On the mogul that I am rebuilding, I have stripped it down to the frame. One thing I noticed is that the motor shaft has an excessive amount of play on the bell (comutator) end.
Is this normal for this type of motor?
Thanks in advance,
Nico
Yes, the motors in older LGB locos do have a lot of end to end play in the shaft.
I am not certain about the Mogul motor block, but on many other LGB motor blocks there is a small ball bearing at each end sitting in a cup that prevents the motor shaft lashing backwards and forwards.
Check and make sure they are there if they should be.
Also make sure the tiny little key pin on the brush end of the motor is seated correctly in the key way in the cradle.
Up until the late 1980s/early 1990s, Buhler motors had no thrust bearing and relied on the chassis to stop the motor shaft moving under thrust load. After then thrust bearings were fitted to the motor.
As Tony has stated, the four-wheel early clamshell drive blocks used a small thrust ball to limit motor shaft movement at each end of the shaft. Failure to fit the thrust balls upon reassembly would see early failure of the motor. The early Moguls (late 1980s) used a moulded top cover with an integral moulded thrust stop piece to limit shaft movement when used with early Buhler motors. The top cover is still the same on later Moguls but the motors should be thrust ball bearing fitted unless someone has attempted to put an early motor in a later Mogul chassis.
Thrust end float is not really an issue as the shaft is held in its mounting to limit shaft movement.
Thanks for explaining that correctly Tim.