I have an Atlas HO GP-38 DCC , when going forward does not make any noise but running it in reverse or in consist it makes a squealing sound . I think I checked all that there is to check but still makes noise. Anyone have any suggestions?
That usually means too much fore and aft play in the drive train. When goign one direction, all the slop bunches up and puts pressure onthe motor from one side. When you reverse direction, it goes the other way. I'm not sure if those motors have thrust bearings, designed to take longitudenal forces on the motor shaft, but if it does, one is dry or defective. If not, it's just that the motor can handle it one way but not the other. THe solution there is to add thrust washes around the worms so they cannot shift back and forth so much. If they are needed between the work and drive shaft end, you'd have to pull the worms off. Adding washers to just the far end of the worm often is enough.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
You can add thrust washers without removing the worm gears as follows. Cut a 'V" groove in the washer with the bottom of the "V" just smaller than the shaft. The washer will then "snap" over ther shaft.