Screaming Life-Like E7 loco

[dougnelson]

I have a Life-Like EMD E7 that works fine except that the mechanism starts a loud SCREAM after accelerating.  I have added grease lube to the gears and that may have helped, but the screaming is back.  It mainly happens at higher speeds and seems triggered by fast acceleration.  Works fine at low speeds. Any thoughts to solve this problem?  More grease?
Thanks!

[C855B]

Not the gears. Light oil (and a very, very small amount!) on motor bearings and bearing blocks each side of the worms.

[dougnelson]

That worked!  Thanks Mike.

[C855B]

You're most certainly welcome, Doug!

[randgust]

Also known as the Kato screech.

What's amazing is that with a good sintered bearing, one very light application can cure it for over a year.

But if you overdo it, and it gets in the commutator, and starts developing carbon deposits from arcing, you'll be cleaning that motor armature for the rest of your life.

[Doug G.]

What happens is, without enough lubrication, the motor shaft, instead of just rotating within the bushing, travels around the inner surface of the bushing because of friction and the play (space) between the shaft and bushing surface, thus causing the squealing from the vibration.

Doug