Hi everyone I just registered and looking forward to hearing from all of you. I have a problem with my Kato GP50. I believe the worm gears are stripping off the main gears on the trucks. I just put new truck assemblies on and they worked but the engine sounded bad kinda jerky, untill it stopped running altogether. The motor is running fine but it's not moving the model. Anyone experiance this also?
First off: Welcome to TrainBoard. You are going to like it here. To fix the problem it may be as simple as pulling the split frame apart and pulling the tabs from the motor out so they touch the frame. Now you get to put everything back together. Sometimes a fall or handling is just enough to bend those taps back in and they end up touching the side frames intermittently. The electric motor will turn slightly from side to side as you go from forward to reverse and sometimes this is just enough action to bend the tabs inward... toward the motor. Humm...you said the motor is running but the.....well....you'd do the above if the motor quit running. Better read on. Seems to me the comments that follow may help you. Now if the motor quits running...yep...back to the above. You may have reversed one of the trucks when you put the new ones on. You did put new ones on...right? If this doesn't work you might want to consider...naw...try this first.
Welcome to TrainBoard, AL N! These are a relatively simple mechanism. It sounds like binding - have you any model oil and grease on hand? First I would separate the trucks from the chassis and try running the motor with the drive shafts attached. I haven't heard of it but the support bearings on the end of the worm drive may be dry. Whilst at it, give the motor bearings a spot of oil as well - don't overdo it! Next, try pushing the trucks by hand (or turning the gearing) to see if there is any binding in them. Since they are new I wouldn't expect so. Also try the old trucks as well. Let us know what you find.
Mine is experiancing simaler problems, the moter is running but the engine is not moving, or when it does it is very jerky. The problem is the joint at the end of the moter shafts is coming loose, and moving back and forth on the shaft. I have not fixed mine yet but I was thinking mabey some small washers could be used as spacers and a dab of CA would hold the joint in place. Kevin
It is the piece that is attached to the motor shaft. They tend to come loose whether from use or just old age and the plastic getting brittle. I have successfully in several engines removed the piece put a drop of CA and re-attach and make sure it is in the same spot as when you removed it or you will cause a binding with the cross and worm gear. The engines I have done this fix on have never had anymore problems after that.
This won't help fix the Kato mechanism, but if all else fails, you can cut out the motor mount tabs and inner bracing from the sill/walkway so that the complete shell assembly fits over an Atlas GP38/40 mech. I used an X-acto #13 saw blade. Be sure to use Atlas Dash-2 sideframes with snubbers. It's great for those looking for a drop-in DCC option and also updates it to a mech that's easier to maintain. I then kept the old mech and motor for spare parts on my other GP50s. Walthers/LL GP38-2s are around $30 and would probably work too. Oh, and by buying spare sideframes and a new fuel tank for a buck or two from Atlas, I was able to preserve the entire factory painted shell of the original donor GP40-2, just in case I wanted to change it back.
OK sorry it took so long, been busy with my layout and a Con-cor F3A which is now running. So I took the GP50 body off and put the frame on my test track. The motor and the two brass flywheels both are turning perfectly. Then I took it apart and checked the joints on the shafts, they are tight. But guess what I found, both double gears are stripped. Maby I had the trucks reversed? So I am thinking "just get the double gears" but, Kato is sold out on this part (Pt 07-0335). Anyone got any ideas? I really want to get this running again, it was sweet.
If you buy new trucks from Kato (they are available), you can get the gears. Might be worth the money to you if you can't get them elsewhere.
Got the gears and carefully cleaned and assembled this engine back together. Put it on my test track without the body to watch the flywheels and gears as they turned and glory be it ran so smooth. I tried to calm myself thinking take it easy so I put it on the layout and ran it slow for awhile. Then a little grease with a toothpic and the body back on. It's alive! after years in a box and thanks to a stranger in Texas It's on track. Thanks Russel and everyone else for your time and comments. This site rock's and so does my GP50 again.
I've set it before and I'll say it again- TrainBoard is the best model railroading community on the planet. Jamie
Seams to me that the worm has striped its mate. But not completley, in other words, its out of mesh just by a touch.. Good luck on getting it fixed
On a kind of related note, there have been many Kato GP50s turning up on a certain auction site in the last few weeks. A couple of other forums have posted unconfirmed rumors that Kato is going to announce a new run very soon. (How long since they last produced these?) It would be nice if this is true.
