MTH Engine trouble

If the grease is not hard, I doubt it is causing the problem.  If they are older locos that weren't for a long period of time (new old stock), the armatures could be oxidized.  Running them will help or spraying the communtator through the access holes with non-flammable CRC contact cleaner usually helps motors run smoother and at a lower operating current.

Jon G posted:

If the grease is not hard, I doubt it is causing the problem.  If they are older locos that weren't for a long period of time (new old stock), the armatures could be oxidized.  Running them will help or spraying the communtator through the access holes with non-flammable CRC contact cleaner usually helps motors run smoother and at a lower operating current.

Spraying The Who what where? I thought mth motors were closed and aside from keeping the gears properly lubricated, there was no possible maintenance. Any chance you have a picture?

non-flammable CRC contact cleaner it is a spray aerosol can with usually a plastic tube you can attach to the top of the can and then can aim the nozzle where you need to spray .

https://www.bing.com/search?q=...405ebfb78f829400421d

you can buy this contact cleaner at any automotive parts center nappa auto , AutoZone ! wherever you buy automotive parts will work! it will clean up the oxidation on the brushes  and commutator inside the motor it is the end where the wire terminals come out! you don't want to pull the end off motor because if you don't know what you are doing you can break the brushes holder and then the motor is destroyed!

Alan

use the red can! in above web sight!

May I add, Make sure the CRC Cleaner is Plastic Compatible. I use CRC QD Electronic Cleaner. Item No. 05103. Says Plastic Safe on the front of the can. Have also used DE-Oxit 5 with good results. The CRC froze up a potentiometer after use one time on a guitar pot. This is when I started using De-oxit5. The new cans of De-oxit sprays a little too heavy in the new cans they are using. The old cans had a three way spray switch and was much more controllable.

Forest

Do you need to take the shell off the locomotive to gain access or is this access point on the underside? I know you tried to explain but I am still confused.

Do these motors even have brushes? I think we need more info before tearing into motors. Peter, do you have other engines running normally? How old are the engines, and what are their product numbers?

John H posted:

Do these motors even have brushes? I think we need more info before tearing into motors. Peter, do you have other engines running normally? How old are the engines, and what are their product numbers?

This was more to my question. MTH motors seem to be canisters with no real access points. 

The motor has access holes in the side of the can.  Aim the CRC up torwards the communtator/brushes, then run it.  The CRC cleans the commutator and removes the residue between the segments.  Yes, you do have to remove the shell.

Running under DCS or conventional? If conventional these locomotives have speed control, so they will run slower at most voltages to allow the speed control to have a power reserve to maintain constant speed. That can make the locomotive appear "sluggish" under conventional control. 

Before you do anything I suggest you get GRJ to comment or reach out to him directly. I am sure he will give you the correct answer and proper suggestions.

FWIW, I've repaired hundreds of can motor equipped locomotives.  It's actually very rare for the can motor brushes to need any maintenance, that's why they call them "maintenance free" motors.  I've personally never felt the need to "clean" any can motor brushes or commutators.  I've had a few can motors where they've just developed issues in the bronze bushings and get harder to rotate.  Occasionally, some oil will free them, but usually there's nothing frees them up and I replace them.  Can motor commutators are nothing like the flat commutator of a Pulmore motor, they're a different breed and really don't require the same kind of maintenance you have to do on a Pulmore AC motor.

Peter Frenzel 010119 posted:

I have  recently purchased both a Norfolk Southern and a Lehigh Valley mth premier heritage diesels. I noticed that they are running sluggish or barely at all. I noticed yellowish grease coming out the bottom of the rear trucks on both engines. Could this be the culprit if it’s gotten hard over time? What’s the best remedy to remove?

I seriously doubt the grease you see has anything to do with the can motor itself, it's almost surely the lube that was applied to the truck gear and motor worm.  In extreme cases, I take the trucks off totally, remove any painted parts like sideframes or pilots, and then hit them with carb cleaner.  Once I've totally removed the 20 year old grease, I proper lube them with Red-N-Tacky on the worm and internal gear, and my go-to lube, 5W-20W motor oil on all the axles and a drop on the external gears.  I use very little lube on external gears as that just invites them to pick up bits of ballast and jam the gears.

Cleaning motors with contact spray does work at improving performance.  Can come into play with the slave units especially.

I have also seen too much grease loaded into truck which runs up worm and through holes in can motor.  You can get it on the rotor.  Whether it makes it up to the commutator or not is another matter.

Most of the MTH grease I have seen does not get hard.  But you need to check for foam and other dirt getting in the grease and on the gears.  You also can get too much friction on motor if the gear box is over packed.  Smaller single motor engine effected more.  Hard to say what is going on with them with out an examination.  G