Trunk lock seized.

[gf]

Hi everyone! Earlier this year my boot lock seized. Vacuume locking was disconnected years ago to the boot. Key won't turn! Called a dozen locksmiths including "specialist automotive locksmiths none were willing to touch it!!!!!!I went and looked on another forum they recommended drilling to the right of the barrel 5mm, 32mm up from the bottom of the barrel. And 35 mm deep and inserting a coat hanger wire with a 90 degree bend facing towards the barrel. So I did this and " pop! The button pushed in but the lock is still seized and boot shut!!!!! I'm guessing the latch to the boot has physically disconnected from the locking mechanism. Any ideas for a plan B?

[daantjie]

All I can say is good luck unfortunately. I once had to break open a trunk at the junk yard. Took me a good hour. That latch is seriously over engineered like only the Germans can do.  Was worth it though, found all 4 suspension blocks in the trunk. Was a good day

[rumb]

There is a piece at the back of the lock behind the button that rotates. An arm of sorts has to line up with the actual release. this arm needs to rotate counter clockwise to be in position. If it is still connected, the rod from the vacuum moves this.  otherwise you need to get this arm rotated, then when you push the button it will unlock.  if the button moves freely, it is not aligned. I would make a small hook on the end of the 90 degree wire bend and use it to fish around for the arm.

I will try and get a photo of the back of the lock so you can imagine what you are trying to catch.

[gf]

Sounds like it's going to be a challenge! That photo might just save me rumb!

[rumb]

here are pictures of the lock backside, notice how the arm can be in 2 positions.  If you have your key, try turning it all the way CC and pushing the button in.  otherwise try and figure out how to get the arm pointed straight down.  the end of the arm is what pushes against the actual latch.

[marku]

Happened with the PO of mine and he drilled, with a big dia bit, right through the lot in the centre of the barrel and into the boot. Made a bit of a mess of the interior panel but covered by the trim. Apparently drove for quite a while opening the boot by literally sticking his finger in. Was like that when I got the car but now has a replacement lock which works fine.

[gf]

Ok so I've tried all suggestions, now it's time to bite the bullet and either drill out directly into the barrel or bash it out somehow with a slide hammer. But there's one problem. I've struggled to find a replacement barrel before I do this. I can find the other parts though. Might have to call the stealership!

[marku]

As I said previous owner drilled right through the lot and when I got the car you could only open it by sticking finger in the hole and actuating the catch. As long as you keep the bit centred its OK but he also drilled through the catch mounting as well. Had no trouble getting a replacement from a breaker and a key cut. Fitting it was odd though. Even though it had the part number on and 116 it would not fit the trim. Just a bit too big had to carefully ream it out but it has worked without problem for a couple of years now. Did MB change the spec on later cars?

[rumb]

On my car someone drilled a hole about 2" to the right and lower than the lock, presumably to get the latch unlocked.You would need a 3/16" or thicker rod to exert enough pressure to push the latch inside.  probably need to bend it some to get it to the correct spot.

[gf]

I looked on e bay and finally got the parts. I think the latch is compatible or the same as used in an R107. I'll keep you folks posted if I have any similar fitting issues.

[gf]

Ok I finally got the lock open and replaced. Lessons learned- get a professional grade makita power drill, most of the $150 hardware shop drills are almost useless against this hardened metal.
The initial hole I was drilling would have been correct, but what happened was the lever from the vacuum actuator had disconnected at the locking mechanism, jamming the latch and being directly in front of the hole I had drilled. Hence not feeling the latch with the coat hanger wire. Ended up drilling 3-4 20mm holes everywhere till I found an unobstructed spot to the latch. Looked like it had been to the battle of Kursk and back.
So the latch mechanism had not failed at all.
It appears there's two types of lock for these cars. One for vacuum locking and one without, as there is no lug to attach the lever from the actuator on this new one.
Not sure all this makes sense I'll try to post some pictures soon.

[marku]

The replacement lock I got from a breakers had the 116 part number on it but did not actually fit. The barrel was a bit to big and so had to ream the opening. Why it was different I couldn't figure out but had no difficulty with the central locking.

[gf]

Marku, I know the latch on a w116 is common with some other models so I wonder if the barrel was the same situation? Visually they look the same on a R107. Yet another mystery for the w116 detectives out there!

[marku]

Not only did it not fit but when I took it to the locksmith and told him the year and what it had come out of he said couldn't have as the key was laser cut. Had the 116 part no on it.

[gf]

That is weird!