- Thread starter
- #26
Dihtung Glava
Proven Member
- 138
- 136
- May 16, 2022
-
Kranj,
Europe
Tiny fix, but it put a big smile on my face so I'm just gonna write it up while I'm waiting for my "go fast" parts to arrive
For as long as I've had this car, I've been opening the trunk via the lever in the cabin. At first even that wasn't working, but I fixed it with new hatch struts. The lock in the back of the car never worked. After changing out the struts in 2022, I sprayed it full of WD-40 but it didn't help. For some reason I just left it like that. Until now - I have decided to fix the damn trunk lock. (I'm gonna write this up tutorial-style like I did for fender rolling, in case anyone else is experiencing the same issue)
Start inside of the car by removing the central part of the plastic trunk trim. This will give you access to the latch:
Undo the two 12mm bolts and take it off to reach the lock. I don't have a picture of it, but it will be held in place with a single spring clip, you'll figure it out. Once you have it off, you're done on the inside of the trunk. Remove the center tail light piece and you'll be able to pull the lock out.
On the back, it's gonna have a small e-clip holding the lever in place. Be careful when you're taking it off, the top piece on mine broke very easily:
(this is still functional, but it was an unnecessary mistake)
After that, you can very easily wiggle the spring off of the rotor and cylinder. I simply spun it one direction until it was loose enough to be pulled off. Next, you will need to remove the cover off of the front. I did this by hammering a small screwdriver under the folds, where the cover is pressed onto the cylinder:
(there is one of these folds on each side of the cover, be gentle with them - you will need to fold them back down when you are done)
Depending on how messed up your lock is, after you have the cover off you might be able to simply pull the rotor out of the cylinder, but in most cases you will have to insert the key to get the pins aligned and pull the rotor out with the key in it.
This is where I found what was wrong with mine:
Even with the key inserted, the last pin doesn't come down far enough to allow for the rotor to be spun inside the cylinder. It was even more apparent when I got the rotor out:
This is the result of a worn key. The last tooth on the key is not long enough to push its pin all the way down, as it is worn-down and rounded off from its many years of service.
And since no one wants to get a new key just for the trunk, we have to fix this by either replacing that pin with a different one or taking it out of the equation completely. Be very careful when taking the pins out, they are spring-loaded and if they are mixed up, the lock will not function.
This is what each of the pins look like out of the rotor, they are more "gates" than actual pins:
The rectangle in the middle will be positioned differently from pin to pin, so that they match the peaks and valleys in the profile of the key. You can disassemble several locks (from parts cars and such) and collect many of these pins to have an inventory on-hand. If you can find a pin with a tight enough rectangle for your worn key to displace, simply put it in its place and reassemble the lock. There are not many variations of these pins, so this is a viable solution.
Another solution is to file the pin down until it no longer catches in the cylinder. As they are very soft, this takes about 10 seconds:
If your pin only has to be altered by a fraction of a millimeter, the lock might remain functionaly the same. In my case I had to shave off quite a bit of material, so the result is identical to removing the pin entirely as it is too short to catch on the cylinder even when the key is removed.
Whatever solution you decide to implement, when you are done make sure to check that all the pins sit flush with the rotor when you insert your key, otherwise the issue will persist - it is possible to have more than 1 faulty tooth/pin in a single lock.
Before you begin reassembling clean everthing and cover the components in grease, lube or graphite powder, so that the lock functions smoothly and doesn't end up binding. Insert the rotor into the cylinder (it only goes 1 way, so check that it can rotate the full 90°), place the cover on the front and carefully hammer the folds back over the cylinder. Slide the spring over the other end and secure the lever with the e-clip. Install it back in the car and enjoy your functional trunk for years to come
For as long as I've had this car, I've been opening the trunk via the lever in the cabin. At first even that wasn't working, but I fixed it with new hatch struts. The lock in the back of the car never worked. After changing out the struts in 2022, I sprayed it full of WD-40 but it didn't help. For some reason I just left it like that. Until now - I have decided to fix the damn trunk lock. (I'm gonna write this up tutorial-style like I did for fender rolling, in case anyone else is experiencing the same issue)
Start inside of the car by removing the central part of the plastic trunk trim. This will give you access to the latch:
Undo the two 12mm bolts and take it off to reach the lock. I don't have a picture of it, but it will be held in place with a single spring clip, you'll figure it out. Once you have it off, you're done on the inside of the trunk. Remove the center tail light piece and you'll be able to pull the lock out.
On the back, it's gonna have a small e-clip holding the lever in place. Be careful when you're taking it off, the top piece on mine broke very easily:
(this is still functional, but it was an unnecessary mistake)
After that, you can very easily wiggle the spring off of the rotor and cylinder. I simply spun it one direction until it was loose enough to be pulled off. Next, you will need to remove the cover off of the front. I did this by hammering a small screwdriver under the folds, where the cover is pressed onto the cylinder:
(there is one of these folds on each side of the cover, be gentle with them - you will need to fold them back down when you are done)
Depending on how messed up your lock is, after you have the cover off you might be able to simply pull the rotor out of the cylinder, but in most cases you will have to insert the key to get the pins aligned and pull the rotor out with the key in it.
This is where I found what was wrong with mine:
Even with the key inserted, the last pin doesn't come down far enough to allow for the rotor to be spun inside the cylinder. It was even more apparent when I got the rotor out:
This is the result of a worn key. The last tooth on the key is not long enough to push its pin all the way down, as it is worn-down and rounded off from its many years of service.
And since no one wants to get a new key just for the trunk, we have to fix this by either replacing that pin with a different one or taking it out of the equation completely. Be very careful when taking the pins out, they are spring-loaded and if they are mixed up, the lock will not function.
This is what each of the pins look like out of the rotor, they are more "gates" than actual pins:
The rectangle in the middle will be positioned differently from pin to pin, so that they match the peaks and valleys in the profile of the key. You can disassemble several locks (from parts cars and such) and collect many of these pins to have an inventory on-hand. If you can find a pin with a tight enough rectangle for your worn key to displace, simply put it in its place and reassemble the lock. There are not many variations of these pins, so this is a viable solution.
Another solution is to file the pin down until it no longer catches in the cylinder. As they are very soft, this takes about 10 seconds:
If your pin only has to be altered by a fraction of a millimeter, the lock might remain functionaly the same. In my case I had to shave off quite a bit of material, so the result is identical to removing the pin entirely as it is too short to catch on the cylinder even when the key is removed.
Whatever solution you decide to implement, when you are done make sure to check that all the pins sit flush with the rotor when you insert your key, otherwise the issue will persist - it is possible to have more than 1 faulty tooth/pin in a single lock.
Before you begin reassembling clean everthing and cover the components in grease, lube or graphite powder, so that the lock functions smoothly and doesn't end up binding. Insert the rotor into the cylinder (it only goes 1 way, so check that it can rotate the full 90°), place the cover on the front and carefully hammer the folds back over the cylinder. Slide the spring over the other end and secure the lever with the e-clip. Install it back in the car and enjoy your functional trunk for years to come
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