrecks Jefferson's car?:

Jefferson's Brother: My brother's gonna kill us! He's gonna kill us! He's gonna kill you and he's gonna kill me, he's gonna kill us!
Jeff Spicoli: Hey man, just be glad I had fast reflexes!
Jefferson's Brother: My brother's gonna shit!
Jeff Spicoli: Make up your mind, dude, is he gonna shit or is he gonna kill us?
Jefferson's Brother: First he's gonna shit, then he's gonna kill us!
Jeff Spicoli: Relax, all right? My old man is a television repairman, he's got this ultimate set of tools. I can fix it.