The Problem

These locomotive use a complex gear train and drive mechanism. There are numerous points of failure, however Bachmann has in their parts catalog the necessary repair pieces to get these running again.

The first point of failure is the gearing in the trucks 

The small pinion gears will split and then will not mesh correctly. Also the plastic u joints also split and will spin on the shaft. 

The next area of failure are the drive shaft u joints

These split and then will simply spin on the drive shaft.

The third area of failure is the gearing inside the gear box.

These parts are common to both the 3 truck and 2 truck HO models. The On30 model also uses a similar design, however I haven't had the need to take the On30 one apart, at least not yet.

Truck Replacement

The simplest, and probably most effective solution for the split gears in the trucks is to order new ones from the Bachmann website.  https://estore.bachmanntrains.com/index.php?main_page=index&cPath=68_689&zenid=co7oq3u4j4mu473hfioii7r8o7

Make sure that you order the ones with metal gears, they do still show some of them with plastic gears, if you order those they will probably come with the gears already split!

The trucks simply snap off and new ones are easily snapped on after lining up the drive shafts. 

Alternatively you can attempt to repair the truck gearing by purchasing the gears, and drive shafts. This doesn't always work out as the new gears don't always mesh perfectly with the old gearing. You can purchase the gears themselves or the gear and drive line assembly.

If you are lucky, this might solve your problem and the locomotive will run properly. However it is unlikely to fix things permanantly as the other issues with the drive train will show up eventually. I will talk about them in the next post. 

Drive shaft Replacement

The next item that is easy to repair is the drive shaft. The bottom of the gear box is held in place by 2 small screws. Open the gear box up and remove the drive shaft assembly. Sorry for the fuzzy picture.

You can order this part from Bachmann, the new ones have metal gearing. On my 2 truck Climax the front drive shaft was too long and I had to file down the end a bit to allow the front truck to swivel properly. The 3 truck one seems to have a little more space here and the shaft fits OK.

You can also get a metal gear to replace the one that is connected to the valve gear. You can see this in the picture below with the large gear. I purchased these replacements, but so far the plastic gears have not split so I haven't needed to replace it. I will keep the replacements on hand for the day that they do split!

The Easy Part is Done!

That was the easy part, the next gear that needs replacing is inside the gearbox. It is easy enough to replace, once you get to the gear box, but getting the gear box out and especially getting it back together again is a major effort!

First step is removing the trucks and bottom gear box cover. Then you need to remove the boiler and cab, but try to keep the cab and boiler together, there is a bunch of piping and other details that run between the cab and boiler that you don't want to remove. In general the less you disassemble the better as these are complex models!

Remove the screws holding the cab on and th boiler in place. There are a couple screws holding the cab in place and 2 screws holding the boiler. One of those is shown in the photo below.

This should lossen the boiler from the frame, but there will be various bits of piping and wiring that might prevent you getting full access. Search for those and remove them. If the wiring is really tight, as it was on my 2 truck version, you might have to remove the circuit board in the tender to give you some slack in the wires. On the 2 truck, the headlight wires are routed through a plastic plug in front of the motor. I had to get some needle nose pliers in there and pull that plug out to loosen things enough to remove the boiler. Keep track of all these small screws, they are all different sizes and need to go back in the right spots when you re-assemble it. The 3 truck version was much easier to work on, it has a little more space around the boiler! I have no idea how they managed to assemble the 2 truck version in the factory, I had a great deal of difficulty getting it apart!

Now that you have the boiler off, you can remove the motor. there is a plastic clip over the worm gear that snaps off, you might have to move some wiring out of the way first. Then there are 2 small screws that hold the motor in place, remove the motor and the motor support.

 Boiler off showing the motor, you need to remove that small circuit board off the gear tower first.

  Ok now we need to remove the gear box. With bottom of the gearbox open you can remove the drive line and pull the gear shaft that is attached to the valve gear. Be very careful here, I broke part of the valve gear on my 2 truck Climax and still haven't figured out how to fix that.

Now with the loco upside down remove the 3 screws holding the gearbox in place and tilt it up and out of the chassis.

Gearbox

Ok that was hard! Now there are a couple of screws holding the sides on the gearbox, open up the gearbox, one side has a bunch of gears, that side should be fine, but while you have it open clean out any hardened and excess grease and, if needed, put a small drop or 2 of oil on those gears. They probably don't need any, they are usually swimming in grease and oil.

The other side has a gear on a shaft, this is the one that needs to be replace with the metal gear that you get from Bachmann.

Pry out the old gear, you can probably spin the gear on the shaft, which explains why there was no power getting to the wheels!

Put a couple small drops of oil on the new gear and reassmble the gear box.

Now for the Hard Part!

Now we have everything repaired, but we have to get it back together again! I can't help you much with this, it is not easy and can get frustrating. Watch for wires and especially the truss rods that get caught when you try to reassemble it. I had to take mine apart several times as some wire or the truss rods on one side or the other would get caught in between the gearbox and frame. Try not to damage the valve gear assembly as this is floating around loose while you are doing this. Once you get the gearbox back in place, attach the motor and then the valve assembly and drive line and close up the bottom of the gearbox. 

Now to get the boiler and cab back on it helps if you have about 5 hands with really skinny fingers. Again the 3 truck one isn't too bad, the 2 truck version is next to impossible!. I actually gave up on the way that the wiring ran on the 2 truck one, I could not get it back in place and get the boiler back on. I finally just pushed the wires up into the boiler above the motor and after numerous attempts, a walk in the park to calm down and then returning some hours later got the thing back together.

Hopefully you succeed in repairing yours. I have done 3 of them now, one 2 truck and 2 three truck versions, so it can be done. I would suggest ordering the parts ASAP while Bachmann still has them in stock. I order a few extras just in case.

Hm...

"How to Repair A Bachmann Climax."

Viagra?

Andre

The next bugbear with those

The next bugbear with those Bachmann Climax locos:

This combination pinion/spur gear often lost it' correct meshing. Therefor the pinion part is subject of abrasive wear caused by it's counterpart. The depth of tooth can be reduced so far that a meshing became impossible. To remedy this it is possible to shim this combination gear with suitable washers. The washers should be so thick, that a proper mesh is enabled. Meanwhile i have repaired a dozen B'-man Climax in H0 and 0n2 and half of the H0 Climax has had this additional problems in the center gearbox.

The small spur gear on this shaft was also replaced with a metal one.

my 2 Cent

Lutz

Haven't Seen That Problem, Yet!

Lutz,

I haven't see that problem, at least not yet! I hope I don't have to take mine apart again, but I guess after doing it 3 times on three separate engines, I should be getting good at it!

Question re -newer- Climax locos

Just wondering, but how are the -newer- Bachmann 2-truck Climax engines (the ones with the metal gearing) holding up...?

New Versions

I do have one of the newer 2 truck Climax, so far so good, I haven’t had any problems with it. I have had it for a year and a half. Use it as a switch engine. Haven’t put sound in it yet, that is a project that needs to get done, it’s somewhere on the list, just have to decide if the Tsunami 2 will fit, or use a Loksound mini. I don’t like the crippled Tsunamis that Bachman sells for it.

I have a 3Truck that is about

I have a 3Truck that is about 5 years old.  I just replaced one of the truck gears, but now I think the gearbox may also be shot, The wheels don't move, but the side rods work just fine...

When I open the gearbox panel on the bottom, I can see easily stop the gear connected to the drive shaft, so the problem is not the drive shaft gear itself, but a gear further in.  The gears that runs the side rods work perfectly, so the problem is after the truck drive and the side rod drive separate.   I can see a couple different gears farther in, so I'm guessing it's one of those ones, but haven't tried to get any of them out yet..

I was looking at NWSL and they offer a gear for the Climax that is not the truck gears, but I'm not sure if that one is the one I need, or how to replace it..

-Stephen

Gear Box

Stephen,

Sounds like the gear inside the gearbox is split that I have shown in the previous posts. Bachman was selling the replacement metal gears but they were out of stock the last time I looked. It might be possible to fix the split gear by reaming out the hole for the shaft, glueing the gear back together and then glueing it back onto the shaft. This problem of plastic gears splitting seems to be caused by the plastic shrinking over time and then the metal shaft puts too much pressure on the gear and it splits. Reaming out the hole till it fits on the shaft should relieve this pressure so that the glue (ACC) might hold it together, of course it will now be loose on the shaft, so you have to glue it to the shaft as well.

Since the alternative is an inoperable locomotive, you haven’t got anything to lose by trying!

Is this the same

Is this the same gear?

https://shop.osorail.com/product.sc?productId=3423&categoryId=-1

-Stephen

Might be the Same

This sounds like it might be the correct gear, but there is no picture. Maybe contact NWSL to see, but you had best do it soon as they are going out of business.

Removal of valve gear drive shaft from valve gear

By removing the hexagonal sided screw from the valve gear, found the gear shaft removal very easy. Replacing the screws requires skill and patience but no parts were broken or stressed.

Valve gear drive shaft

Bachmann used to offer a life time warranty on locomotives.

If they still do, why not contact them to see about sending the inoperable ones back.  They might replace the broken plastic gears with the newest version of metal gears to solve the problem.  

...

If that was an option, Russ, Harry would have likely done it years ago!

That warranty is long past gone, what they have now is a replace with similar product if your broken locomotive is relatively new, they have been long out of the high breakage rate replacement parts or locomotives for the Climaxes, Shays, or any of the other unique locomotives like this.

To top it off, any replacement engine of the same type or replacement part of the same sort will swiftly break in the same manner as the previous one did anyways.  We're truly on our own at this point.

This means, if you love the locomotive, you learn how to fix it yourself, and hopefully find a more robust solution in the process.  One member here found that slipping washers over the axle ends of cracked 44 tonner truck gears will hold them together to the point where they're useable again.  Others have 3D printed the necessary parts.  Either case is a better solution than "just send it back to Bachmann." 

And before you say, "just shove it and buy someone else's locomotive," Good luck with that attitude!!! The only available climaxes are literally the Bachmann option, there is nobody else.  And right now, IF your climax or shay is a running model, it commands $200-$500.  That's a Bachmann On30 model to boot!!  So Harry's documented process and procedures here are a goldmine for anyone looking to flip a couple of these otherwise beautiful models with this Achilles heel.

Valve gear screw partially removed using tweezers

Bogie gears now on the replacement list

Thanks to this post replaced successfully the main drive shaft only to find the middle bogie drive gear split. Front bogie working only but moving or should I say dragging itself on the track. Looking forward to this simple job when parts including spares arrive.

Valve gear removal

Ready for reassembly

Parts waiting reinsertion