Issue with Kato NW2 Switcher

[chuck geiger]

Yesterday I took the loco to clean the trucks/wheels with alcohol, Put some on a Q-Tip and cleaned the wheels, then took a piece of
cloth with alcohol on it and sat the front trucks on it (on powered track)  and spun for a second and stopped. Loco went dead. Heard the motor running but
no power to the trucks. Took it apart and nothing seemed weird, contact rails were a pain to get back in. Tried again and the lights are on
and the motor runs but no power to the trucks. This is an older unit bought used two years ago and it's DC. Any idea what's up here?
Hard to find diagrams and information on these units. Saw that on a search here as well.

[kornellred]

These models are known (unfortunately) for sometimes having a drive gear slippage (press-fit gear loosening up on the drive shaft).  If the gear is not cracked, it is possible to use some super glue to ameliorate the situation.  The drive on the NW2 is somewhat unusual in configuration.

[brokemoto]

There have been several complaints about various plastic parts in the drive train that crack.  There have been similar complaints bout the RDCs..  Some have managed to use Super Glue in the cracks and it has worked.  I only had one RDC ever show this; I have several of the RDCs.  I have two of the NW-2s.  Neither has shown this problem Y-E-T.

[Chris333]

http://www.spookshow.net/loco/katonw2.html

[chuck geiger]

Chris333 thanks for the info. I have spent weeks tinkering with this and can't get the motor to run now, the lights come on. before today the motor was running but no movement from the unit.

[chuck geiger]

Thanks to Ben Horne who took the engine and repaired it and is sending it back @GM50 4164 What a great Railwire member.

[peteski]

Thanks to Ben Horne who took the engine and repaired it and is sending it back @GM50 4164 What a great Railwire member.

That's great, but it would also be nice to know what the fix was.

[GM50 4164]

That's great, but it would also be nice to know what the fix was.

When I got the NW2 case in the mail, I discovered several pieces loose. One happened to be shaft that goes between the worm gear on the truck and the crank case at the motor. That was a easy re-install. Unfortunately there was no other in the case. I ordered another truck with the shaft from the Kato store and re-installed it the other day. Having only the one allowed the locomotive to move but it was dragging the rear truck.

[peteski]

So it wasn't the typical gear slippage issue common in these locos. Thanks Benjamin!

[GM50 4164]

No not in this case. I coupled up some cars to it and hauled them around on my loop and it pulled them just fine.

[chuck geiger]

I learned a lot about this with this process. I had no idea those small gear pins were missing, one in the jewel case and one missing on the layout after the mishap described above. I had everything put back together and couldn't figure out how the gears were supposed to drive between the trucks and the tube that runs through the gear shaft. Silly me.

[GM50 4164]

I learned a lot about this with this process. I had no idea those small gear pins were missing, one in the jewel case and one missing on the layout after the mishap described above. I had everything put back together and couldn't figure out how the gears were supposed to drive between the trucks and the tube that runs through the gear shaft. Silly me.

Not everyone is comfortable disassembling these things Chuck, no need to sweat about it. These things happen and that's why we are a great community of modelers, we help each other out. It should arrive on the railroad's property by Friday ready to earn its keep!

[chuck geiger]

Thanks Ben

[peteski]

Just for reference, I have a photo (the dark gray truck) that shows the universal coupling and short driveshaft.  The end of that driveshaft plugs into the universal coupling which is in the motor assembly.





The silver truck (of similar construction)  is for Kato RDC and the driveshaft is not shown (just the universal coupling).

[randgust]

FYI that's the same driveshaft used in the Kato 11-105 'critter' chassis, which is inexpensive enough to become a parts donor in an emergency

I've got two Kato NW2's; one repowered a Life-Like SW shell (much more reliable electrical pickup) and a spare for future parts.   I always wanted to use that  revolutionary 'drop transmission' for some other projects but Kato doesn't sell those separately.

My biggest complaint about the LL drive is that the wheels oxidized up so much it required wheel cleaning every time I wanted to use it, which usually meant dragging it out of the enginehouse by hand and cleaning the wheels.   The Kato drive does not have that problem at all and has slightly better tractive effort.   I know LL (Walthers) has it's defenders, but that's my experience.