Help with Bachmann Class 47 Running Problems

[Redford73]

Following regular derailments of my Bachmann Class 47s on my curent layout and realising it was an issue with only these locos I gained access to the wheels to check the back to back measurements and after readjusting the wheels on all locos and removing excess grease from within the gears and bogie I re-assembled the wheels only to find poor running on them.  

 

I was careful in replacing the bogie baseplate so that all the wheels were concentric and that the pick ups were in the right place and in contact with the wheels.  

 

All the locos run but at low speeds only.

 

Can anyone suggest what is wrong or has anyone had the same problem? 

 

[34theletterbetweenB&D]

Your other locos still all run at normal speed? (Ruling out that there is no coincidental layout power supply problem.)

 

It sounds like you have somehow made the class 47's bogies draggy - pretty uniformly - to achieve this result. It's pretty much guesswork, not knowing what you have actually done in detail. How was the degreasing of the gears performed for example? (Secondary question, why? Lubricant within the mechanism is not going to cause derailments.)

[Phil Bullock]

Most likely cause of derailments on Bacchy 47s in my experience is the life guards on the front of the bogie are a bit long and can foul on any uneven rail joints

 

Try trimming them back a bit

 

Phil

[Redford73]

Thanks for suggestions.

 

No all other locos run fine.

 

I was following instructions/advice in Nigel Burkin's book on Fine Tuning and Maintaining 00 Gauge Models in which he removes and replaces wheelsets.  This includes taking off the bogie baseplates on Bachmann diesels and checking the b2b and removing excees gunk/grease which is exactly what I did (There was quite a lot of gunk between the gears and I used toothpicks to remove it).  Perhaps I removed too much?  

 

Of the 4 Class 47s I did this with 3 are now slow running but I have noted that they do not derail anymore which suggests the b2b was the issue. They were derailing after coming off curves sometimes but more often on points even when running straight over them (i.e. when points were not engaged).   

[Phil Bullock]

Something else to check with Bacchy 47s

 

Are the brake actuator arms that come in the detailing pack fitted? If so check they are pushed fully home and not fouling on the bodywork as the bogie rotates - could contribute to what you describe but back to back is a continual issue with all RTR models.....

 

Phil

[34theletterbetweenB&D]

...I was following instructions/advice in Nigel Burkin's book on Fine Tuning and Maintaining 00 Gauge Models in which he removes and replaces wheelsets.  This includes taking off the bogie baseplates on Bachmann diesels and checking the b2b and removing excees gunk/grease which is exactly what I did (There was quite a lot of gunk between the gears and I used toothpicks to remove it).  Perhaps I removed too much?...

Pick the slowest (worst) of the slow runners. There's nothing to lose in revisiting the process you followed in an attempt to reverse whatever it is that is causing the drag. The problem in advising is that only you know what you did. It could be as simple as the bogie baseplates out of position and dragging on the track or wheelfaces. Remove the bogie baseplates one at a time and retest; etc.