I have a 1:20.3 spectrum 4-4-0 and it stopped moving - cracked axle gear, I thought. (I already replaced one on my 2-6-0.) So I ordered the replacement axle from Bachmann Parts and got on with the surgery
Imagine my surprise when I realized it wasn’t the axle - it was the first gear pair and the spur on the worm was completely worn away!

For the moment I put it back with a washer to force it to mesh, but that won’t last long, and I’m not sure I can be bothered to put the whole loco back together if I can get another gear.

Anyone know where I can get a replacement? The whole motor/gearbox pair is available, but for $50.40.

The gear looks just like the one on the axle, but different shaft and the extra spur attached to it. Guess I could pin the axle gear to the smaller spur gear and use some brass tube in the hole. . .

I measured the axle gear and it is about 0.62" diameter and 25 teeth, but this one from Bachmann has a flat on the axle so the gear has a “D” hole in it to match. (I think that’s new?) This bad spur/worm gear is 0.60" and 24 teeth. Maybe one of those NWSL 24 tooth gears would work.

At first I thought the new axle I purchased a few months ago from Bachmann Parts is different from the one in the loco. But it isn’t (I took it out and photographed it if you want a side-by-side.) But I don’t recall the NWSL gears having that “D” shape center. I’ll have to check when my pal gets back, as he has one.

Did you contact TOC for the gear?

Greg

Pete, the worn-out gear looks to be the same as the first gear in the 2-8-0 gearbox. Wouldn’t at all surprise me that they’d use the same gears.

With regard to the “D” hub on the axle gear, that’s a new one on me. I’ve only seen circular openings on Bachmann 4-4-0/2-6-0 gears, but–again–that Bachmann might change a design and not tell anyone wouldn’t surprise me. They’ve done it before. Props to them for making the change. It’s not going to spin on the axle like that, that’s for certain. It may break clean in half, but it’s not going to spin. Shame they don’t make the new brass gearbox available. That’d be worth the money, for certain. Still, $50 isn’t bad for the full assembly, especially with the motor attached.

Later,

K

With NWSL announced as coming back to life maybe that might be an option to source a replacement from. Interesting about the "D"shape on the main axle drive gear. The pair of replacements I bought from Bachmann as a precaution, when they had them in stock about 4/5 years ago (flagged by a poster here, thanks), were still the old full circle design. I’ll have to keep a weather eye open for this new gear failure you have regrettably suffered Pete.

As an aside I experienced a near identical failure, same transfer gears meshing with the primary worm gear on the motor shaft, on a UK (hand)made gearbox for a 1:19 scale electric NG loco - but that was an all metal box. The supplier eventually, somewhat grudgingly, replaced the whole gearbox after 2 botched attempts to piecemeal replace individual gears, resulting in further failures in short order. Turns out there was a basic manufacturing error in the positioning of the gears’ shafts. But I guess the supplier was more interested in profits than customer service.

Greg Elmassian said:

Did you contact TOC for the gear?

Yes, thank you for the suggestion.

Kevin Strong said:

Pete, the worn-out gear looks to be the same as the first gear in the 2-8-0 gearbox. Wouldn’t at all surprise me that they’d use the same gears.

K

Good point. And guess what - they have the complete gear set listed for the 2-8-0 for $11. Thanks - I’ll get one as I bet the gears are the same.

http://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=66_69_142&products_id=10630

That big gear top left even looks like it has angled teeth? Aha - that gear is also available for $3.30. Looks like I am saved!

https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=69_142&products_id=9646

Darn it - they are all listed as “SOLD OUT”.

P.S. Apparently all 3 gears in the 2-8-0 gearbox are available as spares, among the 183 (count 'em, 183) parts for the 2-8-0. A treasure trove of sand domes, lights, wheels, trucks, etc.

Max Winter said:

With NWSL announced as coming back to life maybe that might be an option to source a replacement from. Interesting about the "D"shape on the main axle drive gear. The pair of replacements I bought from Bachmann as a precaution, when they had them in stock about 4/5 years ago (flagged by a poster here, thanks), were still the old full circle design. I’ll have to keep a weather eye open for this new gear failure you have regrettably suffered

My 2-6-0 didn’t have the “D” axle and is fitted with a NWSL gear. I have asked them for a 24-tooth gear, but they are in transition to the new owner at the moment.

Both the new (bought this year) and old (what was in the loco) axles on my 4-4-0 have the “D”, so I wonder if the replacements from Parts are with the “D” and this loco was already ‘fixed’ before I got it. Shows no wear on the axle gear, despite the worn out spur gear.

Kevin Strong said:

Pete, the worn-out gear looks to be the same as the first gear in the 2-8-0 gearbox. Wouldn’t at all surprise me that they’d use the same gears.

With regard to the “D” hub on the axle gear, that’s a new one on me. I’ve only seen circular openings on Bachmann 4-4-0/2-6-0 gears, but–again–that Bachmann might change a design and not tell anyone wouldn’t surprise me. They’ve done it before. Props to them for making the change. It’s not going to spin on the axle like that, that’s for certain. It may break clean in half, but it’s not going to spin. Shame they don’t make the new brass gearbox available. That’d be worth the money, for certain. Still, $50 isn’t bad for the full assembly, especially with the motor attached.

I note you can buy the replacement 2-8-0 axle with the brass gear, and I assume (dangerous thing to do) it is the same size and 25 teeth. I wonder if you could tap it off and mount the brass gear on a 2-6-0/4-4-0 axle.

Since you are looking to buy the whole set of gears, my post is probably moot. But the axle gear will not work in place of the worm gear that meshes with the worm on the motor. As you pointed out the teeth are angled.

David Maynard said:

Since you are looking to buy the whole set of gears, my post is probably moot. But the axle gear will not work in place of the worm gear that meshes with the worm on the motor. As you pointed out the teeth are angled.

Can’t buy the gears - “sold out”.

You’d be surprised what will actually work. (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-cool.gif)The worm would probably grind the NWSL gear into the right shape. (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-foot-in-mouth.gif)Or I could grind the thickness down a bit.

Anyway, I seem to have another solution - actually up to 3 so far. Dave has found a spare in his parts box and it is on the way to me. And Jerry Yeramian has offered to machine a duplicate for me. (Jerry hangs out on Facebook and has made several gears for various locos for various guys.) I’ll send him the “D”-type axle gear too and ask him if he can reproduce that, as the NWSL is sifferent. [Note: maybe, if B’mann is providing a different type of gear on the replacement axles, then maybe, just maybe, they used a different plastic that won’t crack?] Not sure how he would machine a “d” center hole.

The 3rd solution is to wait for Bachmann to get them back in stock or buy a complete motor-gearbox.

Progress is noted on the replacement gears:

On the right is the spare I obtained from Dave. On the left is a copy produced by Jerry Yeramian. I’ll be testing it later this week and will let you know how it works.

So, what is the cost to a normal human for a replacement gear?

Greg

Greg Elmassian said:

So, what is the cost to a normal human for a replacement gear?

Greg

Jerry says he made 6, and I have 3 of them for which I paid him $75 incl shipping. If they work (haven’t arrived here yet due to holiday) then I imagine that will be the price - $25/each. [I actually did not need to do this - the white gear on the right in my photo was given to me and will solve my problem. But I have a 2-6-0 and my pal has a 4-4-0. . . .]

Which is not inexpensive, but it will get my 4-4-0 moving again, I hope. However, if it is the same, the 2-8-0 gear 0AY01 is $3.30 if they ever restock.
https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=69_142&products_id=9646

On the other hand, the complete gearbox and motor is only $50.40, but without the axle which is $6.60.
https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=69_145&products_id=6912

A bird in the hand is worth 2 in the bush?

I did not see you mention it explicitly, is it delrin?

Greg

Greg Elmassian said:

I did not see you mention it explicitly, is it delrin?

Jerry.says yes - delrin.

Pete Thornton said:

Progress is noted on the replacement gears:

On the right is the spare I obtained from Dave. On the left is a copy produced by Jerry Yeramian. I’ll be testing it later this week and will let you know how it works.

It works! I had to open up the hole very slightly on the new part, but the loco is now back in action thanks to Jerry Y. He’s on the Facebook groups, but message me if you want his email.

Jerry finally got back from his epic trip to Stavers, Sacremento for the NNGC, etc. So the 4-4-0 got to stretch its legs and demonstrate that the gear works and is quiet.