I accidentally murdered my Model Power 4-6-2

[Loren Perry]

I have a Model Power die cast 4-6-2 Pacific that I've cosmetically modified into a close representation of a Southern Pacific locomotive (Engine No. 2477) and it's always had an annoying buzzing sound that I traced to the worm and motor shaft. It buzzes even when the drivers and running gear are completely disengaged. Because of the way MP built the motor and worm into the die cast metal boiler, I've never been able to figure out how to gain access to it, so I just lived with it.

So now, while trying to clean the drivers and solve an intermittent electrical pickup problem, I removed the bottom plate to clean out lint and dust. When I reassembled it, the drivers' gearing would no longer fully engage and now the worm seems to be skipping over the teeth of the large spur gear beneath it. I can't for the life of me figure out how to access the worm or adjust its position. I've been working under magnification (Opti-Visors) and good lighting and have somehow missed something when it comes to getting the correct mesh. But the infernal design of the Model Power die-cast 4-6-2 makes troubleshooting and adjusting nearly impossible, at least for me. For now, the loco has been put on the dead line in my engine terminal and another steamer has taken over its duties.

Anyone out there with experience in taking a MP 4-6-2 apart and successfully getting it back into running condition?

[superturbine]

As a matter of fact!   One screw under the driver box plate and one at the pilot secure the boiler and ensure proper mesh.....Make sure your motor has not pushed slightly back.  You have a back head that snaps into place and secures the motor.  You will have to remove the cab

[superturbine]

The worm screw is direcly attached to the motor shaft.  So either the boiler is slightly loose or the motor had slightly moved in the mounted position

[Chris333]

Yeah the motor just slides out the rear of the boiler and is a snug fit. All the wires are what makes it a real pain.

[Chris333]

Also under the fire box there are 2 slots for wires. If you don't have the wires in the slots the boiler might not sit all the way down.

Just ideas.

[Loren Perry]

Thanks for the tips, guys! (And thanks, Jason - it's terrific to have you back!)

I'll see if I can get the backhead and cab off without wrecking everything and will go from there.

[Point353]

See if the information in the following links is of any help:
http://www.nscale.net/forums/showthread.php?17582-Model-Power-4-6-2-Disassembly
http://www.trainweb.org/nrmrc/dccconv/mp462.pdf

[Cajonpassfan]

Loren, since it was accidental, it really wasn't a murder
Unfortunately, same results though...
I have both the Pacific and the mike, and for the life of me can't understand the logic behind the design. Between it, and the boiler made of cryptonite, these must be the most kitbash resistant steam locos in N scale, ever! Too bad, too, they look like a good start for many projects...
Otto K.

[mmagliaro]

Loren, since it was accidental, it really wasn't a murder
Unfortunately, same results though...
I have both the Pacific and the mike, and for the life of me can't understand the logic behind the design. Between it, and the boiler made of cryptonite, these must be the most kitbash resistant steam locos in N scale, ever! Too bad, too, they look like a good start for many projects...
Otto K.

I think the trick to them is to utterly and completely disassemble them, and get rid of the wire routing that runs  through the cover plate an always breaks off.  You could get rid of it entirely, and the driver wipers, and let it run on the tender alone if you put Kato tender trucks in it.   But I am not a fan of that.  Relying on only the tender never quite cuts it with enough pickup for me.  But I did a mod on one of the 4-6-2's that gets rid of the breaking wires problem, here:
https://www.therailwire.net/forum/index.php?topic=33883.msg391152#msg391152

On that engine, I couldn't fix a badly slipping driver (one of the MP 4-6-2's other Achilles heels), but I did solve the breaking wires issue.

[Mike C]

 I have 1 I haven't used in a couple years that I would let go for a fair price . It has a Bachmann tender and a Digitrax decoder . Runs smoothly and at scale speeds is pretty quiet , just a bit of worm whine . ...Mike