Hi
I have on the workbench at the moment a Hornby R2585 West Country 34045 Ottery st Mary,
I've managed to get it running again, (it was in a very bad state) but the rear driving wheel set jumps at a certain point every revolution, the front two are unhindered, the rear axle is driven by the con rods from the front two sets of drivers.
Having taken it apart again I cant see anything which may be causing it, it sounds like the wheel sets have a flat at high speed, but they've just been replaced by new ones direct from Hornby, (the originals had moved on the axle and had lost quartering and the ability to stay in gauge!)
A small YouTube video is linked. its noticeable for what its doing at slow speeds yet noticeable by sound at high speeds.
the video is unlisted so only by clicking the link you should be able to see it.
at the top left (10-11) there is a small jump,
any ideas what may be causing this is greatly appreciated
Many Thanks