# Bachmann Spectrum 4-4-0 gear problem?



## blakesteam1 (Jan 2, 2012)

I am having a problem with my Bachmann Spectrum 4-4-0, its a painted unlettered olive green & Russia Iron 81392, i was running it yesterday, i hooked up 4 Bachmann ET& WNC passenger cars and when I put power to it, i heard the motor turning but the wheels were not moving, when i unhooked the cars, the loco moved but when it got to the curve it stopped. I got it in February, it ran then, I've followed instructions in how to oil & grease it. The locomotive also free wheels when its on the track, is one of the gears messed up? Do I need to send it back to Bachmann? please help


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## East Broad Top (Dec 29, 2007)

Yep. Main gear is cracked and slipping on the axle. Common with this gear design. If it's still under warranty, you can pack it and ship it back to Bachmann for replacement. You can also order a replacement gear from Northwest Short Line (part #2226-6, if I recall). That's a Delrin gear of a stronger design. Replacing the gear yourself on that loco isn't necessarily difficult, but it's not for the feint of heart, either--especially with the valve gear that's all on the same axle. 

IF the gear is not cracked all the way through, just cracked on the hub to where it slips, you may be able to just glue the gear on the axle with some JB Weld. I did this on my 4-4-0, and it's held up remarkably well over the years. 

Later, 

K


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## blakesteam1 (Jan 2, 2012)

Posted By East Broad Top on 09 Jun 2012 11:12 AM 
Yep. Main gear is cracked and slipping on the axle. Common with this gear design. If it's still under warranty, you can pack it and ship it back to Bachmann for replacement. You can also order a replacement gear from Northwest Short Line (part #2226-6, if I recall). That's a Delrin gear of a stronger design. Replacing the gear yourself on that loco isn't necessarily difficult, but it's not for the feint of heart, either--especially with the valve gear that's all on the same axle. 

IF the gear is not cracked all the way through, just cracked on the hub to where it slips, you may be able to just glue the gear on the axle with some JB Weld. I did this on my 4-4-0, and it's held up remarkably well over the years. 

Later, 

K 
how do I get to the gears? I didn't want to open it up yet until i got advice. i don't know if its cracked or just slipping, it does move when there are no cars.


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## Dansgscale (Jan 9, 2010)

Blake: I replaced the grear on my Specturm 4-4-0 just recently and it was fairly easy to do, the only thing you have to be carefull of is the reversing levers inside the frame. Kevin Strong told me to put some masking tape around then before I disconnected them so they would stay together so when you put them back on they would be in the correct order. 

To start, you would need to turn the locomotive upside down and place it on some foam rubber to cushion it while you dismantle the locomoctive. There is a cover plate on the bottom that is held in place by 8 small screws, remove these screws and place them in a continer so they don't get lost. Next remove the Large Hex screw holding the side rods on to the front driver, this will allow you to remove the side rods from the driver you need to remove to replace the gear. 

With the locomotive turned upside down you can see the reversing linkage I was talking about. Just take a piece of masking tape and wrap it around each of the sets of linkage to hold them together. 

Next use an Hobby knife and pry off the center cap in the middle of the drivers, this will allow acces to the screw to remove the diver from the axle. Don't worry about having to quater them later as the axes have square ends so it is real easy to get them back on correctly. Remove both left and right side drivers and then the reversing linkage can be slid off with ease. you might want to watch these carefullly so you can see how they go together in case the tape comes loose. 

With the linkage off you can pull the gearbox and axle out of the locomotome. there are 6 small screws that hold the gearbox together. 2 on one side and 4 on the other side. After you remove the screws the gearbox will come apart in two pieces and you will be able to remove the axle with the main drive gear. If it cracked completely through you can either try and fix it as Kevin suggested or replace it with one from NWSL (Northwest Shortline) I would suggest counting the teeth on the gear before you order the gear from them. All of the information I have read including what NWSL says on thier website shows this gear as having 24 teeth. However my 4-4-0 have 25 teeth on the drive gear, so I ordered the 25 tooth gear that is listed for the 2-8-0. If yours has 24 teeth then order the one Kevin listed and what NWSL has listed on thier website. 

When I got the gear it did not slide on the axle as the bore hole was to small, so I used a dril bit slightly smalled in diameter then the axle and hand twisted it through the hole to enlarge it. Then taking the axle and gear I used my drill press to push the axle into the gear until it was in the middle of the axle. I did this by drilling a hole in a piece of wood slightly larger than the axle but smaller than the gear, then placed the gear over the hole and then lined the axle up over the hole. With the chuck on the drill press closed all the way down , I then gently pressed the axle into the gear until it was centered over the splines on the axle. 

After that is was just to put it back together in the reverse order that I took it apart. Put the axle and gear back in the gearbox and screw it back together. I would grease the gears first before screwing the gearbox back together though. Then slide the reversing linkage back on to the axle, then putting the drivers back on the axles, followed by the side rods and then the bottom cover plate. 

In all it should not take more than 30 minutes to replace the gear. I had to replace the gear on both my 4-4-0 and 2-6-0 and the procedure works the same on both of them and I have not had any problems with the new Delrin gears. 

Dan S. 
Colorado and Rio Grande Southern 
http://danshobbies.webstarts.com/index.html


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