i have two kato n scale locos they both have mrc decoders. The lead loco has sound the other does not. Both are the same loco (SD70mac) the problem im having is the speed and accelaration matching every time i seem to get it close and operate it for a session and put it away the next time i go to use it they seem off by a considerable amount. Mainly i dont know how to use start voltage cv's and im not sure if that is my problem or not. Basicly what happens is the lead loco will start moving earlier than the other and it also accelerates much faster resulting in dragging the second loco. even after offsetting the cv settings considerably to make up for the lagging loco didn't make much of a difference.
Step 1 .Time to learn about speed matching! There have been many threads already on this topic so far so just do a search first and see if previous items will help. If not we will be back later.
Step 2 .Also on another note check the grease level in the gears of both and clean them and pt minimal grease back or a proper oil. If the locos run alot the grease melts to a certain degree but the next morning the grease has cooled and harded again causing a difference in loco speed.
it will help if both loco's are run in, also match the speeds first without any accelleration or decelleration to confuse things. does having the sound on or off affect the speed at all??