Need help finding motor for MTH Southern FM (item # 30-2805-1) OLD title-Worm gear slipping on MTH motor shaft problem

Putting a bit of blue thread locker on the shaft should fix the issue

Boy that is a new one.  Never saw that before.  If you can pull off by hand I don't think loctite would be a permanent fix.  I would look to see if the worm is actually cracked.  You could order a new motor.  G

I’d agree with George (GGG) on this one, ….usually those gears are pressed on those motors with the same force that turns coal into diamonds,….I’ve seen those gears develop cracks,…with the advent of the new MTH parts company (mthpartsandsales.com) you can simply buy a new whole motor assembly as a bolt in job…..

Pat

@GGG posted:

Boy that is a new one.  Never saw that before.  If you can pull off by hand I don't think loctite would be a permanent fix.  I would look to see if the worm is actually cracked.  You could order a new motor.  G

We have seen that at MTH.  Quite rare, but the symptom is the flywheel spinning with the gear slipping on the shaft.  The worm has a stepped hole, so only the part near the motor is fixed to the shaft.

@MichaelB posted:

Putting a bit of blue thread locker on the shaft should fix the issue

I've never seen that happen, but if you want to try to fix this one, I'd use Loctite 680 retaining compound.  As others have said, it almost sounds like the worm is cracked, they're normally on there with a vengeance!

It is usually the opposite.  As Jim G said, the press is at the bottom of the worm gear and they are extremely hard to get off.  Blue loctite will not hold it.  If you don't have another worm gear, I would take George's advice and order a new motor.

@David Minarik posted:

As Jim G said, the press is at the bottom of the worm gear and they are extremely hard to get off.

I can attest to that, I bent the pin on my gear puller trying to get one off!  I'm going to go back to the well with a harder pin and more heat the next time.

Thanks to all who replied!  The worm just slips right off and there are no signs that he shaft was ever staked.

I was just able to find the MTH product number  (30-2805-1) so that I could order the motor.  Unfortunately, the MTH parts side says mechanical parts "List coming soon".

I suspect the motor is used many other models so I was wondering if anyone knew the correct part number for motor with tack and sensor installed,

I appreciate the help,

Don

Contact MTH parts via e-mail. Most items aren't on the web-site yet. I was able to get parts that weren't listed by getting in contact with them.

If it were mine I'd use Loctite 680 on it and see if it would hold. For less than $25 it might do the job. If it didn't hold then I'd replace the assembly. But then I prefer trying the simplest least expensive solution first.

I'd second the idea of using Loctite 680 on it, that's my go-to solution for loose wheels, gears and flywheels.

Take other motor out and measure the diameter, length and length of thread section of the worm gear.  Also Fly Wheel diameter and height.  All in metric mm.

I can see if I can provide the match.  G

My day's not wasted...learned something new from the Forum again!

Never knew about Loctite680....pretty neat stuff.

You guys are the best!

Don.
I would suggest using the Railking Diesel motor chart to locate the motor you are looking for.

Thank you,
Mike
MTH Parts & Sales LLC

Shaft Loctite is the cure, if the worm is not split.  I fixed a pulley on a small table saw that way 40 years ago, and it is still holding.  We do driver tires, and even loose driver axles with shaft Loctite.

The proper nomenclature - the thing on the motor shaft is the "worm" and the gear on the axle is the "worm gear."

I have a pair of brand new MTH SD trucks with motors - but I am going to sell them as a pair.