'bolt' in middle of cylinder lock is a different size

[luckysh0t]

While I was out my flatmate lost his keys and needed to get the lock removed from the door. The locksmith replaced the ~13yrs old ruko cylinder turn lock (oval shape) with a Sterling cylinder lock (with no turning knob on the inside). I like the handiness of the inside turning knob for easy locking so I went out and bought a Yale cylinder turn lock. The issue is what I would call the 'bolt' in the middle of the lock that engages with the actual locking mechanism that sticks out into the wall - on the old ruko lock it was a smaller shape than what is on my new Yale replacement. The Yale one doesn't engage with the locking mechanism when it is turned - it appears to be too big. I think the locksmith's Sterling replacement had a similar issue and he removed the bolt from the old ruko lock and put it on the Sterling one then fitted that to the door - the old ruko lock is cut in half as a result.

Here is a picture of my new Yale lock with the outsized bolt in the middle. How can I take the old bolt off the Sterling lock? Just take a hacksaw to the lock? Then how do I replace the bigger one on the Yale lock with it?

[ARF-GEF]

You can replace that, they are often (but not always!) interchangeable. If you do it properly and it goes smoothly it's easy but if you make a mistake that can easily make the lock unusable. It depends on the lock type and the cam type you have and the one you need.

You should weigh how important that is for you and how much risk are you willing to take.
So once again you have a chance of screwing things up to a level where you can't mend it yourself!
Now if you decide to continue you will have to remove the 2 cirlicps (or C-clips) at the 2 sides of teh "bolt" (called the cam I believe). With that you free up the plugs to be removed. With the correct key inserted you pull the plug out a little bit (1 mm or so) and do that at the other side. Warning: if you pull it out too much insides might pop out or fall apart.
Some types of lock require the plug to be turned a bit so that nothing can get stuck. That is maker and model specific. (Before you do it: DO NOT ever post pics of your key online.)
After you pulled both plugs out a little bit the cam in the middle should free up. Now there is a thingy inside the plug which is also usually model specific so after you exchanged the cams the thingy must go inside again. Carefully observe how it is originally you will have to put it back exactly like that.
After that push back the plugs, test the lock for any problems put back the C-clips and happiness
I would advise you to do a bit of research and only start it if you have understood the working and mechanism of Euro profile locks (especially the cam area).

I personally would not really encourage you to do that yourself, ask a local friendly lockie, they will probably do it for you for a really small fee.
Another point to consider: most of the Euro profile lock can be converted to have that turing knob thing at one side.
The professional solution would be to convert the lock cylinder in use to have the turning knob on one side.

BTW I think changing from Ruko to Sterling is a considerable downgrade.
But hopefully other lockies with more local product relevant experience will chime in

[luckysh0t]

Many thanks for that full and plain speaking explanation. I'll have a look at it but I'll probably convert the existing lock if it's an easier job. It's an internal door in an apartment block so security wise I'm ok even if my flatmate did cheap out on it...

[ARF-GEF]

Yeah conversion is much more safe, and it shouldn't cost you too much. Hopefully your local lockie has the right knob to convert that type.