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Subject: Procedure to remove ignition lock barrel and get at tumblers Author: oberon as Jerome : member since January, 2006 : 613 posts Posted on: 2007-03-16 18:40:08

As promised, here is my write-up on how to remove the black cap from the E34 ignition key barrel (some people say cylinder instead of barrel).

Remove the barrel from the ignition

First off, you'll have to remove the barrel from the ignition. It seems some people have great difficulty doing this, and I can understand why - it is quite tricky.

You have to insert a small but rigid piece of wire (or something similar) into the small hole next to the key on the barrel. The key must be turned to the first position beforehand.

Figure 1


You can see the small hole in figure 1. You can also see a rectangular pin on the barrel body protruding slightly. This is the pin that you are aiming to retract by inserting the wire and this pin is what holds the barrel in place in the ignition.

Figure 2


In figure 2 you can see I've inserted a small (1mm) drill bit into the hole. Note how the drill bit doesn’t go in straight. This is VERY IMPORTANT - whatever you use as the wire/pin can’t be too long (if it can’t bend) because the angle prevents it from going in with the key inserted if it’s too long.

I'm afraid I can't give you any sure-fire tips on how to easily release the barrel. It requires some wiggling of the key to get it to exactly the correct position, and some wiggling of the wire/drill bit to get it right. I noticed that at the point that the thing releases, you can feel the wire/drill bit has moved/released something inside the barrel. To then get the barrel out you pull on the key to extract the barrel.


Get the black cap off

Now we get to the part you've all been waiting for - how to get the damn black cap off!

Unfortunately this does require cutting/grinding away a part of the black cap. You will have to either clamp the barrel into a bench vise and use a hand-held grinder or other rotary cutting tool able to grind aluminium, or use a bench grinder (the grinder is fixed to a bench).

Figure 3


Start grinding on the OPPOSITE side of the barrel to where the white plastic shaft is. There is a locking ring holding the cap on. The ring has about a 1.5cm "opening" in it where the white plastic shaft is, and we want to grind somewhere away from the ring ends.

Figure 3 shows what a successful grind looks like. Grind on the fattest part of the cap because that's where the locking ring resides - you need to expose the locking ring. It's ok if you grind the ring a bit too (it's unavoidable really) but don't grind through it completely! Stop waaay before that. You're looking to get enough of it exposed to be able to press down on the ring through the hole with a pair of long-nose pliers.

Now you need to rotate the cap around so that the newly-ground hole is on the side with the white shaft.

Figure 4


You can see in figure 4 that I've rotated the cap so that you can see one end of the locking ring through the hole. This is what you want. Perhaps rotate it slightly more away from the white shaft than in the picture, so that the end of the ring just disappears. You need to compress the ring inwards so that it releases from the race inside the cap. I found using long-nose pliers (or needle-nose pliers) was effective. I gripped with one side of the pliers pressing down on the exposed ring and the other end was just inside the keyhole. As I compressed the pliers I also levered the pliers to pull the side of the cap away from the barrel body. If you've pressed the ring down enough then the cap should pop off just slightly on the side you're gripping on. Remove the pliers and twist the cap at the same time as you pull it off. This should pop it up off the rest of the locking ring.

Figure 5


In figure 5 you can (hopefully) see the race on the inner edge of the cap, which is pointed to by the arrow.

Figure 6


Hopefully you have gotten to the point shown in figure 6 now!

Figure 7


Now you can more easily see the locking ring and how it is sprung to behave like an "inverse c-clip".

Figure 8


And here are all the pieces. You can see I've pulled out the internal tumbler barrel. I'll get to that next.


Messing with the tumblers

To get at the tumblers (the little inserts that are "coded" to your key to make the lock work) you have to insert the key and turn it clockwise to approximately the first ignition position. You then pull on the key and you'll feel/hear a click as something releases. This is the point at which you think "Oh crap. Am I going to be able to get this thing back in?"... Hehe - no worries. I was the guinea pig and figured that part out so you don't have to! I'll get to it later, so you can continue to pull things more apart here.

There is a complex arrangement of grooves and lands that determine how much you can turn the key where. To get the inner tumbler barrel all the way out, you have to fiddle with turning the key a bit, then pulling a bit and so on, until you've got it past the first centimetre (1/4 inch) or so, then it comes right out.

I can't give you much detail on how to fiddle with the tumblers themselves because I didn't need to do that myself. I actually took this lock barrel to a locksmith and he did the grinding and tumbler swap to match it to my door key. This is how I learned how to go about getting the cap off.

There are some other articles on the web about messing with tumblers anyway, so I'll leave it up to you to sort that out. The only advice I can give is DON'T remove the key with the inner tumbler barrel removed (unless you know what you're doing) because if you do you may well be searching for tiny tumbler inserts half way across the room.


Putting it back together

To get the tumbler barrel back in the outer barrel body you have to align it so that the large groove on the tumbler barrel (on the opposite side of the tumbler barrel as pictured in figure 8) matches up with a protrusion on the inner edge of the outer barrel body. It happens to correspond with the position you need to have the key in when you removed the whole barrel from the steering column originally.

Unfortunately I don't have any further pictures of the inner tumbler barrel removed. At this point I was more concerned about figuring out how to get it back in properly! I had a problem you see... I couldn't get the tumbler barrel back in completely.

Figure 9


To get the tumbler barrel in properly you have to turn the key around a bit to get it past the last centimetre (1/4 inch) like before. Figure 9 shows the furthest you'll be able to get the thing back in, as well as the key position when you manage this. If it seems to stick and not go in as far as in figure 9, then pull the thing back out a bit and turn it around until it is like figure 9. This part is a bit fiddly.

But we're not done yet – it's not in completely, as you can see if you compare figure 9 to figure 6.

Figure 10


Perhaps a more telling picture is figure 10. This shows the bottom of the barrel. You can see the bottom of the tumbler insert is not flush with the outer body. It's supposed to be, so what now? You have to "un-click" the click you heard when you pulled the tumbler insert out earlier. Huh? But how? This is what I spent 15-20 minutes trying to figure out. To keep a long story short, I'll skip to the punchline...

Figure 11


What's this? A hole just waiting to have something inserted into it?

Figure 12


YES! My trusty 1mm drill bit does the honours.

Firstly insert something appropriately sized (like my drill bit) and press in the direction of arrow 1. Then while still doing that, press the key inwards as shown by arrow 2. Voila!

Figure 13


Figure 13 shows what you were pressing on above. There is a sprung pin thing on the tumbler insert, which you have to depress to get the tumbler insert to go all the way back into the outer barrel body.

Now that the tumbler insert is properly back in place, turn the key all the way back to "off" (counter-clockwise) and you can remove the key.

Figure 14


Oops, what's this? The little shiny cosmetic cap thing has come off. No worries, it can only go back on one way (you can see the 2 locating pins). You probably noticed it had a tendency to slide up the key a bit when you were busy earlier anyway.

All that's left now is to put the black cap back on. I had pulled the locking ring off earlier to take the figure 8 picture, so I had to replace the ring. I imagine you needn't remove it to remove the tumbler insert, but if you did then you'll obviously have to put it the ring back in place now.

It should be a fairly simple task to pop the cap back on over the locking ring. Fit one side over the ring then compress the other side of the ring inwards while pressing the cap back on and it should snap easily into place.


Putting the barrel back in the ignition

In order to put the barrel back into the car's ignition, you have to get the retaining pin (referred to in figure 1) to depress so that it's flush with the barrel body. This is fairly simple because you can press it down with your thumb, but the key has to be inserted and turned to the first ignition position first. Unsurprisingly, this is the position you removed the barrel in.

Figure 15


Here you can see how I grip the barrel. The pin is under my thumb and I press down on it as I turn the key clockwise into the correct position. As it gets to the right position you can feel the pin go down. Turn the key as far as it will go while you press down on the pin. With you pressing on the pin, the key is prevented from turning any further than the exact position you want it to be in. Hooray for German engineering

Now you need to line up the barrel roughly in the same orientation as you extracted it initially and insert it back in to the ignition. It doesn't have to be exact because as you turn the key back and forth after inserting the barrel it should self-locate. I think it's fairly fool-proof, but if things aren't properly lined up just turn the key back and forth a bit (which should actually only turn the barrel itself until the end of the barrel has mated up correctly) until things click nicely into place.

Figure 16


Here you see my barrel re-installed. The yellow arrow points to where the cap was ground down. As you can see it's hardly noticeable, and if you rotate the cap around so that the ground bit is towards the front of the car then you won't see it at all. You should be able to rotate the cap with your fingers even with the barrel installed. The key may have to be removed first and oily fingers will make it hard to get a grip on the smooth cap surface. But honestly I doubt it makes any difference which way the ground bit is pointing because it's so hard to see.

And that's it!

PS. If you REALLY want to have a pristine black cap then I believe you can get them separately from BMW, but after 2-3 years the cap will look as scuffed-up as mine does, which looks almost as scuffed as the original 11 year old one it replaced.

Jerome
1992 525iA
Cape Town, South Africa

• Procedure to remove ignition lock barrel and get at tumblers (pic) - Jerome 2007-03-16 18:40:08 (5668 views)
  • Re: Procedure to remove ignition lock barrel and get at tumblers - bissellh 2007-05-12 01:16:44 (364 views)
  • Great detailed description, Thanks!! (nt) - beezer02 2007-03-23 22:41:57 (285 views)
  • Fantastic writeup - bobbert 2007-03-16 19:30:38 (266 views)
    • Re: Fantastic writeup (url) - Jerome 2007-03-17 04:27:45 (276 views)
      • Re: Fantastic writeup - Shayne 2007-03-17 11:58:54 (240 views)
  • Comparison to my old lock barrel (pic) - Jerome 2007-03-16 18:59:35 (447 views)
    • exactly what broke on mine!! (nt) - bikeman 2007-03-23 21:11:47 (337 views)