Large Scale Central

Bachmann 25 Ton (old verson) truck gears - help

General Discussion
#1

Hello friends,
I recently purchased a Bachmann 25 Ton Climax (old style) off ebay (of course). I ended up cleaning out the gear boxes because they were filled with a white waxxy like stuff (likely original grease). I also noticed that part of the gears in one of the trucks were blackish colored. My guess is they had been replaced in at some time in the past (similar color of NWSL gears I bought for my Shay in times past).

Now, after running for about 4 hours I noticed that on both the front and rear trucks only had one set of wheels turning at power up (I am running DC). The gear (on the coupler side), on both trucks, the one below the worm gear is going smooth, teeth are worn so much that the brass worm gear does not turn the next gear down.

Any recommendations on finding a replacement or point me to someone who can make these gears would be greatly appreciated.

Sometime back I saw either a Bachmann Climax or Shay on ebay with a full set of brass gears in it (oh to dream) - if anyone know who this might of been, would you let me know.

Lastly, maybe way out there, but - is there a way, like recapping a tire to repair the teeth?

Many thanks for any advice on repairs or replacement.
Jerry

#2

Any recommendations on finding a replacement or point me to someone who can make these gears would be greatly appreciated.

Jerry,

Take a look at this thread:
http://www.largescalecentral.com/forums/topic/29767/a-different-spectrum-4-4-0-gear-problem

I have noticed that Bachmann tends to re-use the same gears in different locos. It may be that the gear below the worm is the same size as the gear I had made for my 4-4-0 by Jiro Yeramian. Jiro can make gears with slanted teeth to mesh with a worm, so even if it is not the right size, he might be able to make one for you.

Did you post a similar thread a few weeks ago with a photo? Maybe on Facebook? Do you have any photos of the worn gear? Can you identify it on this photo from George Schreyer? http://www.girr.org/girr/tips/tips5/climax_tips.html

#3

I’ve never seen an all metal gear solution (I assume it is the internal gears, and not the ones in the sideframes), but it was not factory.

NWSL has completed their ownership changeover and physical move, but a quick perusal of the online store does not show any parts for the shay.

There is a gentleman on Facebook, jiro yeramian who has made custom gears for some people…

Best bet is to try to locate replacement trucks that were sold by Bachmann as a “kit” of 2 complete trucks.

No you cannot “recap” a gear…

Greg

#4

I didn’t know Bachmann sold Climax trucks.

#5

Whoops, heisler and shay same, climax different… SOL…

This page has picture of the gearbox… http://www.girr.org/girr/tips/tips5/climax_tips.html (same as link posted earlier)

Bachmann lists the gearboxes for sale, here is the center one, $66

https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=69_641&products_id=8295&zenid=ic0mh5c5toftep3109d8lmk4f7

#6

I was teasing Jerri @ our Christmas party " The Gear Man " last week …(https://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-laughing.gif)

#7

Hey all,

I have been trying to figure out how to post of pictures inside the reply (not quite there yet). I did post an album that has the pictures I would add (if you hit my picture I think it takes you to the albums). I know it is a pain, but you can see the album at least.

Pete - not my posting on facebook (I do not have a facebook account) with the white packed grease in the gears but my trucks looked like that but a bit more yellowish and the grease had the consistency of melted birthday candle wax.

Now that I cracked open the gear box, I realize there is more to the story than meets the eye.

  • Purchased engine was very dirty on the outside and as indicated the trucks looked like they were full of goo.
  • Cleaned the engine and manually removed the goo with dental tools. All four of the worm gears were in good shape at that time. (If you look in the album, the 3 ate up gears looked like the one good gear remaining)
  • I did the truck to frame connection mod as from the GIRR.org tips page.
  • I ran the engine on my a track with Bachmann E-Z riders for about 30 minutes. I noticed it took a bit more to get it going than my other climax. I figured it just needed to break in a bit.

So I ran it on my outside Christmas display (you can see my log train in the album pictures)

  • Ran for about 4 hours with no issues. It was run at a moderately slow speed but required more voltage to pull the train than my shay needed.
  • There is some grade to the log train track but not huge
  • After I ran it with the log cars I at the end of the night I took the cars off and ran the engine. It made it about half way around my track and stopped.
  • I just blew it off thinking is was dirty track or a leaf etc.
  • I felt the trucks. They were slightly warm but not hot.
  • Next time I went to run it it would not move.

After you asked for pictures is when I removed the trucks and looked at from the bottom, but the real destruction was not seen until I removed the trucks and opened the top. (look in the album for the pictures of the trucks)

One truck has had work done in the past as I can see black colored gears in it like the ones that come from NWSL.

I have no idea what tore up these gears.

I wonder if the goo was still in the trucks and was bogging them down or it was stickier than I thought where the axles when through the truck wall.

Did they overheat eating up the gear, does not seem likely as it is only the worm gear that is damaged.

Still need to replace these gears. I am hoping as others pointed out that I may be able to cannibalize a couple old 4-6-0 chassis I have for the gears…we shall see.

As I am dumbfounded at both why this happened and what to do next I am looking forward to your thoughts.

Thanks

Jerry

#8

Jerry, you can see the part numbers for the individual gears in the “product reference” section on the Bachmann site, drill down to get to the front and rear gearbox pages…

Now you can find if any of these gears are common, by looking at the part numbers from other bachmann reference sheets.

I don’t think Bachmann sells the individual Climax gears separately, just the assembled gearboxes.

In any case, the information is there to determine if you can find a common part number, and thus a “donor” loco.

Greg

#9

Here’s your pic Jerry. [Just right-click it from your album, select “copy image location”, come back here and use the picture icon.]

So on the right is the gear chain to the axle, and on the left is the gears to the axle and to the yoke coupling to the center drive shaft. [My understanding is that only one truck drives the gears and cylinders - the other has no connection to the yoke on the shaft that is driven by the other truck.]

The gear is not the same as the one on my 4-4-0 (which has a side gear,) but it is close in size. If you can get the good one out, send it to Jiro Yermanian and ask if he can reproduce it in Delrin. (Note that he charges $25-ish and prefers something that other folk might need - I think this one meets that criteria.)

Did they overheat eating up the gear, does not seem likely as it is only the worm gear that is damaged.

My 4-4-0 gear looks just like that. My suspicion is that the plastic is soft. Maybe they had a bad batch of plastic and only now are we finding them.

I would also suggest posting this on the Bachmann Forums. There are several folk over there who have more experience with this kind of issue. Greg’s comment that you might find a common part my checking the exploded diagrams is a good one too.

#10

Be sure to check that the other undamaged worm gear is not slipping on the axle… perhaps the axle with the damaged gear was getting all the load.

Greg

#11

Pete,

Thanks for telling me how to post…of course to easy wouldn’t you know.

The motors appear to be running fine. The one good gear turns like it should and the others do not although the worm gear is spinning.

So my final speculation on how they destroyed themselves.

  • Remember I told you I cleaned out the waxy grease stuff…
  • I suspect it was still up in the gears. The axle with the remaining good gear seems to turn very easy. ( the destroyed gear actually floats on the shaft it is not anchored).
  • The others seem stiffer to me a take more force to turn.
  • So the wheels were all likely turning at different rates, the good gear was over driving the ones that were not turning and since they would not turn as easy the brass gear had to really drive into the plastic which likely failed due to the force being placed onto it.

This gear should really be brass… the first gear off the worm takes all the force. Again, I believe these trucks were previously worked on since they have a few black gears in them that appear to be made of “Delrin” which is what NWSL used instead of soft plastic. Delrin is some good stuff since it is a resin that performs like metal.

I have two sixth generation 4-6-0 big hauler chassis (one under a Liberty Bell and the other on a Northern Express). These have all brass gears and I suspect they will last a lifetime.

I have replaced gears in my Shays, but the pins in the Climax trucks may take some work to get out. We shall see.

If I find a matching gear I will share but may end up reaching out to Jiro.

Thanks all.

Jerry

#12

Actually you cannot have a worm and a worm gear of the same metal, you will get galling and the gear will destroy itself.

Kind of interested how you state that one axle turns easily and other turn hard.

The axles should not rotate under pressure at all… if they do, the axle gear is slipping on the axle, or something is really ground to bits

These are “single lead” worms and will not rotate the motor if you apply torque to the worm gear.

Greg

#13

you will get galling

I had to look that one up. Galling that I had to do so.

Jerry, the comments made by Greg are valid - you shouldn’t be able to turn the axles as the worms won’t be ‘driven’ by the axle gears. As I said earlier, it isn’t clear why some Bachmann gears shred like yours (and mine.)

#14

https://en.wikipedia.org/wiki/Galling

#15

Guys,

Thanks for the notes. Very interesting…learning a lot.

Need to clarify my earlier note: The good gear turns very easy on the axle when power is applied to the motor. The others seem to drag and my assumption there is likely goo between the gear and the shaft it rides on causing it to bind or drag in some manner. As the motor did its job the stress of not turning easily or dragging is what may have ate up the gear.

In the reading it states: Galling is a common problem in most applications where metals slide while in contact with other metals. This can happen regardless of whether the metals are the same or of different kinds. Alloys such as brass and bronze are often chosen for bearings, bushings, and other sliding applications because of their resistance to galling, as well as other forms of mechanical abrasion.

Now realize I have a degree in Marine Science from a military academy nearly 35 years ago, as such, my conclusions are likely “wacked”

So the idea behind the brass gear would probably give the gear box far better longevity than the plastic gear. As a non engineer, doesn’t the angle of the teeth and the supporting gear also play into the reduction of the galling.

I could not get a good picture of the gearbox, but the gear box below is from a Bachmann 6th Generation 4-6-0 it is all brass gears including the worm and its supporting gear.

I am hoping I never have to mess with this gear box and it will become my grandkids problem…

#16

Need to clarify my earlier note: The good gear turns very easy on the axle when power is applied to the motor. The others seem to drag and my assumption there is likely goo between the gear and the shaft it rides on causing it to bind or drag in some manner. As the motor did its job the stress of not turning easily or dragging is what may have ate up the gear.

Jerry, for more clarification - we assume the gear turns the shaft it is mounted on when the motor turns? It’s not clear from your description " gear turns very easy on the axle". It is also desirable that all the shafts turn easily when the motor turns.

Yes, if there is drag it can cause the gears to get chewed up like yours. But it isn’t clear which one is dragging - any of the shafts could be the culprit and could cause the problem. You can’t tell by watching one shaft. I’d be inclined to take the offending gearbox apart and see what is going on.

#17

I agree with Pete, I am still confused about what you are telling us. Literally you say the gear turns easily when power is applied… how can you know that? since the motor is engaged, how can you evaluate the friction on the axle?

Disconnect the motor and see how freely each of the geartrains turn, everything should turn freely without the worm engaging the worm gear.

On galling, the key is the SAME metal under pressure and sliding on 2 engaged gears… as gear teeth engage and disengage, they do slide. You will never see a worm and worm gear of the same metal, one will always be a harder metal too, normally the worm since it is smaller. So when you said ALL brass gears that brought out my comment. Due to the small contact patches, the side thrust, etc, the worm and worm gear are normally the most stressed.

Greg