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SPECTRUM 4-8-2 GEAR PROBLEM

Started by breezy8, September 20, 2017, 04:25:40 PM

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breezy8

I have a SPECTRUM 4-8-2 and it seems that the WORM GEAR and the DRIVER GEAR are NOT making contact.....Decoder works fine, but it is FREE WHEELING ( no gear contact) I can turn the drivers easily. Any ideas as to a solution to this????  Any help would be GREAT....TONY  AKA breezy8

jonathan

The 4-8-2 Mountains have a cog belt that connects the motor to the worm.  That would be the first place I would look. 

However, if wheels turn freely as you say, either the plastic main drive gear is stripped, or the worm has slipped out of its brass bushings.

Can't see your model, so hard to diagnose.  You will have to disassemble to get a good look.

Hoping its the belt, as belts are easier to replace than other repairs.

One last thought... There is a plate under the frame that holds the drive wheels in place. Are the screws loose by chance?

Regards,

Jonathan


jonathan

#2
Another thought:

The easiest place to start is turning the locomotive upsidedown, in a cradle or otherwise held securely. Removing the bottom plate is a matter of removing several screws that hold the plate in place.

Be careful.  You don't want to lose the screws or damage the parts that hold the wheels in place.  However, with this plate removed, you will be able to see the drive gear and perhaps get a peek at the worm gear.  At a minimum, you will be able to see if the main gear is stripped.

Any other searching will require removing the shell and opening the split frame to get a look at the motor-to-main-gear assembly.  If you've never done this before, it can be a bit daunting at first.

Since the mountains are long out of production, parts may be difficult to come by. I notice that the parts department still has motor assembly and drive wheel assembly parts available for both the heavy and light mountain.

The mountains are among my favorite Bachmann locos.  I have two and run them all the time.  I've replaced a motor in one and a cog belt in the other.  I've posted my work on them, but the photos were photobucket and no longer appear in the posts.

Regards,

Jonathan

breezy8

Jonathan, The worm gear is brass and the belt is in good shape. I will remove the plate and see if the wheels are setting where they are supposed to be. That may be what I am looking for. The gear on the axil LOOKS ok...not striped....I have pulled the shell off so many times in the last 2 days, I did it in my sleep...LOL....I will let you know what I find....THANKS...TONY  aka   breezy8

breezy8

   Jonathan, I found my problem. The main gear on the drive axil was spinning on the shaft.  I could hold the gear and spin the drivers....A drop of super glue where the gear and shaft meet and  WOW....IT RUNS LIKE A CHAMP.  Thanks for your thoughts...and help...TONY  aka  breezy8

Trainman203

Mr.  Bach Man

Those mountains were among the best ever made.  Please re introduce them ..... WITH the beautiful separately applied detail parts.

jonathan

Glad you found the problem.  Hope the superglue holds for a long time.  If it fails, at least there is a driver set available. And it sounds like you are handy with disassembly.

Yep, those USRA Heavy Mountains are great locos! Likewise, I really liked the original USRA 2-6-6-2, with the square tender.  Still kick myself for never getting one.  Still want to do a KK-4b or KK-5 kitbash of that baby, if I ever run across a good deal.

Regards,

Jonathan

Trainman203

Jonathon , as time goes by, I realize that the time period of Spectrum steam engines was a high water mark in model railroading. There were so many engines, so beautifully detailed. In my favorite southern road names, no less.   I have at least one of most of them , though not the articulateds.

It speaks to the decline of our hobby that they turned out in the end to be a money losing deal for the Bach Man.  I don't expect to see them again and will miss them, although my biggest worry now is parts.