Model Railroading > Atlas/ROCO split axle gears

Recently while running an older Atlas/Roco GP38 I noticed the thumping noise typical of a Proto split axle gear. So unusual to see this that i opened up the truck and found a split axle gear. Have never seen or read anything about this. Since I have about a dozen or so of these older locos from the 1970-1980s i now have something else to look out for. Repaired it using a gear from an older Atlas turntable motorizing mechanism. Seems Atlas used the same motor as their locos and some of the same gears. BTW i used several of these turntable motors to repower Athearn blue box locos to make everything speed compatable (pre-DCC). I have also had two cases of split gears on Blue Box locos which was a total surprise.
CR

Yep.   The Roco gears also split.   It is way way way rarer than the Proto gears which is almost 100%.    If you have a four axle Proto unit the Athearn gears are interchangeable and rarely but do split.    When I replace these axle gears, all brands, I take a numbered drill bit that just fits inside the plastic(or rather Delrin or like plastic) and ream out the axle until it fits easily onto the metal wheel.    There is so little torque being passed from the gear to the axle it can actually be almost loose and still work perfectly.    When you do that the chance of the axle gear splitting is next to zero.

ATSFSuperCap Wrote:
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> Yep.   The Roco gears also split.   It is way
> way way rarer than the Proto gears which is almost
> 100%.    If you have a four axle Proto unit the
> Athearn gears are interchangeable and rarely but
> do split.    When I replace these axle gears,
> all brands, I take a numbered drill bit that just
> fits inside the plastic(or rather Delrin or like
> plastic) and ream out the axle until it fits
> easily onto the metal wheel.    There is so
> little torque being passed from the gear to the
> axle it can actually be almost loose and still
> work perfectly.    When you do that the chance
> of the axle gear splitting is next to zero.
They used poor quality of material when they were made. Other plastic or ever what its called has been used in autos starting many years back with no problems. All the new gears dont have it either I doubt if  after reaming them out some dont slip there is no way to know for sure without putting pressure on that axle itself since they are all geared together.