Best guess is that you have an early version that does not have drive-line isolation between the trucks. There is a retrofit drive-line available (sometimes) from Bachmann that solves this issue. It has a clutch like slip fitting so that only one of the trucks drives the piston's mechanism and that way the two power trucks are not trying to fight each other.

Can't say for sure that this is your problem, but it sure sounds like it!?!?

If that is in fact your problem, then likely this is the part that you need to replace your rear drive shaft:

https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=69_641&products_id=8300

Thank you for that link Bill, I'll be watching that one closely, but with over five days yet to go and a couple of dedicated Bidiots hard at work on it already, I don't hold out much hope for getting that one!

Still, thanks for alerting me to this listing, I will be watching!!!

Quote from: Loco Bill Canelos on October 15, 2026, 10:47:21 AMI have two and they are great runners. Bill

Thanks for that Bill!

If I can find one and get it at a good enough price, I'm thinking of hacking it up and making it into something like the SPng "Little Giant" #1. It most certainly wouldn't come out as an actual scale model of that engine, but could give a similar general appearance, which would likely be good enough for me!?!?

Thanks Greg, as is soooo often the case, you are the source for need to know info!

I'm a dead rail operator so those brushes are non-issues, should I ever get one of these locos. I was wondering about removing the side-rods and making it look more like a normal diesel however???

Bachmann once made a G-Scale Center Cab Diesel of some sort, with side-rods if I recall correctly?!?!

Does anyone have any info on this model as far as quality of operation and any problems it may have had?

I have been running my Bachmann Climax whose fuel and water tank is packed totally full of electronics, which does have mounts and plug-ins for a fan, on continuous runs for hours at a time, in full sun on days with temps over 100 and no fan without any noticeable problems. Surface temperature on the oil tank top has reached 140 degrees at times, though more typically shows around 120.

Besides draining my batteries faster, I'm not too sure having a fan blowing those kinds of temperatures around the electronics is likely to help much?!?!

It is a small niche market, but in a place like this, it is still fairly strong.

Don't expect to get anything like MSRP original new pricing however!

Heads up guys!

Bachmann is again having a 25% off sale on everything in the web-store it seems. Free shipping too, on orders over $50!!!

Good until September 14th.

My Climax came with the adapter board in the parts bag while the "dummy" board was already plugged into the mother board. My R/C Battery conversion allowed me to leave all of that intact so that all I really had to do was remove the track pickups from the trucks, add on-off switch, fuse, charging jack and then connect my receiver board power to the mother board. Still a tight fit adding yet another circuit board under the oil lid. The batteries, which are 14.4 vdc 4000 mAh and only 1.5 x 1.5 x 2.8 inches are for a robot vacuum cleaner. Only place I could reasonably fit them was standing behind the backhead between the engineer and the fireman. I wrapped them in black electrical tape and now they are practically invisible in that location, yet still easily accessible!

Quote from: Loco Bill Canelos on July 31, 2026, 08:09:40 AMWhen Bachmann manufacturers a locomotive any parts for it are made at the same time, when they run out they run out.

Which all means that folks like Al P. may well have a busy future keeping out little detailed Bachmann treasures alive on into the future!

Quote from: Loco Bill Canelos on July 30, 2026, 08:26:23 AMExcellent, Glad Al was able to help out.  3D printing is definitely mainstream as the way to go for unavailable parts for our older 1:20.3 equipment. 

I can certainly recommend Al P. at the highest level of helpfulness, while his ability to make seemingly any part we may need is unquestionable!!!

Don't like to think of this Climax as being "OLDER" equipment as it is really only six or seven years old. But certainly, as far as the Bachmann parts and service departments are concerned, it is now very obsolete .... sad to say!?!?

Thank YOU, Bill, for recommending Al, and getting me the contact info I needed to proceed down this path. I do believe this will become a very valuable resource for many of us!!!

Ran it 'til the stars came out.

PERFECT!!!

New update, I just received, trimmed out and assembled the 3D printed universal parts that I was needing from Al P. and they seem to be just what the Doctor ordered, or rather, just what my Climax needed! The material these parts were 3D printed from seems quite tough and resilient, maybe even just slightly flexible but not actually rubbery. They took the self-tapping screws well and seem to be visually quite detailed and look very good indeed!!!

As soon as the sun gets lower in the West, I'll get the Climax out on the test oval and get to finally see all the pistons and valves moving along with the engine ...... or so I hope anyway!?!?

Quote from: Greg Elmassian on July 19, 2026, 12:46:33 PMno delrin... never stock on any bachmann.

Where would you find a tidbit like that, I wonder? Good sleuthing in any case!!!

However, even if correct, several formulations of Nylon offer decent lubricity, though few are anywhere near as good as the best Delrin formulas.

There is yet another problem should either of these two materials actually be what those hidden gears are made from. They are both very process sensitive and almost always seriously compromised by the use of regrind, which is quite common in the injection molding world, though always frowned on by the material engineers who specify what things are to get made from! I do believe we have seen these sorts of problems surface rather regularly with Bachmann gears before .... 4-4-0, 2-6-0 & Connie anyone?!?!

Yep, think I'll let it ride for now with the hope that Delrin or similar was used for those gears. If during future lube jobs I find any added resistance to the mechanism there, I'll drill that hole and see about adding a bit of lube. Must be careful though as there are a pair of circuit boards in that transmission housing as well as some paddle like pieces on the crankshaft, all for making the chuff circuit work. Of course, care must also be taken to be sure not to introduce any drill chips, and the hole will have to be big enough to actually provide adequate access yet still be "plugable" with something convenient.

Currently, there is no real concern as those shafts are not turning while I'm running, as I await the replacement driveline universals from Al P. which seem to be coming along rather rapidly, I'm very happy to report!