As a cheaper alternative to rebuilding my fleet of AC locos I have started a program of simply rebuilding the existing motor bogies using new motors similar to the ones found in CD ROM drives. I have found a supplier on the Internet that sells replacement motors and the all important drive pinion. The ringfield motor fitted to the Hornby class 86 is very easy to convert its just simply a case of stripping down the bogie then removing the armature, magnet and bearing from the old motor. The replacement motor just needs some packing around it to hold it in the old motors shell. I have found that a piece of cable tie is a perfect fit for this. The replacement pinion is practicaly the same size as the original fitted to the old 3 pole motor (the 5 pole is different) so once the new motor is in place its just a case of refitting all the drive gears, etc. The replacement motors run on about 6v so you will have to fit some method of dropping the voltage ie. diodes, resistors, etc although I think if you use DCC you can just re-program the decoder.  

The Lima class 87 motor is slightly more involved as you have to carefully remove the plastic surround that fits over the drive pinion. Also the mounting method is slightly different as you may have to mount the new motor slightly off centre. The only real difficult loco I have converted so far is the class 89 as the new motor was catching the flange on the centre wheel. To get round this I simply ground off the wheel flange.

All in all the conversions have been worth the effort as the locos are now a lot quieter and better at slow speed running although I would recommend fitting extra pick ups. And at £1.75 per motor compared to £££’s for a complete replacement chassis …..