Atlas SD50 U-joint

[Chris1274]

I agree with Tim on the Kato wheel replacement. Looks much better and I like how it performs. Tim actually typed up a nice description of the process in an email to me about two years ago (thanks!). Since then, I've upgraded at least a dozen units (Atlas SD50 / SD60 and Intermountain SD40T-2, SD45T-2 and SD45-2). All look way better and it cost just a bit more per axle as upgrading a freight car to metal wheels.

Glad you got it quieted down!

Indeed, it's a great suggestion. It looks like they come in sets of 4 axles, so I'm going to order three sets and change out the wheels on both of my SD50s.

What Kato wheelsets did you use, with gears?  I agree - they do look much better.

Tim gave the part number as 932090.

[mmagliaro]

I tried Tim Benson's suggestion and here's the result:

I couldn't pull the ball joint any further outward than that, but I still think it's an improvement. The universal now extends into the flywheel about the same amount as the other one does.
I think that's an optical illusion. I double checked and they're all installed in the same way. I also tried rotating them 90 degrees but they wouldn't fit that way.
It can't be done by hand, at any rate. I just tried on a spare motor and the flywheel wouldn't budge.

Regarding moving the flywheel on the motor shaft... NO you cannot do this by hand and should not even try.
Just pulling and tugging on it is a very bad idea, and if you are unlucky, you might pull the shaft through the armature and destroy the motor.  If you do decide to do this, you have to use a wheel puller (NWSL "The Puller" will work).
But it seems like you've got it running well in any event.

[Chris1274]

The Atlas SD50/SD60 mechanism suffers from a lot of issues and can be hard to get working smoothly. I've had good experience swapping out the Atlas wheel sets and replacing them with Kato 932090 wheels. The Kato wheels have longer points on the ends of the axles, and this reduces the floating axle problem that the Atlas HT-C trucks suffer from. They also look a lot nicer…

A quick follow up: I just replaced the original Atlas wheels with Kato 932090 wheels and the improvement in the locomotive's performance is remarkable. Thanks again for the suggestion!