Kato SD45 squealing at midrange throttle

[Tom4884]

I have a Kato SD45 that has developed quite a squeal between 20 and 80% throttle setting.  At lower power it's quite as a mouse, and at full power just the normal whine of the motor.  I have taken it completely apart,  cleaned the drive train, lightly oiled the bearing blocks and applied a dab of Labelle grease to the worm gears.  After all of that it actually seems worse!  At a loss of where to go next, any advice greatly appreciated.

Thanks,  Tom

[oakcreekco]

Sounds like the motor bearings are dry.

Put one very small drop of the Labelle oil on the shaft, next to the motor bearing. Rotate the motor slowly by hand to help the oil migrate into the bearing area.

Best of luck.

[Sokramiketes]

OakCreekCo has it, this is the trademark sound of dry motor bearings. 

[peteski]

Or the worm bearings, since they all rotate at the same (squeal-producing) speed.  If the model is apart, makes sense to oil them all.

[C855B]

... If the model is apart, makes sense to oil them all.

Lightly! Lightly! Tiny drop at each bearing! Wow.

(He already said he did the bearing blocks, BTW.)

[peteski]

Lightly! Lightly! Tiny drop at each bearing! Wow.

Well, I thought that since all the maintenance instructions (when) included with the models for the last 50 years always state "oil lightly", I thought it was implied.  But yes, that is sound advice.

[tehachapifan]

Lightly! Lightly! Tiny drop at each bearing! Wow.

(He already said he did the bearing blocks, BTW.)

A good way to control the amount is by putting a tiny drop on the end of, say, an .008 or .010" wire and apply that to the bearing. Highly caution against applying straight from bottle. Too much can seriously affect the motor.

[Sokramiketes]

Or the worm bearings, since they all rotate at the same (squeal-producing) speed.  If the model is apart, makes sense to oil them all.

Same speed, but different sound.  At least in my experience.  The plastic bushing housings don't seem to get the same screechiness.  Is that a word? Howl?

[mmagliaro]

Did you happen to run the motor by itself while you had it all apart?  Did it screech then?

[Tom4884]

Sounds like the motor bearings are dry.

Put one very small drop of the Labelle oil on the shaft, next to the motor bearing. Rotate the motor slowly by hand to help the oil migrate into the bearing area.

Best of luck.

Thanks, that did the trick.  I bought this one second hand and no idea how much run time it had, was thinking of checking the motor brushes on its next visit to the workbench. 

Tom

[oakcreekco]

Good deal and you're welcome.