trunk lock

[jiho]

Here the key goes in an out OK, it just won't turn. I'm going to try ssn696's suggestion to push down on the trunk lid. Maybe jiggle it up and down. I do that with household doors and boxes with lids, why not the trunk. For some reason with the trunk I only think to jiggle the key various ways.

It helps to visualize. 😀 The difference between the trunk lock and the door locks is, the trunk lid is spring loaded trying to open against the latch, while the doors are not. This may or may not help me get it open, but I'll have to look at maybe loosening up the spring tension.

 

[ssn696]

Here the key goes in an out OK, it just won't turn. I'm going to try ssn696's suggestion to push down on the trunk lid. Maybe jiggle it up and down. I do that with doors, why not the trunk. For some reason with the trunk I only think to jiggle the key various ways.
'Overheard customer at Harbor Freight: "I figure you might as well do it right."'

Overheard on the PA System at Harbor Freight, "Harry, got another DUI." Explanation: Customer buys a $19.99 HF drill to make a couple holes, then returns it to get his money back under the 30-day return policy. Apparently, this is a 'Done Usin' It.'

 

[jiho]

(By quoting the whole thing, ssn696 preserved the original version of my post #11, which I've since edited.)

 

[jiho]

Overheard on the PA System at Harbor Freight, "Harry, got another DUI." Explanation: Customer buys a $19.99 HF drill to make a couple holes, then returns it to get his money back under the 30-day return policy. Apparently, this is a 'Done Usin' It.'

Probably fine with them. I rarely see the same people working there twice.

 

[jiho]

The difference between the trunk lock and the door locks is, the trunk lid is spring loaded trying to open against the latch, while the doors are not. This may or may not help me get it open, but I'll have to look at maybe loosening up the spring tension.

Speaking of visualizing .... The shop manual has a picture of the latch mechanism, and it doesn't look to me like spring tension on the lid could possibly account for this.

When you turn the key, the rod from the cylinder rotates a cam in the latch, which rotates a pawl, which in turn disengages the pawl from the hook -- this RELEASES the hook, rather than rotating it. So even if that hook were hung up on the striker due to excessive spring tension on the lid, the key would still turn normally, the lid just wouldn't pop open.

Anyway, that's how it looks to me now. We'll see what I visualize when I get it apart. 😀

Oh well, at least I'm learning things ....

 

[565bbchevy]

I think you would also have added tension on the trunk lid if the trunk seal was replaced which would obviously have nothing to do with spring tension but may still require pushing down on the decklid to open it.

 

[jiho]

Hmm .... I just tried pushing down on the lid, and the lid wouldn't budge at all, no matter the force. Or lift. So the results are inconclusive.

 

[jiho]

So .... I finally got around to dealing with this. Pulled out the rear seat, unbolted the latch to get the trunk open, replaced the lock cylinder.

From the factory, the latch was rotated counter-clockwise, as you can see from the various markings in this snapshot from the interior:

You can also see that I now have it bolted in roughly centered and level. The key is now notably easier to turn in the new lock.

However, the trunk lid is now slightly twisted, so that the driver-side edge doesn't quite come down to line up with the fiberglass piece on the quarter panel. Meanwhile, the passenger-side edge pushes down a bit past the fiberglass. Before, the trunk lid pretty much lined up straight at both edges (although the gaps along the sides were a bit uneven, and still are).

Driver-side on the left, passenger-side on the right:

My tentative guess is that the factory installed the latch rotated like that in order to twist the trunk lid and make it line up better, but this made the latch harder to operate, and therefore the lock cylinder, and these aftermarket cylinders aren't quite up to it.

Not sure what I'm going to do now.

 

[Texas82GP]

Could you use standard fender shims between the deck lid and the hinge at the mounting point to align the lid?

 

[565bbchevy]

Just grab the decklid and give it a good twist, that's probably how they aligned things anyways back then.