Bachmann E4 trailing wheels question

[spikey]

Well, everybody said it's a lovely loco, and indeed it is. I've managed to get myself a very nice secondhand pre-owned one and am generally very happy with it. However, there's always an "however" ...

 

This one has tendency to occasionally derail the trailing wheels on pointwork when proceeding in a forwards direction. It doesn't seem to be prone to it when running in reverse. Track is Peco code 75 and back-to-backs are 14.40 - 14.45 for the drivers and 14.6 for the trailing wheels.

 

It tends to act up on one or other of two curved points which I have yet to confirm are laid dead flat, but my only other 0-6-2, the Webb Coal Tank, has never exhibited the same behaviour. Is my problem in any way characteristic of this model? Is there anything I can check for beyond back-to-backs and track alignment? This one's a lovely runner and it's cosmetically 100%, so I'd really like to persuade the trailing wheels to behave themselves consistently ...

[Nile]

I'm sure this problem has cropped up before in this topic:

http://www.rmweb.co.uk/community/index.php?/topic/81251-Bachmann-e4/

A poor looking design to me, the axle can end up at an odd angle to the rails.

[GreenGiraffe22]

Mine does it all the time, I've learnt to just accept it, sometimes it rights itself again, sometimes it just continues around the layout derailed without hindering the performance of the loco

[34theletterbetweenB&D]

...A poor looking design to me, the axle can end up at an odd angle to the rails.

 It is so. This design was first seen on their first 0-6-2T, the 56xx. Clearly too few have complained over the years or Bachmann would have dropped it for the more sensible and generally reliable pivotted pony truck arrangement, which they execute very well lightly sprung on numerous of their models.

 

Enough of complaint, what is to be done? There is a simple and fully reversible mod. if your layout curvature permits (I haven't tested this below Peco's medium radius point or 24" radius plain track, but on these it works well).

 

Cut two small pieces of black plasticard, cement to keeper plate to restrain axle from swivelling. I placed two pieces of 20 thou ahead of the axle one each side. The 56xx had a very generous 6mm of side play as received, of which about 1mm was lost to the plasticard restraints, unlikely to be very restrictive.

[spikey]

... There is a simple and fully reversible mod. if your layout curvature permits ... Cut two small pieces of black plasticard, cement to keeper plate to restrain axle from swivelling. I placed two pieces of 20 thou ahead of the axle one each side. The 56xx had a very generous 6mm of side play as received, of which about 1mm was lost to the plasticard restraints, unlikely to be very restrictive.

Ahah! The answer to a maiden's prayer. Thank you kind sir. I'll give that a whirl ASAP.

 

Meanwhile, I note that the box mine came in is stamped 150129, which I guess is January 2015. Does anybody know if there was a later batch, and if so, whether those currently in the shops new will have the same abomination at the back end?