Coupling Rod Re-fit

[richard_barton]

 

Hi, hope someone can help. I have a Lord Nelson on which one of the coupling rods has come loose (as a result of coming off the track). The rod itself appears undamaged, and I still have the crankpin (I think that's right) but there's no way that I can get it back into the hole.

Partly because it's too small and I'm ham-fisted, but also it appears there is no means of retaining it once it's in.

Is it supposed to be a friction fit, or is there some other means of holding the crankpin in?

Appreciate any help.

Thanks

[Going Spare]

Was your loco made by Hornby or Bachmann?  If Hornby, the coupling rod is held in place by a hexagonal-headed screw; if Bachmann, it is likely to be a pin.

[Chrissaf]

TIP: As a newbie poster on the forum, just be aware that the 'Blue Button with the White Arrow' is not a 'Reply to this post' button. If you want to reply to any of the posts, scroll down and write your reply in the reply text box at the bottom of the page and click the Green 'Reply' button.

.

See also – further TIPs on how to get the best user experience from this forum.

https://www.hornby.com/uk-en/forum/tips-on-using-the-forum/

.

[richard_barton]

It's Hornby. And it's definitely a pin, the one on the other side is still in place and I have the pin, I just can't get it to stay in.

 

Richard

[96RAF]

Pull the service sheet if available to see if it offers any clues.

[atom3624]

Pity that it's the weekend - photos won't get authorised until probably Monday.

 

Where is this coupling rod / crankpin?

 

I've had a close look at several Hornby LN locomotive photos and all 'pins' holding the coupling rods into the wheels are the hex-headed screws they've 'always used', no change, so I'm suspecting it's somewhere else in the linkage?

 

As Rob says, the service sheet should help.

If it is one of the hex-headed screws, you need a driver which fits 2.5mm hex heads.

 

Al.

[Going Spare]

Unfortunately, the Lord Nelson is yet another loco for which, as yet, there is still no service sheet issued.

As Al surmised, if it is a pin involved, it must be within the valvegear assembly and therefore very small but will still need reinserting and, I suspect, the end turning over on the inside to secure the rods if there is any end left to turn over.  Disassembly of the loco and then the relatively fragile valvegear will be necessary and, on balance, a replacement valvegear assembly would probably be the easier option, if available.........  Hornby Customer Care may need to be contacted.

[richard_barton]

I'll try and take a photo if I can get it in focus. In the meantime, if you look at the photo on Hattons site https://www.hattons.co.uk/337761/hornby_r3634_class_ln_lord_nelson_4_6_0_851_sir_francis_drake_in_southern_railway_olive_green/stockdetail.aspx it's the rod connecting the rear-most driving wheel to the centre driving wheel. The pin has come out at the centre driving wheel end. I can push it in some way, but it won't fix in - I don't want to force it.

I suspect you;re right, the inside will want squashing out to make it larger than the hole, but I don't have any tools to do that.

Thanks for everyone's help.

[richard_barton]

Alternatively, can anyone recommend a good mail-order repair service that is working at the moment? The three I have tried have all shut down for the duration.

[atom3624]

So if I'm understanding thoughts, all 3 main coupling rod hex-headed screws are intact?

 

What has come out is where the coupling rod articulates just next to the centre driver hex-headed screw?

 

In theory, that should push in again, just 'flat' a little the other side enough to maintain articulation / movement yet keep it in place.

 

If it's difficult to replace, that means it might pop back in - need to fully remove the coupling rod first.

If too difficult, it may need another 'pin' which are available on Ebay, amongst other sites - I've seen them there previously - and push through, trim a little if needed, then flat just enough.

 

Don't enlarge the holes - could weaken the coupling rod.

The other option is to contact Hornby 1st to see what they say before you do anything.

 

Al.

[Going Spare]

If you feel attempting the repair is beyond you, have you tried Peters Spares (sales@petersspares.com) at Middlesbrough?  They offer repairs as well as supplying spares and appear to have email contact (but not the phone) still operating.

[richard_barton]

I've managed to take a photo, hopefully it should show the problem. The pin should go into the small hole just to the right of the hex in on the centre driver./media/tinymce_upload/5038c92f2afaf629451207c69c2e30a7.JPG

[richard_barton]

Unfortunately Peter's Spares are not, quote: "No we aren't I have had to send them home to minimise staff at the premises."

 

Thanks for the suggestion though - anyone else?

[Going Spare]

Unfortunately not: I suspect virtually all will be in the same position re Social Distancing.  The loco may have to be just a decorative adornment to the layout for the time being.

[atom3624]

That's precisely what I was thinking.

There have been pins available on Ebay for such things.

Others will have tried this and have advice I'm sure.

 

I would try it, but first, get hold of quite a few of these pins - can't be expensive - and practice with scraps of metal, drilled similarly, to get the correct 'squish' technique to hold enough, permit the articulation, and not interfere in the movement.

 

Al.