How To: Replace w124 ignition cylinder barrel

[S9KSY]

21- Here, I have pulled pins out of the deep hole and latch mechanism. look how the ridge appears from the side.
It is this ridge that will hold the black metal cover (shroud) by sitting in its gutter.
In turn, the cover will hold the key cylinder barrel in place.

 

[S9KSY]

22- On your new ignition cylinder, mark your pin where it will clear the catch.
You will need to introduce about 2 cm deeper to lift the ridges holding the shroud.
23- Insert pin with the sharp edge of the bevel towards the periphery.
After clearing the ridge, then entering into the deeper latch hole, turn your DIT wire 180 degrees to pull the latch and unclip the shroud.

 

[S9KSY]

24- No picture for this step unfortunately.

However, it is an important step if this is your first time to replace a key cylinder as it will demonstrate:
a) The correct relative position of the shroud.
b) How the clever mechanism works.

In this step, you insert the shroud ON ITS OWN (without the barrel cylinder) until it clicks in place.
The shroud will be held in place by the 2 oblong ridges. One of them is marked with 3 short arrows in step #18.
To release the shroud, elevate the inside 2 latches marked with the 2 arrows in step #18.

 

[S9KSY]

25- Now, you need to understand and note which will be top and bottom of the cylinder barrel when correctly inserted without the shroud.

 

[S9KSY]

26- Put the cylinder inside its black metal covering shroud.
Insert the key and turn it to align the 2 holes with their slots.
You need to be holding the sides of the cylinder while turning the key.
Easier with fine fingers.

One of the 2 aligned holes/slots can be seen on the left.

 

[S9KSY]

27- Insert the barrel/key/shroud complex in the same orientation that you have established in previous steps.
Your DIY wires have to also be in place all the way through to the deep latches.
Depress the barrel cylinder and it will click in place.

 

[S9KSY]

28- Last step :bannana:
Depress the shroud which will finally realise its final position with a satisfying snap.

 

[S9KSY]

Thread completed.
I hope it will prove helpful
Thanks to all forum members who helped with information and advice which enabled me to write this thread
S9KSY