Motor drag williams rdc

It only takes a small amount of grit in the spur gears to cause this. If you want to check further, remove the shell, hold on to the motor and remove the phillips screw under the truck.

Pete

Hi, I would suggest you clean OUT THE GEAR box and flush it with a good solvent then automotive spray cleaner and then blow dry with compressor, then install thick and tackey grease then I'll bet your engine will then purr!

sounds like you might have dirt or Debree in the gear mechanism thoroughly wash that out as well.

Alan

@Alan Mancus posted:

Hi, I would suggest you clean OUT THE GEAR box and flush it with a good solvent then automotive spray cleaner and then blow dry with compressor, then install thick and tackey grease then I'll bet your engine will then purr!

sounds like you might have dirt or Debree in the gear mechanism thoroughly wash that out as well.

Alan

Good diagnosis,  opened it up, loaded with gunk.  Hand cleaned as much as i could, need to get a solvent, thanks for the tip.

Check closely for a split gear.  Although it's not as common as plastic gears splitting, I've run across a number of brass (bronze) gears that have split.  It will present as a slight catch in the rotation.

If the bind happens every flywheel rotation its in the gearbox but if it happens every wheel rotation its in the spur gears. Yes some Williams diesels did get grease that turns to epoxy over time. It can get so bad it will stall the motor.

These only have a single powered truck so removing the truck and cleaning everything is a good idea and not difficult.

Pete

@Norton posted:

If the bind happens every flywheel rotation its in the gearbox but if it happens every wheel rotation its in the spur gears. Yes some Williams diesels did get grease that turns to epoxy over time. It can get so bad it will stall the motor.

These only have a single powered truck so removing the truck and cleaning everything is a good idea and not difficult.

Pete

Happens with every flywheel rotation.  It is dual motored so if i cannot get it working properly I'll just pull the motor.  One thing i did notice that might be the issue is the brass gear on the axle that engages with the worm gear from the motor floats ftom side to side on the axle.   If that play is normal so be it.  I suspect this play may well be the cause of the problem.  Since I'm cleaning up one motor the other if probably in the same condition.  Once I open up and clean that one I'll be able to see if this float is normal.

Sounds like maybe John’s suggestion of cracked worm gear might be case here. It shouldn't move side to side and if cracked would no longer be tight on the shaft. I doubt Williams has parts but the gear might be able to soldered together and then pinned or epoxied to the shaft.

Pete

That gear should be solidly fixed to the axle, it shouldn't be moving around.  One problem with a split gear is even if you get it attached to the shaft it might still have a "bump" as it goes by the split.

@Norton posted:

Sounds like maybe John’s suggestion of cracked worm gear might be case here. It shouldn't move side to side and if cracked would no longer be tight on the shaft. I doubt Williams has parts but the gear might be able to soldered together and then pinned or epoxied to the shaft.

Pete

The worm gear is fine, no movement other than what it should be doing.  The first gear it engages on the axle slides from side to side.  John i think has described the problem.  The solution for now is pull the motor and run the rdc as a single motor unit.  I may just swap out a truck from one of the dummy units so i can play with the problem truck in a more controlled environment.

Just to make sure we have the same terminology. The worm gear is on the shaft that runs across the truck to the spur gears typically bronze. The gear on the motor is called the worm, usually steel.

Pete

Frank Timko at Timko's Repair Depot has replaced many of the brass gears for us.  We usually just send him the truck.

@Norton posted:

Just to make sure we have the same terminology. The worm gear is on the shaft that runs across the truck to the spur gears typically bronze. The gear on the motor is called the worm, usually steel.

Pete

You are correct, I'm not up to date on the correct terminology.  The spur gear is the one that is moving side to side and I think is the cause of the binding.

@Mountain Mover posted:

Frank Timko at Timko's Repair Depot has replaced many of the brass gears for us.  We usually just send him the truck.

Thanks, probably my best option.

To close this out, offending truck removed and replaced with a dummy truck from another rdc.  Unit runs just fine with err cruise control and one motor.  Once the problem child is repaired I'll have two powered units, win win.