Dear Forum,

As I have seen from a lot of threads here and in other forums, there seems to be a big problem with the older Doblos rear door locks. In my particular case it is the Split version (just inherited from my father-in-law).

I did not find any solutions to my problems so I have decided to start this thread and am really looking forward to your input.

The Problem(s):

Firstly the lock chamber itself seems to be "stuck" I am not even able to enter the key fully. The way it looks to me is as if this is simply stuck due to a build up of lime-scale from bad weather (not entirely sure though). I am also assuming that the slot for the key should have a little metal cover which slides to the side when I enter the key just as it does on the side doors. In this case, I am sure that the parts are simply stuck as the slot is always "open".

The question is how I can loosen this up? Simply spraying it (lube / WD40) hasnt seemed to help. I have also not yet found out how to remove the entire handle / locking unit and am not even sure if this is going to help me.


The second problem I have is that my father-in-law had the central locking disconnected from the rear door as he was having problems with the locking mechanism itself. Of course I can only check this locking mechanism problem once I reconnect the central locking. (There are enough forum entries into fixing the locking mechanism itself). But how do I reconnect the central locking to the back doors.

Looking forward to all of your input.

Regards
Scott

Hi Scott, locks usually seize up as keys not used due to central locking, if you can remove handle sit it flat so you can fill it with freeing oil and leave to soak,gently work the key in/out and try to turn, they do get very seized, If you sort out central locking it won't matter as will lock/unlock with that.
The central locking has probably been disconnected from the actuator in passenger rear door. Remove inner handle(spring clip between handle and panel), remove screws from panel,ease off panel has plastic plug retainer behind panel. Remove inner handle mechanism, 3 Allen keys from memory and should see plug and actuator,reconnect. There is a pin with a small spring on it in the door lock mechanism, this seizes and should move freely left/right when locking, free up so returns on own by its spring pressure when locking. This is why central locking is disconnected as seized pin doesn't slide and it thinks rear door unlocked so releases locking on other doors, disconnect actuator and other doors will lock with central locking. Hope this helps, John.

Thanks Liftex for the information..... Having removed all panels on all 4 doors I found the disconnected wire actually in the rear door which I am having the problems with - makes sense really

Now surprisingly the problem with the pin is the opposite to what most people report.... The pin now moves a bit more freely but is not able to return back to the original position (looking at the inside of the door the pin moves to the right (meaning the door is locked as far as I am aware) but the spring is too weak to return the pin to the left. I have been covering the pin with WD40 and moving it from side to side and spraying it with a "bike chain spray" hoping this provides enough lube.... Maybe I am just using the wrong thing.... Any suggestions?

Either way, having reconnected the central locking, I am able to lock the back door. However, unlocking is of course a problem. I am guessing this is what is causing the central locking to "re-fire" on all other doors (I turn the key, the locks fire, and then fire again - as if one of the doors is open). This combination does however seem strange to me.

I have also managed now to get the key further into the lock on the rear door and can feel that the key is sliding in the chamber activating the "pins" better. However, either the last few pins at the back of the chamber are still not being pushed / moved as needed to recognise the key or simply the chamber is seized and not able to turn. Don't want to force anything but not sure how to go on with this.... WD40 and sliding the key in and out got it to at least accept the key better.

Looking forward to any suggestions on any of these topics....

Regards
Scott

If the doors lock then unlock again, the C/L "thinks" one of the doors is still open.

Undo the plug to the split doors and try to lock. If the system locks, the fault lies with the rear solenoid.

Mine was locking/unlocking, but while the solenoid was doing it's thing, the lock wasn't engaging due to the sliding section being gummed up with old solid grease.

There is a part that turns when the solenoid is activated to allow the handle to operate when unlocked, then when locked, it turns the other way to stop the handle from opening the door. This is the part that needs to be cleaned up.

I cleaned mine with brake cleaner & a wire brush, then applied copper grease & WD40 which made it more slippery than a banker with a 100,000 pound bonus.

That was last October and it's still working

Thanks for the info.... Will try and post a picture to get a bit more clarity though to some of the things you mentioned. Thanks again.

Chain lube is to sticky for the weak spring to overcome, if there is rust on shaft remove mechanism strip & clean, there is also a switch in one of the door catches
I spray with silicon then 3in one,

So it took a while, but here is an update with the situation:

- Got the complete handle incl. central locking mechanism out after drilling the round bolt (extreme measure but any other way just did not work.
- The barrel is still completely seized up but now that the handle is out I am hoping that I may be able to clean this up, and even get the barrel itself out to give it a good clean.
- Even though I am able to freely get to the pin to slide it back and fourth and lube it up good it still wont spring back into position on it's own.

I now have the following questions:
1) Anyone have any detailed instructions how to remove the lock barrel so that I can simply replace it if needs be?

2) Having looked at the sliding mechanism where the pin + plastic housing is situated, I can see that the holes are not central when the pin + plastic housing is not fitted (due to the large spring for the handle) - See image attached with green and red circles. The question is; is this only centered when the plastic housing is in place or should something else be positioning this? (Parts marked purple shows the plastic housing I am talking about and where this should be positioned).

3) My assumption to question 2 is that the plastic housing marked purple in my images attached is to position the parts. However, the question is, should the plastic parts itself be sliding within the wholes or simply the pin (highlighted yellow) be moving within the plastic part? In which case my pin is stuck solid within the plastic that I see no possibility of loosening it... Any ideas? I guess only the pin should be moving or what else is the spring there for??

Really looking forward to your feedback as I am so close to fixing this...... I AM GONNA WIN THIS FIGHT!!

*....hang on, there's a spanner in the works.....I can almost reach it... *


Mine was all in place, but I think the part you have outlined in purple/yellow may be the bit that was gunked up on mine.

It was (from memory) a part that moves with the solenoid. But mine was jammed up with old, solid grease.

Whatever part you see that attaches to the solenoid was what was causing the problems on mine.

Basically, it stayed put whatever the solenoid did, so was permanently unlocked.

Thanks for the info but the problem is solved.... For future reference here is what I found:

The yellow part I marked in the pics I posted above is a pin which for the most part of the middle is square and is a part of it's own and is separate from the plastic part marked with purple. In my case the plastic part was fixed solid to the pin and when activating the CL the whole part came out and wouldnt slip back in place.

I managed to seperate both parts by gripping the plastic part with pliers and hitting the pin to loosen it. Once I got the pin out I cleaned it up, carefully filed it down / scratched all rust and gunk off and lubed both parts up well.

The plastic part is, as guessed, there to align the parts mentioned in the previous post, guide the pin, and has notches so that the whole parts turns when using the handle.

The parts all run smooth and as expected!!

This means once I refit the handle I can only use the CL to lock and unlock the rear doors but I am happy with that.... Would still be great if anyone has any ideas how to remove the key barrel for replacement.

The next challenge I have now is to remove what is left of the bolt which I had to drill the head off of so that I can re-fix the handle. No ideas how to do this yet as the whole part moves when trying to unscrew it (long hexagonal bolt on the inside, and whats left of the screw on the outside, including a lip on the outside which is holding all of this onto the door)..... Will keep you all posted!

Don't know how to replace the barrel, i use to clean that part every year with wd40 and grease before it got to that stage, cost me a days work once.

The bolt you drilled out was a tamper proof, head breaks off when tight, the 2 I have done unscrewed after head was drilled off.
The lock is a junk design.

Quick update again... The handle is since re-fitted and works like a treat. The barrel is still jammed but as long as the CL works I am happy!! It was a pain in the ar$3 getting the hole free and quite drastic measures with the drill, but with a nut, bolt, spring washer, larger area washer and some loctite its as good as new.

My 2007 Cargo rear door CL actuator casting broke off from the handle assembly. I purchased a replacement via eBay at £50. I had to drill out the outside security mounting bolt to remove the handle assembly but exchanging the old for new was fiddly but straight forward. I packed the electric actuator each side with foam padding to reduce the vibration of the door slamming from fracturing the casting in the future.
PS I replaced the security bolt with a Allen key type long enough to extend through the the captive nut inside where I fitted a lock nut for security.
My picture shows the shattered casting.