Exchange of views requested

I wonder if there are enough US-outline modellers in this forum to pass opinions on keeping Athearn diesels running well? I'm thinking of the robust 'blue box' series, which are easy to work on but known to have a few foibles. Here are my current issues in overhauling some long-serving units:

• The wheels are sintered and therefore slightly porous or pitted, causing them to pick up muck more easily. I have just ultrasonically cleaned mine; usually I use a scraper/wire brush combination. I'm too mean to buy after-market replacement sets to date.
• I did away with the strip steel 'bus bar' contact ages ago. Mine are all wired to the motor. Mind you, I never knew a bus bar to actually give trouble.
• What is the best lubricant for axle bearings? Whether these are on inside- or outside bearing trucks, they must still conduct current to the motor, so presumably the lubricant needs to be conductive. However, I think the recent use of commutator lubricant may have had the opposite effect.
• Some Athearns have a way of swaying from side to side on their truck pivots. Preventing this is presumably a matter of tweaking the pressed metal pivot plate so that it's dead flat but all such efforts on a U-36 have so far failed.

Any relevant tips or thoughts would be appreciated.

Hi Ian,
To take your points
 … thinking of the robust 'blue box' series, which are easy to work on but known to have a few foibles. 
Absolutely on all counts. Literally "Bomb Proof"  but I wish the motors ran better on my own controllers.
Here are my current issues in overhauling some long-serving units:

• The wheels are sintered and therefore slightly porous or pitted, causing them to pick up muck more easily. I have just ultrasonically cleaned mine; usually I use a scraper/wire brush combination. I'm too mean to buy after-market replacement sets to date.

I have a few NWSL wheel sets  but not all of my BB locos have them. It is a case of keeping them clean 

• I did away with the strip steel 'bus bar' contact ages ago. Mine are all wired to the motor. Mind you, I never knew a bus bar to actually give trouble.

While they might not give "trouble", that extra security of soldered contact will help your motor maintain a constant flow, as even an ohm can cause Athearn motors to seem erratic

• What is the best lubricant for axle bearings? Whether these are on inside- or outside bearing trucks, they must still conduct current to the motor, so presumably the lubricant needs to be conductive. However, I think the recent use of commutator lubricant may have had the opposite effect.
  

I use either Labelle Light or a special lube (which is actually a personal lubricant but sold by a hobby shop) I have been put onto over here in Australia and  it is OK!  

• Some Athearns have a way of swaying from side to side on their truck pivots. Preventing this is presumably a matter of tweaking the pressed metal pivot plate so that it's dead flat but all such efforts on a U-36 have so far failed.

I don't have a U Boat but check that there is not a burr on the metal plate in the pivot hole, using a drill bit to remove any rough edges but do not make the inner of the edge "bevelled" in case the pivot point is widened too much. 
 Check also for a burr on the lip of the metal strip and file it smooth as the frame can ride rough shod on the plate on the top of the bogie. If you can feel a slight edge running your finger over it, then file it flat. Similarly check the underside of the frame and check there is no "flash" on the frame where it sits on the steel plate. 

Any relevant tips or thoughts would be appreciated.
I do not have an original Athearn motor left running on my layout as I  replaced them all with Mashima motors a long time ago but as I said it was more a case of my throttle than the motor itself. I did have a very happy time of using Athearn motors with Ernst gears many years ago.
If you need, I will try to get a sketch done to explain the items I have talked about
Regards
Trevor

Much appreciated, Trevor. I will concentrate on the finer details of each point but we seem to broadly agree on strategy.

From Model Railroaders website in a question which talked about well lubricated motors not doing their stuff
Improving Athearn RTR/BB motors - Model Railroader Magazine - Model Railroading, Model Trains, Reviews, Track Plans, and Forums


1). Reduce the spring force on the motor brushes by cutting the springs or cutting the rear 1/3rd off the brush (the "Jim Six Fix").
2). Clean (and if possible, polish) the commutator including the slots between poles.  Start with a pencil eraser, then pick the slots with wood toothpick.
3). Lubricate the commutator with 2-26 Electrical Contact Lubricant.
4). Loosen the mounting screws and gently twist the motor ends while the motor is running.  What you're looking for is a "sweet spot" where the bearings are in pefect alignment.  You can tell when this happens by the sound and the motor speed.  Once this is attained, glue the motor parts together with some 5 minute epoxy, then gently re-screw it to the chassis.


Regards


Trevor

Hi there,
Just to add to the pool,
http://hackitup.railfan.net/athearn.html
and

Project Athearn Blue Box DCC install - Model Railroader Magazine - Model Railroading, Model Trains, Reviews, Track Plans, and Forums

Cheers
Trevor

Hi there again after several months,  I found this link which may be useful…
http://www.mcor-nmra.org/publications/articles/athearn_tuneup.html
Regards
Trevor