QUOTE (Noggins Friend @ 2 Jan 2009, 10:40)
<{POST_SNAPBACK}>I recently acquired "Great Central"....
Congatulations on the purchase, they are nice locos are they not?
QUOTE ......The problem seems to be that the pony truck under the cab prevents the full weight of the loco bearing on the drivers. Is that a correct diagnosis and can anything be done.
To me the problem is actually the other end and it's the front bogie that is bearing too much weight.
Put the loco on a flat surface and push down on the rear of the cab and see how much it lifts the front drivers, now push down on the front bufferbeam and see how little the rear drivers lift.
The solution is fairly simple but may cause you to pull your hair out.
You have to remove the body and take the front bogie off, this requires a screwdriver on both top and bottom of the chassis, three hands and eyes out on storks.
Remove the coupling pocket. You may want to add some more weight to the front bogie as it will now be very light with no assistance from the loco weight to keep it on the track.
You may need to file the top of the bogie mount now to allow more verticle travel depending on how sharpe the transition from flat to gradient is on your layout. I didn't need to because I have no graidients and now the A1 will haul a mix of 10 Bachmann Thompson and old style Gresley coaches.
Reasembly is more frustrating than taking it apart, be patient and get somebody to lend a hand so you don't throw it at the nearest wall.
Hope that gives you some pointers
Andii