Door Lock Issue

Paint, body preparation and modification, interior work and electrical
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jeffball610
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Location: Las Vegas, NV

Door Lock Issue

Post by jeffball610 »

Recently my driver's door has failed to unlock from the key. It locks just fine, but won't fully unlock with the key. Thankfully, my trunk works fine and the stock jack "wrench" can reach inside the lowered window to pull up on the lock plunger ;-)

I went through the door linkage about a month ago to clean and inspect things and everything seemed fine and has worked until recently. Is there a common issue that fails that I should be looking for? It seems "spongy" when trying to unlock. Perhaps a failed plastic clip binding?
1972 Datsun 510
7-bolt 4G63T, EVO 9 pistons & rods, Garrett GT2971R, "Flipped" Stock Intake Manifold, Toyota R154, Z31 R200 w/ CVs
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Byron510
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Re: Door Lock Issue

Post by Byron510 »

The most common issue... the linkage literally bends over time, which changes the range the lock tumbler and leaver can move the mechanism....

Just a place to start, anyways.

Byron
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because the opposite never works.
Three B's Racing
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Re: Door Lock Issue

Post by Three B's Racing »

What Byron said and is why it's important to use good lube on all those moving parts. I'd have a look and make sure nothing got bent but first I'd spray some graphite in the lock itself as it can simply be jammed up some due to moisture.
"Lastnight the wife said oh boy when your dead you can't take nothing with you but your soul oh "Think"
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jeffball610
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Re: Door Lock Issue

Post by jeffball610 »

I took things apart today to get a better look at what was going on. It seems the lock or the "bracket" aren't working correctly. I got some video of it. What do you guys think?

https://www.youtube.com/watch?v=Ao6SBPNyjbE
1972 Datsun 510
7-bolt 4G63T, EVO 9 pistons & rods, Garrett GT2971R, "Flipped" Stock Intake Manifold, Toyota R154, Z31 R200 w/ CVs
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jeffball610
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Joined: 15 Sep 2006 14:12
Location: Las Vegas, NV

Re: Door Lock Issue

Post by jeffball610 »

At this point I'm looking to replace my locks and just key them to my current keys. However, new 510 locks don't seem to be common or reasonably priced. The 240Z stuff seems more common and better priced. This ebay listing says it fits 240Z etc. and 510. Are the locks similar enough that this will work?

http://www.ebay.com/itm/DOOR-LOCK-KEYS- ... BD&vxp=mtr

Edit: Actually, a bunch more listings just showed up today that look promising and reasonably priced. I'd still like to know if they swap over though.
1972 Datsun 510
7-bolt 4G63T, EVO 9 pistons & rods, Garrett GT2971R, "Flipped" Stock Intake Manifold, Toyota R154, Z31 R200 w/ CVs
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D52E
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Re: Door Lock Issue

Post by D52E »

I believe the 240z locks had an additional indexing rib cast on the outside of the lock cylinder. I re keyed a 240z set a while ago for my 510 (used Nissan parts, not aftermarket). I believe I just ground down the extra rib and swapped the 510 arms on the backside.

I would also suggest to check the linkage rods for bending. I had a 510 once that would not unlock but it would lock. It was as if the stroke on the lock cylinder was insufficient in one direction. I bent the linkage rod slightly to tune the lock/unlock stroke a bit. It's still not perfect but it's much better.
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D52E
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Re: Door Lock Issue

Post by D52E »

1969 510 lock on left side with S30 linkage arm. S30 lock on right side with S30 linkage arm.
Image

Notice the indexing rib not present on the 510 lock (left side)
Image
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jeffball610
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Re: Door Lock Issue

Post by jeffball610 »

I bought a set of locks from Z Car Depot for a 240Z, and they work :) You might need to turn the tab 180 degrees for one side of the car, but they seem to work just fine.
Image

My issue seems to have stemmed from a spacer/cushion-thing on the arm that actuates the lock from the tumbler. Mine was still soft, but very loose in the mechanism. My passenger side didn't have it at all. Without this part, the key will not be able to turn enough to lock or unlock a door. I'm not sure why they went with this design over a more direct actuation, but it seems to be the root of my issue.
Image
Image

Since I was missing the passenger side and the driver side wasn't working right, I came up with a solution. It is probably only temporary since it's soft rubber, but I took a small vacuum nipple and cut the end off and cut it in half. I slid it over the actuation arm, and it works great. Very direct action on the locks with the keys.
Image
Image
Hopefully this will help someone else who might be having issues with their door locks from the key and by using a more available tumbler from a 240Z, maybe we can keep a few more cars on the road.
1972 Datsun 510
7-bolt 4G63T, EVO 9 pistons & rods, Garrett GT2971R, "Flipped" Stock Intake Manifold, Toyota R154, Z31 R200 w/ CVs
Three B's Racing
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Re: Door Lock Issue

Post by Three B's Racing »

That is an awesome fix. Some delrin tubing will be the best fix option.

Thanks
"Lastnight the wife said oh boy when your dead you can't take nothing with you but your soul oh "Think"
- John Lennon
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jeffball610
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Re: Door Lock Issue

Post by jeffball610 »

Three B's Racing wrote:That is an awesome fix. Some delrin tubing will be the best fix option.
Agreed. I'm sure others will begin to have issues (if they haven't already) with their locks. The stock piece is just plastic and will wear our or break over time and use. I know my rubber tubing fix won't last forever, but it works right now and will be easy enough to replace.
1972 Datsun 510
7-bolt 4G63T, EVO 9 pistons & rods, Garrett GT2971R, "Flipped" Stock Intake Manifold, Toyota R154, Z31 R200 w/ CVs
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