Climax replacement gears

[jerryl]

   I know Bachmann states that the have no replacement parts for the 2 truck Shay, but it seems to me that most parts in the new 3 truck Shay would be the same.
   I don't think I have the split gear problem, unless it's completely split.  There is only movement in the rear truck. The gear could just be spinning on the axle.  I hear that they replace them with a Shay...Don't want the Shay & they seem to have the split gear problem also.

[richg]

   I know Bachmann states that the have no replacement parts for the 2 truck Shay, but it seems to me that most parts in the new 3 truck Shay would be the same.

DID YOU MEAN CLIMAX IN THE ABOVE?

   I don't think I have the split gear problem, unless it's completely split.  There is only movement in the rear truck. The gear could just be spinning on the axle.  I hear that they replace them with a Shay...Don't want the Shay & they seem to have the split gear problem also.

THERE ARE GEAR PARTS FOR THE TWO TRUCK CLIMAX. I SAW THEM LISTED

Rich

[jerryl]

  Thanks, last I heard they were unavailable.

[richg]

Well, lets put this way. I see the parts posted and they "seem" to be in stock.
Try to order. You will no doubt get a reply either way. Seems obvious to me.

http://estore.bachmanntrains.com/index.php?main_page=index&cPath=66_68_153

Rich

[Ken Huck]

I just received a set of gears, etc. but, have not tried to install them yet.  They are not a 'drop in' fit.  The new gears have a 'raised' ring of reinforcing plastic on the back- side to prevent splitting.  This makes the exposed shaft portion 'shorter' and won't fit into the truck.  If you plan to shave off the raised reinforcing ring then you will be right back where you started.  What I plan to do is remove a gear at one end and remove the bushings and grind the bushings down the same depth as the raised reinforcing rib.  The bushings are used to 'center' the gears and length isn't a problem.  When you disassemble the trucks you will see what I'm talking about.  BTW, it only took about 4 days from the time I ordered the gears until I received them with daily e-mail updates about the status of 'my order'.

HTH

Ken

[LooseClu]

After three trips to Bachmann's Philly shop they declared my old 2-truck HO Climax irreparable and offered me a new 3-truck Climax to satisfy their warranty.  On the first and second return they offered a 3-truck Shay and like you I already had one so turned the offer down.  Now that they have the 70 ton 3-truck Climax available that is their exchange offer.  I've already converted it to a 2-truck (easily done) but it is larger than the original 2-truck- it's taller than the 3-truck Shay. 
Roy

[AMACH]

I had two shays that did not appear to have split gears, but when I carefully examined the pinion gears under a microscope I discovered that they had expanded causing the tooth spacing to distort and expand. This makes the pinion jam against its mating gear at one point around its 360 degree rotation. Or you notice a jerking motion as the loco goes down the track.

I agree with comments below that Bachmann is very responsive with repair parts and warranty replacement offers.  Every Climax and Shay that I have has split their original pinion drive gears. The new style gear with raised ring reinforcement does help. As stated elsewhere, if you trim this ring you will defeat the purpose of the reinforced design.

All plastics are fugitive materials that tend to creep or flex when placed under a mechanical stress load. That load typically does not come from driving the locomotive down the track. Rather it comes from the press fit of the gear over the knurl or spline on the steel drive shaft. The press fit causes the plastic gear to expand a few thousands of an inch which eventually distorts or cracks the gear. Plastics can cross-link with age like old human skin or aged car tires. Cross-linked polymers become brittle. Overall the gear problem is really a materials engineering problem in my opinion.

But in Bachmann's defense, if they manufactured the gear from better plastic material or metal the final product cost goes up. All products are built to a price point adjusted to market competition.  I guess it is sacrilegious to mention on this forum that Northwest Short Line makes replacement metal gears for Climax and Shay. I have used these as permanent fixes for the gear splitting problem but I also have a jewelers lathe that allows me to precision fit the gears to the shafts and trim gear back-face or bronze bushing clearance to achieve proper gear mesh which is vital to smooth performance. This almost gets into micro machining. Most owners simply want to glue on a new part and run.

However you decide to effect repair, I believe it is worth the trouble. It is a real joy to see the miniature mechanical motion of a Shay or Climax winding it way around your layout. These locomotives are a very unique part of railroading history.