Hello Fellow Hobbyists - I’m doing a DCC conversion on someone’s older LGB 20851 Two Motor Block Mallet which has a Phoenix Model 97 DC/DCC Sound Decoder previously installed. The person knew he striped the idler gear in the rear motor block during a railway crash, and when I removed the motor, the damaged idler gears were obvious. I’ve done the following: Installed a Massoth XL Power Decoder; installed Massoth DCC Pulsed Smoke Generator; Installed 2 new Idler Gears in each motor block (front motor block also showed some damage too); installed new LGB/Marklin E126050 motors in each motor block which required bending the motor’s electrical pins for proper motor block fitment (see photo); replaced two defective carbon brushes in front motor block.
Problem: The loco’s motor blocks run smooth when operating on my Piko DCC Central Station test stand or when tested with DC power. But when I test operate the loco on my indoor DCC layout powered by my Massoth Command Station/Massoth Power Supply, the loco doesn’t operate smoothly. There’s a slight amount of continual surging noticeable at Navigator speed setting 1, 2 , 3 etc. I took the bottom covers off both motor blocks and realigned the wheels/gears to ensure there’s properly meshing, no binding, and the loco still doesn’t run smoothly. I can’t figure out why this loco isn’t running smooth as silk like all my other locos. What diagnosis am I missing…advice please!