Ok, how do I remove it? I've been able to tear down everything else, but I can't figure out how to get the lock cylinder out. Is there a special tool? I'm used to cylinders that have a backing spring clip.

Thanks!

I'm not positive on a '77, but on my earlier spiders, the trunk lock cylinder is secured by a large nut in the space between the outer body panel and the inner trunk panel. Remove the trunk latch mechanism first. You then can remove one of the 3" dia. or so panel plugs in the rear of the trunk, the one right above the lock. The nut can then be spun off with a combination of flat-bladed screwdrivers, needle-nose pliers, and swearing. Be careful not to drop the nut into this recess when it spins off, as they're hard to retrieve.

-Bryan

Subsequent thought: Or were you asking about removing the lock cylinder with the 5 "tumblers" once you have removed the lock assembly from the car? If so, my recollection is that there is a circlip at the end, and once that is removed and you insert the key, you should be able to turn the inner mechanism to line things up so that you can pull out the cylinder. Careful: Lots of small tiny parts here that can go flying off into deep corners of your work area....

-Bryan

Thanks for the reply! You're first assumption was correct - I'm trying to get the nut off the cylinder so I can remove it. I was trying with screwdrivers and pliers, but can't seem to get it. If anybody knows of a tool made for these, I'd love to find one.

Thanks!

It is rather tricky, and I'm sure there is a Fiat tool for it although I don't know what it looks like or how to get one.

There should be three "cutouts" in the outer circumference of the nut. I've always just inserted a screwdriver into one of those cutouts and gently tapped on the screwdriver with a hammer. The nut slowly starts moving, and you just have to keep moving the screwdriver around and tapping on different cutouts until it is loose enough to remove by hand. Some penetrating oil might help, letting it soak for a few hours.

At some point the nut will be backed off enough so that the lock cylinder itself can rotate, so you can hold the nut and continue unscrewing the lock cylinder.

-Bryan

PS: This is what that trunk lock cylinder nut should look like:
https://www.midwest-bayless.com/p-17270 ... e-nos.aspx

If you have something different, someone's been in there before you...

-Bryan

Yup, that's the one. I'll get back there and try messing with it once I'm done pulling the interior. I have it soaking with everybody's good friend PB Blaster now.

Thanks!