Kato P42 (Amtrak)

[carmelmodelrr]

I am running (DC) a pair of the first Kato Amtrak P42's which WERE still running well until the last few days.  Now they will be pulling their consist as usual when suddenly, after about 30 minutes of running, there will be a loud crack coming from one of the locos.  After that, the speed declines considerably until I give up, disassemble them, re-assemble them and then things are OK for awhile--until there is another crack.  Although I've dis- and re-assembled them several times I cannot determine what causes the crack--or even which loco is doing it. 

Thank you for any suggestions.

carmelmodelrr

[eja]

I would start by running them individually 

[carmelmodelrr]

The more I think about this the more I wonder if it is the Kato lo-pro wheels derailing on Atlas code 80 track which has 11” curves.  I’m not able to check on this until tomorrow.

Carmelmodelrr

[nscaler711]

Ok, I've had a similar issue in the past with one before.
Check the green piece (universal) on the drive linkage, see if its cracked anywhere, if so, replace it with a new one.  Kato # 926580
http://search.cartserver.com/search/search.cgi?cartid=s-1078&keywords=NP42&maxhits=100&go=List+Parts&bool=AND&bool=AND

Alternatively, check to make sure there is absolutely nothing in the gears, and look for damaged gears while your at it, granted its uncommon that Kato gears just crack or break. I've got one with hundreds of hours on it, and honestly the only things I've had to replace is the DC board due to LEDs burning out, and guess what else, the drive shafts. For reference its AMTK P42 #134 (106-6103,) this locomotive is every bit of 19 years old.

As far as derailing on C80 with low pro wheels, not a chance. these babys can do 9 3/4" curves but they don't like it. and will rip everything off the track with short couplers.
Bought that one when I was a teen, I ran Bachmann EZ track and it was the only one that never gave me issues.

[carmelmodelrr]

I finally received the worm gear and joint set from Kato and installed them.  The locos run “like new”.  Thank you for the suggestion.

Carmelmodelrr

[oakcreekco]

Ok, I've had a similar issue in the past with one before.
Check the green piece (universal) on the drive linkage, see if its cracked anywhere, if so, replace it with a new one.  Kato # 926580
http://search.cartserver.com/search/search.cgi?cartid=s-1078&keywords=NP42&maxhits=100&go=List+Parts&bool=AND&bool=AND

Alternatively, check to make sure there is absolutely nothing in the gears, and look for damaged gears while your at it, granted its uncommon that Kato gears just crack or break. I've got one with hundreds of hours on it, and honestly the only things I've had to replace is the DC board due to LEDs burning out, and guess what else, the drive shafts. For reference its AMTK P42 #134 (106-6103,) this locomotive is every bit of 19 years old.

As far as derailing on C80 with low pro wheels, not a chance. these babys can do 9 3/4" curves but they don't like it. and will rip everything off the track with short couplers.
Bought that one when I was a teen, I ran Bachmann EZ track and it was the only one that never gave me issues.

Thanks for the "heads up" on this. I've got a pair in the Ski Train paint, and it's been a while since they've been on the rails.

Need to check this out.