How to fix motor brush contact issue

[abu0724]

I just bought a NEW SD40-2 from a reputable ebay retailer. it seems the motor have issue to start spinning due to a poor contact with the brush at a specific location. if I spin the motor manually, it will start running no problem. If it stopped at that location, it will have issue to start again. other locations seems to be fine. I thought this is an issue without breaking in. So I let it run for about 1 hour with variable speeds and frequent starts/stops (all manual work). this only gives little-to-no improvement. What would be my next step to resolve this problem? conductive lubrication to the brush? If I need to open the motor, what would be the proper way opening it without damage? mailing it back for repair/replacement is not going to be cost effective. but if there is no other ways to repair it myself, does anyone know how long it is going to take? which I will mail a GP35 back for repair as well. (Super noisy engine, I own more than 10 Bachmann engines, so, i know what noisy means, but this one is super noisy even after break-in. this GP35 also had similar problem with motor starting, but the problem went away after break-in.) with 40% of my bachmann engines having problems right out of the box (I purchases 5 in the last 2 months), I dont know whether I am going to purchase another Bachmann or not.

[JerryB]

Since this is a new unit, I would strongly recommend sending it back to the seller. As a retailer, they have a duty to provide a working unit, so they might also cover the cost of the return shipping if asked nicely.

As to putting "conductive" lubricants on the armature, that is liable to make it not work at all.

Trying to take the motor apart will most likely result in destroying it. They are not designed to be 'serviced.'

Also, once you have 'worked on' a new unit, it becomes more difficult to get the lifetime warranty honored.

[bobwrgt]

Break it in, in FWR and REV.
If this does not help contact Bachmann Service and ask for a replacement motor under Warranty. They have sent me some in the past. Just be nice.
When you have the replacement motor you can try to clean the brushes on the old one. You have to remove the brass plate that holds in the brush and spring. It slides out.  The spring sometimes gets lost. It's hard to hold down in the hole while you slide the plate back in.

Bob

[NarrowMinded]

What do you mean by it stops in the same spot? have you marked the gear and see where is stops?

Check to make sure the gears have nothing lodged in them.

if all else fails and it's too costly see if you can get a replacement motor sent to you.

NM.Jeff