Lego 12V motor repair - metal end pieces

[trainrider]

Hi!

 

The  Lego 12V motor from my nephew 7740 started squeaking.

 

I noticed it squeaked in one direction but not the other.

In the noisy direction it was running slow and was getting warm, while in the other direction it ran pretty good. 

 

Disassembly.... With the help from the forum posts I got it open without much damage.

 

Some hairs, old grease.

But here is the question.

 

Those two round metal end pieces. one of them has almost a hole in the from the motor axle!

 

Questions:

Has anyone seen this?

Don't you think this explains the squeaking and low power in one direction?

It looks almost as if the motor axle has drilled a hole in the end piece.

How did this happen? Did the train got stuck somewhere and did it ran for hours? The copper pickups are still in pretty good shape.

 

How to fix this? I can rotate the metal end piece 180 degree so i'll have the good side facing the motor axle.

Still the is a little wear mark on the axle top. Can't fix that?

Polish paste?

 

Thanks for reading & helping!

 

 

 

 

 

 

 

 

Sorry for multi posting this earlier!

I just noticed i made two registrations. if an admin objects you may delete one of these two posts.

[trainrider]

Hi,

 

After just cleaning, and lubing with pfte and reversing the shim it startend sqeeking again.

So:

I sanded carefully the axle end with 2500 grit sandpaper.

Then I used polish paste. Both some leftover from car bumper repair.

I used a micosope on 50x to inpect it after each polish rond.

The amount of material taken of from the axle is minimal.

So far no sqeeking.

Pic below from the axle end.

I kinda wonder how this damage happend. Its copper contacts were in better shape then my childhoods train motor. I dont think it has ran that much (I was quite a fan as a kid - still are) Also the axle end and shim that was damaged was the forward direction.

 

 

Edited March 6 by trainrider