I finally got around to installing an ESU Nano in my Southern Pacific MP15DC. Now I'm getting a good amount of grinding and hesitation. I must have unassembled and resembled the unit half a dozen times. Does anyone know if the truck directions make a difference? Also when I was cleaning the engine I noticed one of the flywheels had 3 small pieces of metal in its end lip. Near where the worm gear would attach. (It's usually a blue colored putty). I thought it was debris and removed it not knowing if it was related to balance the engine / flywheel. Not sure if anyone has ever seen this. I tried cleaning and lubing as necessary with labelles grease and oil. I also read somewhere that the screws that keep the metal halves together shouldn't be over tightened and can help prevent binding during operation. Also not sure if the round white teflon pieces that sit between the worm gear and the bearing block need to be in a certain condition. Any thoughts or recommendation?
On my phone so reply will be brief. Did you make sure the orientation of the bearing blocks are the same as when you originally disassembled it? They are not as square as they may appear and they all need to be the same.
Grinding is a pretty good sign something is not lined up properly......if it's grinding there would be a lot of drag in the drivetrain, which would cause the hesitation. As far as the direction of the trucks, it can make a difference on some models, but as a rule, you'll know right away if it's "wrong" because the truck will hit the fuel tank or other things...........and if the truck tower fits into the chassis, that shouldn't cause your issues. Did you dissemble the trucks? All the gears are held in place by pins, and if one of them fell out, the gear could shift and produce the grinding/binding. And as tehachapifan mentioned, if the bearing blocks are not seated in the chassis properly, it can cause issues as well. The now unbalanced flywheel shouldn't cause the grinding or hesitation, but the loco may be a bit noisier (vibration noise) .
It appears the chassis halves were not completely squeezed close enough, so there was a small gap due to when I had to shove a snipped old board to solder to for connections to the chassis. Seems to be working quite a bit smoother, although I feel when I go through the process of cleaning, regreasing and re-lubing sometimes a diesel will be louder. Talk about being finicky.
