Class 07 - Can't extract coupling!

[Phred]

I was looking for a Heljan 2915 Class 07 shunter for some time when I finally tracked one down at TMC for a comparatively good price. The loco arrived with one sand pipe buckled into a tight 'S' shape. As it seemed to be the last of its kind I elected to repair it, although it galls me to have to repair a brand new item straight out of the box.

The couplers were supplied in the accessories bag. I 'temporarily' popped one into the back NEM pocket so that I could add some load while running in, and it slipped home with a satisfying click from the locking tabs.

I want to use Kadee couplings on this loco but now I find that there is no way to extract the tension lock coupling as I can't access the locking tabs. Extraction by main force doesn't seem sensible.

Any suggestions gratefully received!

[Bigmet]

That is somewhat 'all concealed'!

Any better access to the rear of the coupler pocket if the body is removed from the mechanism?

If not, brute force it may have to be. In similar circumstances, I would spray a little GT85 (plastic compatible PTFE spray) into the pocket/coupler tails gaps a few minutes before the force is applied to allow it to work down to the latches.
Straight pull with pliers if you can get a safe grip on the body, or even better safely hold the model against a vertical stop where there is nothing to damage.
Or try with fine needle nosed pliers from the side, or a lever from above through the 'D', with a cylindrical fulcrum on the bufferbeam or cab rear.

Every model is different, do let us know what worked.

[End2end]

I've just checked my similar loco, a Heljan Class 14 'Teddy' but it has a different setup.
Perhaps you need to remove the screws from the baseplate to access them?
Failing that, I wonder if there is a service sheet for the loco online somewhere?
Thanks
End2end

[Richard08]

I've just checked my similar loco, a Heljan Class 14 'Teddy' but it has a different setup.
Perhaps you need to remove the screws from the baseplate to access them?
Failing that, I wonder if there is a service sheet for the loco online somewhere?
Thanks
End2end

I just re-looked at Sam's Trains video, as he pokes around inside, thinking the same. No go unfortunately.

[End2end]

Heljan have a live chat facility on their spares website.
Perhaps ask about the availability of a service sheet?
https://www.heljan.co.uk/spares
Thanks
End2end

[Bufferstop]

My guess is that the locating tabs are below the keeper plate. It should be possible to remove the keeper plate, at least far enough to reveal the ends of the NEM tensionlock coupler. It's probably a three handed job, one to hold the loco upside down, one to squeeze the tabs together with a pair of tweezers and one to pull on the loop with fine nosed pliers. Putting the loco in a cradle saves one hand, or hook the loop over a fixed hook or pin and pull the loco away.
[Edit] My cradle, (two of them actually) is the stiff foam packing that protected the ends of a keyboard within the packing of a computer. You could make similar from some thick foam sheet glued together with Copydex.

[Phred]

Bigmet wrote:
Any better access to the rear of the coupler pocket if the body is removed from the mechanism?

I break out in a cold sweat at the thought of opening up most locos (not to mention re-assembling them) and this one has more pre-fitted fine detail than I’ve ever seen, despite a bag full of extra accessories. It’s a lovely looking thing, but I don’t feel confident enough to take it apart.

Bigmet wrote:
try with fine needle nosed pliers from the side, or a lever from above through the 'D'

Sadly, there is barely a square millimetre that doesn’t have something breakable in the way. The coupler itself has hoses hard up against it.

Archimedes:
"Give me a place to stand, and a lever long enough, and I will move the world."

End2end wrote:
Perhaps you need to remove the screws from the baseplate to access them?

I wondered if those big screws might only hold the baseplate or be attached to something more complex but, looking at the Sam’s Trains video mentioned by Richard08 below, the coupler is still covered with the baseplate removed.

Richard08 wrote:
I just re-looked at Sam's Trains video, as he pokes around inside, thinking the same. No go unfortunately.

I just had a look at that video (I hadn’t thought about Sam’s Trains until you mentioned it) but as you say, no go. Looks like a nightmare to reassemble, anyway.

End2end wrote:
Perhaps ask about the availability of a service sheet

The paperwork that comes in the box has some quite detailed instructions but it is littered with warnings about damaging the delicate fittings (including a number of exclamation marks!)

Bufferstop wrote:
or hook the loop over a fixed hook or pin and pull the loco away.

I’ll try to find a place to grip the loco and come back to that one.

That yellow material under the loco is actually my version of a cradle. A pool noodle with a section cut out.

[Phred]

It's out!!

Taking into account all of your information and suggestions, I decided to try placing the loco on the workbench and holding it there with the index finger and thumb of my left hand applied to the only two places on the sides that weren't obviously breakable.

Then, using the tips of the same two fingers of my right hand, I grasped the 'loop' or 'D' and applied slowly increasing pressure. After a few seconds the tabs released and the coupler slid out.

Thank you all for your valuable input!

Well, I thought fitting the Kadee would be the easy part. Not so. Turns out that the metal 'hook' hanging underneath was too big and would have lifted the back end of the loco off the rails. So that had to come off.

While the extra metal was being cut off, the coupler flew across the workbench and the minuscule spring popped out. Against all odds I managed to spot it amongst all the worktop debris. I won't bore you with the details of re-installing the wretched spring with shaky hands and dodgy eyesight.

Went to pop the coupler into the socket only to find that it's both too wide and to thick.

Anyway, after a bit of surgery with the mini grinder it is installed.

The Kadee sticks out further than I would like but it moves easily from side to side, unlike the original which couldn't move at all.

Anyway, success! Well done team!

[Bigmet]

Good work getting the original coupler out! Sure to be useful information for other 07 owners.

I suspect the NEM coupler pocket is too low, (a regular Heljan failing) since the 'dropper' on the Kadee fouled the rails. This 'coupler pocket out of position' problem must be a fairly regular problem in HO, because height adjustable coupler versions are available. Unfortunately the American Kadee coupler doesn't offer a height adjustable option; so we have to do the job ourselves, filing and packing...