I was finally able to answer my own question.  The ashpan underneath the shay is not that difficult to remove and it then reveals a motor bearing and several gears.  After lubing all these parts the locomotive ran much quieter.
The following link was a big help in removing the necessary parts:

http://www.all-model-railroading.co.uk/forum/showthread.php?p=61179

Good Afternoon Folks,

Hoping someone can help with what I thought was going to be an easy procedure.  My HO Spectrum 3 Trk Shay, purchased around 1999-2000, was making a loud noise best described as "screetching." I was able to easily apply a light amount of plastic compatible oil on the wheel bearings, beveled gears, and external crankshaft but the noise continued and seems to be coming from the worm gear/motor inside the boiler.   Can't seem to find a way to lubricate the motor bearings or worm gear mechanism.  Does one have to remove the boiler or is there an easier way?  And how would the boiler be removed, it looks like a rather difficult operation and not one I'm looking forward to?
Wayne

Guys,
Thanks for all your help, it is appreciated.  The Shay has been returned but I will keep all your excellent ideas in mind if this ever happens again. 
Wayne

Quote from: kevin2083 on March 05, 2008, 04:29:46 PM
First, check to make sure the little orange plugs between the water tank and coal(or oil) bunker are in all the way. Then check the dcc shorting plug in the water tank if that doesn't work. The dcc plug thing is unlikely, but still worth a try (BTW, make sure to carefully take off the rear ladder before removing the water tank)

Does the firebox light come on too?
Any wierd noises it made before it quit?

I hope you get it working soon, it's a fun little loco. looks great too.

Kevin,
Thanks for the help, I did check the orange plugs in the water tank and they seemed fine but cannot remember if the firebox light came on or not.  Unfortunately, the locomotive has been sent back so I'm not able to check anything else.  However, there were no noises at all coming from the engine, or electrical motor. 
Wayne

Having an unusal problem and hoping someone may have an idea of what may be wrong.  I recently ordered a Bachmann HO Scale 3 Trk Shay (DC) that ran perfectly for one day.  The following day it would not run at all; however, the front and rear lights operated and changed intensity with various throttle settings.  The on-line supplier was very cooperative and immediately sent me a replacement.  But then I had the identical problem with the second Shay.  Only this time the replacement Shay ran perfectly for 3-4 hours and then just quit.  And just as before, the lights on the Shay would operate, but the locomotive would not move.

All of my other locomotives run perfectly well, my Power Pack is a Railpower 1300, and I do not run DCC at all.  I just don't know if the problem is with my particular setup or did I just run into a bad batch of locos from Bachmann?  Any ideas would be appreciated as I would really love to add this Shay to my layout.   

Wayne