My top box is a Maxia E52 and my side cases are the E41’s with the keyless lids, but I’m hoping that most lock sets will be the same.
First step is to remove your locking mechanism by removing the 4 screws from inside the top box.
Next step is to remove the lock from it’s barrel by removing the circlip. Take care not to lose the spring and bearing that lies under the catch.
As you can see, when you put the right key in the lock, all the little tabs – or tumblers as i’ll call em - are pulled flush with the lock body enabling the lock to turn in it’s barrel. If you insert the wrong key you’ll still have a few tumblers sticking out that will stop the lock from turning.
Wrong key inserted - Notice some tabs sticking out - Lock won't turn.
What we need to do now is re-arrange these tumblers so they fit the profile of your side case key. With the key removed carefully pull each tumbler out of the lock mechanism with a pair of pliers. Be very careful as they’re spring loaded and the spring is minute. They’ll only come out one way and this should be pretty obvious.
Next choose a tumbler and fit it and a spring into the last tumbler slot – we’ll call this slot 7. Reinsert the key with just tumbler 7 in place and see if the tumbler sits flush with the lock body. If it doesn’t sit flush - as shown below - then remove it and try another tumbler. Repeat this step until you’ve found a tumbler that fits as flush as possible. If you can’t find one that fits perfectly flush then use the closest one. If you look carefully at the photo you should see the tumbler protruding in the bottom left of the picture. I should have photoed using a plain background!!
When you find one that fits put it to one side and then repeat the above for slots numbers 6, 5, 4, etc
Now insert all the tumblers and springs into their new slots. If you’re incredibly lucky you should now have a lock mechanism that’ll turn in the lock barrel with your side case key and with no further adjustments necessary. Chances are you’re not that lucky. Onto the next step.
If you look carefully at the lock with the key in place you’ll notice that a few of the tumblers are just sticking out preventing the lock from turning in the barrel. These tumblers need gentle filing so they become flush. Easy to do but a bit fiddly. Remove em one at a time, file, re-insert, re-check etc. Continue until all tumblers are flush and the lock should now turn smoothly in the barrel.
You're looking for this kind of finish.
Reassemble and the jobs a goodun.
Good luck.
And lastly - appologies. I'm crap at write ups, but I hope you managed to understand what I was trying to say.
...you must be pithed again