Large Scale Central

Bachmann 4-4-0 gear splitting

I have one of the older, but bought new by me, Bachmann 4-4-0 that has only been run a very little. But I heard over the years how the drive gear will just split sitting there. So I want to plan ahead and be prepared. How is the Bachmann replacement working out. I read where it is a D shaped but did that solve the cracking issues? Does anyone else even have replacement gears?

The gear splitting (common to ALL older Bachmann engines) is due to gassing out of the plastic that was used, not the method of drive.

Jiro Yeramian machines replacement gears for many G scale locos. You can contact him on FB Redirecting...

We don’t know yet. They certainly work and are not expensive to buy so we hope they’ll be good for 10+ years. Buy a spare?

Jiro doesn’t have the 4-4-0 or 2-6-0 gear as far as I know.

I just noticed the axle gear for the D shape axle is all of $3.57 and is listed as available. Might be good to buy a couple of spares!
https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=69_75&products_id=11565

I did the same a couple of years ago. I also understand you could try here https://nwsl.com/ Max

Does anyone have any pics of the split gear?

This is from the thread I posted when I changed out a gear recently.

NOTE: this gear is the old style and fits on the knurled axle. The NWSL gear will fit this axle - but won’t fit the new style with the flat “D” section:

As mentioned above, spare gears and complete axle+gear are available in the Bachmann parts store.

So it’s “SPLIT” I thought maybe it just cracked.
Thanks Pete

Some crack, some split. I just did a 2-4-2 with a crack on one side, Tim has a 0-4-0 with a completely split gear. We did a 4-6-0 gear that was cracked but only on one side.

It seems totally random whether the whole gear breaks or just one side. Might be something to do with how much use it is getting - if it sits on a shelf and never runs, maybe they split? Who knows.

Get the new Bachmanm gear on a D shaped mount axle. But don’t throw away the old splined axle, as you can get an NWSL replacement. I understand they use Delrin not just a cheap nylon moulding. Then you are covered now and in the future and have a spares option when the time to sell or pass on arrives. Max

The old Bach stuff is plastic press-fit. Due to the extremely high quality in engineering, the cast plastic starts shrinking as soon as it’s made. The NWSL is machined Delrin, won’t shrink, not seen one crack yet.

If the new Bach design D gear is loose on the axle, probably not a high likelihood of splitting. But, being Bach, never put it past them.

Give you some idea of the extent of the fiasco, the outside-frame 2-8-0’s…I have done probably hundreds of them, conversions and repairs…and I have NEVER dropped the bottom cover off one and found an axle gear NOT cracked at the hub. Every one through here. In fact, I have (I think it’s) two new ones in the box in the basement, inspected (roll the drivers with thumbs) with the special factory split gears. I’ll put NWSL gears in prior to sale.

I used to have a stack of split gears threaded onto a piece of wire to show folks.

Since they had such trouble engineering stuff, I quit buying anything new from them long ago. If I need something, I buy USED at a fraction of their list price, and fix it.

Never had one of the 4-4-0 or 2-6-0 D axle types here.
The only issue I could see is the sharp corners in the D of the gear and the force twisting it on the axle.

TOC

I cant find this dang gear on the site, am i blind or…

(Brett, are you also ziplocBag on MLS?) I just posted this reply to a similar question on that other website.emphasized text

I believe they are 25 tooth. NWSL #2226-6 I think, for the 2-8-0. I recently emailed them and they confirmed they can supply them.
(On the website, look for Old Catalog Pages and then Upgrade and Replacement gears. Large scale is right at the bottom. I asked them to correct their info but I don’t think they are updating Old pages!)

Bachmann is sold out of the new gear on the “D” axle, but they do show the nylon gear, which might last a few years.
Axle Gear G Scale /Universal/2-8-0/-2-6-0/4-4-0 ) [813XX-13-A] - $3.68 : Bachmann Trains Online Store!
note that Bachmann says that gear fits the 4-4-0, 2-6-0 and 2-8-0, which clarifies the issue of which one fits.

On a FB thread about the 2-8-0, Mike confirmed the brass gear on the 2-8-0 replacement axle also fits (and is available.) Only works on the old splined axle and you have to be careful tapping the brass gear on and off the axles.
Axle with Brass Gear (Large Scale 2-8-0) [G813X-AXELBG] - $12.26 : Bachmann Trains Online Store!

I’d suggest the NWSL or the brass gear if they no longer have them. I have a spare, somewhere, if you get stuck.

Hope that helps!

Yes! i did find the NWSL gear when i seen your reply on the other site (i seen you there first) the plastic gear would seem easier to work with and help with gear noise, so i chose that, Thank you so much for your help.