KATO FEF Struggling...

[moehrc]

Hello all... I am currently experiencing some major struggling issues my KATO UP FEF is having. Right now, as I put it into full throttle, the engine barley moves at all, but the motor still continues to whir up a storm. My dad has checked the worm gear, and saw nothing wrong with it, and managed to knock out some of the excess oil. But it still continues to be fussy... any help? Could it be the motor?

[Albert in N]

Sounds like the same problem I have with a Kato mikado.  I replaced the universal joints with new Kato parts and checked out gears and seemed OK and nothing loose. Then I put it back together and same motor whirring but little motion, either forward or reverse.  I have never had a problem like that with my many Kato diesels.  Hope you find someone with a solution.

[peteski]

Here is a diagram of the drive train.  If you can hear the motor running while the loco is struggling to run then the motor is most likely good. From all the parts shown on the diagram the most likely causes of the problem are indicated by the red and green arrows.

The red arrow is pointing out the motor half of the universal coupling. It is press fit on the motor shaft.  If the motor shaft is slipping in that coupling, that woudl result in the problem you describe.  In the past I have seen those couplings split (cracked) which means that they loosely fit over the shaft. but I have not yet seen that on this specific model.  If that is the culprit then unfortunately you have to replace the entire motor (since Kato does not sell that coupling as a separate part).  But you might want to contact Kato (call them) and maybe they will send a new coupling to you - their service department is very accommodating.

The other possibility I see is that the worm bearings retainer (green arrow) is not fully seated in the chassis. That will allow the worm bearings to move up and the worm will not fully be engaged with the worm gear below it. That could cause the worm to spin without turning the worm gear (so the loco will not be moving very well).

Another alternative is to sent the model to Kato for repair.

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[fredmoehrle]

Peteski,
I can not move the Worm bearing retainer, tried for about an hour last night.
At least not without loosening the frame halves.
I can have my son contact Kato about the coupling, does the diagram expand to show the part #?
That would be really useful.
Thanks for the help.
Fred Moehrle

[peteski]

So you suspect that the worm is not engaging properly with the worm gear?

Did you verify that the universal coupling is not the problem?

I found the exploded diagram from which I snipped the above picture right on Kato USA website.
On thebu main page, under the N scale button on the top I selected N Scale North American Locomotives.
Then clicked on FEF3, then Maintenence, then on
Downloadable (3MB) Exploded view diagram for the N scale FEF-3
You can get the part # if you go to the Kato's parts shop (link on the bottom of the main page) then in the parts store just search for FEF. That will bring the parts listings including the part you are looking for.

The other question I have is how did the problem develop?  Did it just happen suddenly with no changes made to the model, or was some sort of work done on the mechanism prior to then the problem showed up?  Or was the loco dropped or some similar thing happened?

[peteski]

I just too my model apart. If the worm bearing retainer was not seated properly then the circuit board above it would not fit into the chassis.  The retainer has tabs on the sides which fit into slots in the chassis. I just used a hobby knife inserted between the retainer and the side of the chassis and it popped right out and flew down to the floor.  But if the retainer is in the chassis and the circuit board fits over it properly then that is not the problem area.

I would pop out the motor and the universal joint (they all come out as a single assembly) and check how loose the U-joint piece is on the motor shaft.

[mmagliaro]

Have you tried running it with the shell off?  The flywheel/worm shaft is clearly visible around the edges of the circuit board once the shell is off.  If you can see the flywheels and worm whizzing around, then the motor U-joint coupling is not the problem.  But that coupling is where my money is.  I bet you will see the flywheels spinning slowly and intermittently, even though you hear the motor turning at full speed. That surely points to the coupling on that motor shaft.