Tailgate lock replacement?

[RobClu]

After a month of freezing temperatures, first time I tried to open the tailgate it seems that either the lock or the barrel has broken. The key turns ok but the darn thing remains resolutely locked (suppose it could be worse!)

1- Am I right in thinking I need a new lock?
2- How do you change it when you can't get the door open?

Any advice gladly received!
Cheers,
Rob

[kevtherev]

probably needs soaking in plus gas
tried squirting some in?

[pocolow]

After a month of freezing temperatures, first time I tried to open the tailgate it seems that either the lock or the barrel has broken. The key turns ok but the darn thing remains resolutely locked (suppose it could be worse!)

1- Am I right in thinking I need a new lock?
2- How do you change it when you can't get the door open?

Any advice gladly received!
Cheers,
Rob

You could get to the lock by taking off the interior panel of the tailgate.....and give it a little persuasion.....

[Syncro G]

Humm, posh German Westy; Does your van have central locking by any chance? If not skip to the bottem, or read the following for your amusement, doubtless someone might find it useful one day if it gets edited for spelling (probubly a lot) and wiki'd?

If you've got central locking, first up can you hear the motor wering in the tailgate running when the cab doors are turned? If not thats your first problem. Wires might have got damaged where they bend in the hinge area if the other doors work, you have a motor/wireing fault at the cab end if none of the motors work properly, they might of frosen, the cab ones are prone to letting in water! (there was a motor rebuild thread a couple of years ago if it still exists).
The motor should slide a yoke along a shaft (again cold might not help). When working properly the motor should slide it from eather end, this is what its trying to achive when its working properly...
When the barrel is in the lock/unlock with central locking position (horisontal key slot)

Yoke in C/L unlocked position, barrel in unlock on C/L position, note the arm should press the yoke.

Yoke in C/L locked position, barrel still in unlock on C/L position, arm can't press yoke so door is locked.

When lock barrel is in always lock vertical position...

Note it doesn't matter which end the yoke is slid to, the arm will always miss it so the tailgate will always be locked regardless of C/L state.

Lock barrel in force unlock position (key fully clockwise, key shouldn't be removable if it all nice and unworn)

Note it doesn't matter which end of the slider the joke is at, it'll always press the joke so always be able to open the van regardless of C/L state.

Incertently at the bottem of the picture you can see the bolt hole where its mounted to the van on the bottem of the tailgate (undo all the bolts holding the latch on the bottem of the tailgate, reomve that and you should be able to just pull the barrel unit out from the inside, remember the motor rod needs unhooking too, might be easyer to take the motor out first). On the top side of the barrel is the long arm that presses on the actual door latch unit. Just above the slider rod on this arm you can see the plastic clip the motor rod conects to.

So then, thats how it should work, what when it doesn't? I think it tend to be the slider doesn't always sit and stay at the extremes of its travel. Somewhere in the slider mecanisum I think there is a detent spring sort of arangement that makes it locate at eather end, probubly gets week through age so it can jump out of place easilly. I think it does this becuase the yoke/arm wares slightly so they can help push it out of place. Only thing I can recomend is trying to file the detent grove a bit bigger if you can find it or maybe trying to build back up any worn away matereal on the yoke/arm somehow - seems to be a fairly tight tolarance in there of how to get it to slip. I took the above photo when I retumbled it for my van but I think it must have had history of playing up in what ever van it came from as someone had rapped insulation tape around the slider so it was fixed in the c/l unlocked position - efectively converting it to a standard lock (you would have to unplug the motor if you do this) - makes it useable but defeats the point of central locking. Usally when mine fails to unlock, if I lock and unlock the cab, it usally works if I then use the horisontal key position, so thats what I always leave it in (usally only fails to open when someone messes with the key anyway). I think the horisontal postion seems to be the most reliable and by the look of it is least likely to exert a force in the direction that could slide the yoke, though that could vary with ware in your perticular lock. If you try the fileing the detent thing then let me know how you get on. I wish you luck as the central locking style barrel is obsolete I belive.


If you don't have C/L, I'd have thought the possable failure areas would be... (which are still aplicable to C/L systems of course)
1) Defective latch unit (not barrel!) which will probubly make opening the tailgate really fun for you
2) Arm on the end of the barrel is badly worn/broken (this arm is different to the C/L type pictured, but does a simular job, I suspect is less prone to ware)
Those are probubly fairly unusual though. The arm is only held on with a tiny roll pin so swap it off another barrel of the same type (ie non C/L barrel) so your original key still works the lock. When the pin and arm is out there is nothing to hold the lock barrel in so its best to leave the key in when you do this, it stops the tumblers falling out if the barrel is removed from the housing.

[RobClu]

Hi all,
I've already tried the WD40 route but no luck.
We don't have central locking so Glen's suggestion sounds good - I'd like to keep the same key.
Is there any more you can tell me about how to fix the arm? Do I need to get a replacement unit from a scrapper?

Ta

[RobClu]

Fixed!
Got the tailgate door card off.
Managed to move the yoke sideways with fingers to open the door.
Once door was in horizontal position, soaked lock barrel with lubricant and worked it all backwards and forwards.
Now seems back to normal.
Phew!