Hi, I am aware of a problem that exists with Overland Brass 4-8-4 RF&P HO scale locomotives with the idler gear slipping. I have an RF&P Overland Brass 4-8-4 recently experience this “slipping”. The motor runs but the locomotive will not move. I am aware that NWSL makes a replacement gear box for this unit. Is this the correct fix for this problem? and is the gear box complete assembled or do I need to assemble it myself?
Overland did offer a replacement chassic for that model which had problems. They might actually have a replacement driver with that gear on it. That would be the quick way of fixing it if they have that part.
Replacing the gear set on the driver requires it to be quartered correctly and the process can be hard to get right unless you have the right tools and quartering set. The replacement gear boxes are easy to install but the gear on the alxe is harder for most people.
There are several good repair shops that will do this for you.
CZ
Assembling the gearbox is the easy part. You will have to pull the existing gear and driver off the axle to remove the existing faulty gear. The new gear has to be pressed on the axle and the wheel must be replaced in the same relationship as it was before (quartered). If you have never done this kind of work before it can be intimidating. If OMI has a replacement driver set, it would be relatively easy, but the odds of them having the part are kind of slim. It would be worth a shot to try OMI, Otherwise NWSL is your other option. Sorry.
Yes… NWSL makes a gear case for most everything. Beware that the axle are metric and you need to look for that on their page.
For instructions and options put into Google “Mark Schuster” and you will get to the guru of gear cases and can motor conversions. I met him at a regional convention two years ago… Lot of experience.
see ya
Bob
I was very intrigued by your statement that there are “several good repair shops” that deal with recalcitrant brass engines. Like most brass fans, I"m usually obligated to do my own repair and restoration work but sometimes I come upon an engine that just won’t respond to my TLC. I would appreciate a listing of these repair shops or, failing that, a website or web search keyword that would put me in touch with professional brass repair individuals and/or shops.
I just had another thought for something you might try. If you are not afraid to disassemble the gearbox, remove it from the loco. There is a possibility that the worm or idler gear is slipping on their respective shafts. If this is the problem you can fix it relatively easy. If you can identify that this is happening, the fix is to tighten the fit of the gear or worm to the shaft. Loctite is one solution but the fix I have used most often is to slide the gear/worm off to one side, take a wire nipper type of pliers and make a couple dimples in the shaft right where you want the gear to end up. Doing this will raise some small burrs in the shaft and usually when you slide the gear back over these burrs, there will be just enough friction to hold the gear tightly in place. I’ve remotored and regeared over 60 Locos and have used this technique a number of times. Might be worth a try if you can identify slippage as the problem. Don’t be a gorilla when creating these burrs. Only takes a burr a few thousandths high.
As I was reading through this thread, I was all set to reply with a similar suggestion. [swg]
However, if a gear other than the worm or the axle gear is slipping, it should have no effect on the loco’s performance: as long as the intermediate gears turn, they’ll transmit the power to the next one in line, regardless of whether they’re turning as a unit with their shaft or independent of the shaft. Of course, if they’re spinning on their shaft, they may eventually become misaligned (slip to one side, becoming partially or fully disengaged). Upsetting the shaft as Hergy describes should prevent that.
Most gearboxes, though, don’t have room for much lateral movement of the intermediate gears. If the loco isn’t moving, it’s most likely the axle gear which is slipping, and Hergy’s suggestion should work to cure that, too. I