[spongebob]

I found with one or other of the heljans (26 or 27 not sure which) the bogey was quite tight at one end, the offending loco has been put away for a while now and I can't recall if I rectified it or just identified the problem. If i remember correctly the sideframes at one end fouled some part of either the body or chassis resulting in too little turn. It seemed to effect just one end and was partly due I think to the sideframes being a bit loose.
I'll dig it out and get back to you.

 

[spongebob]

Sussed out the problem I was trying to describe. I have a class 26 and 27 with the same problem, basically there is a lack of side to side movement in one bogey only (fan end in both mine). The bogey is fastened to the chassis by means of a plastic tube whic runs side to side and just sticks through the cast chassis, on the offending bogey this pipe has some flashing which needs cleaning off (presumably from the moulding process). A bit fiddly if you aren't too keen on stripping the thing right down but also on the other bogey the speedo drive looks worryingly close to the body lifting point(?) when put into a turn and maybe this can cause problems too.
I have also I suspect sprained the mounting points on a couple of bogey sideframes as there are a couple of white stretch marks on them but they don't feel too loose.
Curiously the 33 I have despite being the same chassis doesn't suffer from the problems but it may have been sorted before I bought it second hand.