Thrust Washers on many but not all vertical PW AC motors?

[pgtr]

When I took my badly sparking 1963-4 221 ALCO vertical motor apart to clean it I noticed it had no bushings or thrust washers on either the top or bottom portion. Looking in my Greenberg's Repair Manual (GRM) the closest I could find was the '200 series' section that has a post 1958 variation shown but does not explicitly include the 221. The GRM shows a thrust washer (600-129) and washer (CON-8) on the upper shaft beneath the brush plate. And it shows nothing on the lower shaft.

Thumbing through the GRM I find many vertical shaft motors have 1 or 2 thrust washers (671M-23) and a thrust bearing (681-121) on the BOTTOM of the motor where the shaft extends down to the axle(s).

Depending up on the direction the motor operates in based on the direction of the loco - the armature I believe will run against either the brush plate or the motor housing...


Q: Why don't some vertical motors such as the one in my 63-4 221 ALCO show thrust bushings or washers on the lower portion as well?


Q: Since I need to order replacements for the upper - would it be prudent to put something on the lower shaft as well? There is I'd guestimate a 1/16" or so of end play on the shaft currently (remember nothing is currently installed on the motor at either end). If so any specific part# suggestions?