Bachmann HO 3 Truck Shay Bevel gears again

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tbdbitl

New Member
Hello -

I have a Bachmann 3 truck shay with the well documented bevel gear problems. The gears on mine have failed over the last year or so; the posts on this are anywhere from 4 to 10 years old. Obviously, I have done better than many with mine. I have tracked down several of the solutions, but they seem to leave more issues.

1. Replacement trucks from Bachmann - no longer available from Bachmann.
2. Replcement sideframes from Bachmann - also no longer available.
3. Replacement bevel gears - metal ones are available from NWSL. OK - I've been modeling for 40 years - I should be able to handle these.

So I ordered a set of these. The instructions started out good - very detailed, with lots of pictures to help explain what is going on. They get an A+ on the parts but there is a flaw in that the gears must be press fit onto the existing shaft - I believe the size is 3mm. The instructions treat this rather off handed - they suggest pressing the gears on but don't have any suggestions on how to accomplish this in a reasonable manner - but then they do say these parts are not for a beginner. As I said I have been model railroading for 40 years, and have done a fair amount of craftsman modeling, handlaid track and switches, so I don't think of myself as a beginner. (Pride goeth before the fall....)

I went back to the internet to find some secrets about pressing gears onto shaft, and I foound 2 that were relevant. The first was a blog entry that addressed the replacement of the same gears - seemed to be right on target. The person doing the actual repairs is the guy I want to be when I grow up - he slid those gears onto the shafts like it was nothing. The problem was he made a tool specially for the job - replacement jaws for his Panavise, complete with tubes to press things into, and no explanation on how to build one for yourself. The second video was about pressing gears on and off an axle for a traditional steam engine - the presenter used a NWSL Puller to do this. OK - looks more my speed - I'll order up one of those.

I placed the order and had the puller in a couple of days - what a great thing it is to order new tools over the internet. I then tried to use it, and ran into some problems - the puller works well getting gears off, but is not so good at putting gears on. Alignment of the gear on the shaft is not an easy process - you're actually working in 3 dimensions - trying to keep the shaft aligned perpendicular to the gear. I got the gear and axle aligned pretty close, and i heard a pop, and I though I had it, but I had problems keeping the 3mm shaft on the threaded "ram" that works to apply pressure. The gear is on the end of the shaft, but the shaft is not completely through the gear yet, and certainly not to where it needs to be. At this point the shaft began to bend. The first video warned about this - suggesting that your shay is now a doorstop. I directed my attention to the shaft, and seemed to be able to straighten it - it will go through the critical alignment points and turn, but it hasn't been running yet as I don't have the first gear completely on yet.

So, in going back over the posts here and elsewhere - it seems as though unless you're an old school machinist, the prospect of pressing these gears on the old shaft is a major undertaking. What have others done? I did find a reference to another tool from NWSL - The sensipress - but it seems to be not in stock anywhere, and is very expensive ($ 125 if I read correctly,) and also has lots of adapters to fit to what you're doing - each for a small charge.

I should also add that I am somewhat attached to this loco - my grandson thinks it is great, and loves to operate it when he visits. That is incentive enough right there to want it fixed. Additionally, my father worked for the Lima Locomotive works, and while he didn't work on shays, he did help build steam engines.

Can someone suggest what the secrets to pressing tiny bevel gears onto shafts really are? Does anyone have a set of replacmeent trucks for the 80 Ton 3 truck shay that they don't happen to need? Or maybe a set of the truck sideframes with the shafts and gears already in place? Bachmann - are you listening? You have a good running engine here - I have one that includes DCC and Sound, and is in need of replacement parts that are in your catalog online, but not in stock? How about another run of the parts, Pretty please?

Thanks for reading this, and I'd love to hear from others that have dealt with this problem.
 

beiland

Well-Known Member
Excellent posting tbdbitl

Very good explanation of your trials. I look forward to following your final solutions as I have 2 of these locos, as yet unrun.

I might suggest you try posting on several forums, as sometimes expert advice can show up on some and get missed on others at any particular time.
 

GeeTee

Well-Known Member
an axle for a traditional steam engine - the presenter used a NWSL Puller to do this. OK - looks more my speed - I'll order up one of those.

The NWSL puller is used to both pull and press with. It comes with a screw pin for pushing the shaft thru the gear and a hollow screw for pushing gears and a "vee" plate for support. You shouldn't need a press. I used mine for pulling and installing flywheels.
 
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tbdbitl

New Member
The NWSL puller is used to both pull and press with. It comes with a screw pin for pushing the shaft thru the gear and a hollow screw for pushing gears and a "vee" plate for support. You shouldn't need a press. I used mine for pulling and installing flywheels.

Gee Tee - thanks for your response. Maybe this is part of my frustration with the Puller. Mine came with the rectangular frame, two threaded shafts (screw pin?) with a hex socket on one end to accept the allen wrench, and different diameter ends on the opposite end which I assumed were supposed to be equivalent to the axle diameter i was pushing against. (I say that because when I tried to use the device at first, this piece kept sliding off of the end of the axel I was trying to press into the gear. I used some brass tubing that had an inside diameter only slightly bigger (like .002 perhaps) to keep things in line.) I also have the "vee" plate which I have been using as the plate to push against, as the NWSL gears are smaller than the slot on the the side of the rectangular frame. I did not get a hollow screw in the package.

To use the puller, i attached the Vee plate on the side of the frame with some alligator clips, and then mounting this combination into my Panavise. I also have the screw pin that is closest to the shaft size into the threaded receiver in the frame, with the brass tubing helping to hold the shaft in line with screw pin. I then try to adjust the alignment of this so that the hole in the gear is clear in the vee plate, so that when the shaft would not strike the vee plate if it was to slide through the gear as desired.

At this point, I would seem to be ready to press the gear on the shaft, but it does not want to move - the shaft flexes instead.

I thought about puting some light oil on the shaft, but this seemed to be not a good idea - assuming that it allowed me to be successful with the mounting, it might now be slick enough to not be able to maintain the correct position, and would slip out of position. Additionally, all of the videos I have seen do not mention using a lubricant during pressing operations.
 

GeeTee

Well-Known Member
Several things :

1. check the shaft size , standard sizes for HO are 2mm , 2.4mm , 3/32", 1/8" , 3mm , most likely its 2mm or 2.4mm . Metal jaw caliper
2. check the dia of the hole in the gear. It should match shaft size. Best way to do this is with a drill bit .

Make sure there are no burs on the shaft / shaft ends if there are use a small file and or high grit # like 1200 or 000 steel wool to remove , I usually chamfer / taper the end of the shaft to help with starting . Remember Bachmann press theirs in to soft plastic so you'll probably need to do this It doesn't take much just 45 the end the end should have at least this much https://www.ondrivesus.com/includes...p/3db69f9dde9c8ad1f3a09c894b38ddd2.thumb.webp


I usually press the gear onto the shaft using the hollow end screw if you can remove the pin I would use it without the pin (if needed to prevent burring of the gears I insert a piece of wood , corn dog stick , tongue depressor , or even cardboard) ,

As a last resort if the sizes seem correct you may need to dress the inside of the shaft hole with a drill bit to remove a few thousands ...but not much.

If you chamfer the shaft it should go on. Starting is 90% of the battle.
 
Sorry to ask in this thread, but does anyone know who can change the gears to the NWSL metal gears as a service? I have the metal gears already. I'm just afraid of screwing it up and breaking something.
 

jagc1969

Member
I've got two Bachmann-Spectrum 3-truck Shays. Bought them brand new and just when I extracted the locomotives from the foam I saw the bevels falling apart. And this happened for my two Shays. It is a Shame for Bachmann. Or it should be. So , after deep investigations I ended up purchasing a few sets of steel bevels from NWSL . I have seen the same videos you saw and I was very confident as I am not a novice on this business. So I started to press the bevel gear...and I bent the bloody shaft. I wrote NWSL who adviced me to sand the shaft a bit so the bevel gear could enter (really???). Other people told me about using a modeller blowtorch to heat the bevel and when the hole dilates insert the bevel on a previously frozen shaft ... I ended up using a tiny cutting broach to make the hole a little bigger. It worked. Apart from that I had to replace the light bulbs by leds, place a fire-effect led on the firebox, improve current pickups, and I managed to install a Loksound Micro decoder, with a 20 x 40 mm speaker, into the water tender. The bloody thing is working, and I felt very proud of myself, but it was a Hell and I had to do it twice. Hope this helps.
 

Greg@mnrr

Section Hand
Very good explanation of your trials. I look forward to following your final solutions as I have 2 of these locos, as yet unrun.

I also have a Bachmann Shay that has DCC and sound installed and it has been maybe less than one hour of running time and I too worry about the gears failing. Perhaps I should order a set of the brass replacement gears from NWSL.
 

siderod

Member
Hello -

I have a Bachmann 3 truck shay with the well documented bevel gear problems. The gears on mine have failed over the last year or so; the posts on this are anywhere from 4 to 10 years old. Obviously, I have done better than many with mine. I have tracked down several of the solutions, but they seem to leave more issues.

1. Replacement trucks from Bachmann - no longer available from Bachmann.
2. Replcement sideframes from Bachmann - also no longer available.
3. Replacement bevel gears - metal ones are available from NWSL. OK - I've been modeling for 40 years - I should be able to handle these.

So I ordered a set of these. The instructions started out good - very detailed, with lots of pictures to help explain what is going on. They get an A+ on the parts but there is a flaw in that the gears must be press fit onto the existing shaft - I believe the size is 3mm. The instructions treat this rather off handed - they suggest pressing the gears on but don't have any suggestions on how to accomplish this in a reasonable manner - but then they do say these parts are not for a beginner. As I said I have been model railroading for 40 years, and have done a fair amount of craftsman modeling, handlaid track and switches, so I don't think of myself as a beginner. (Pride goeth before the fall....)

I went back to the internet to find some secrets about pressing gears onto shaft, and I foound 2 that were relevant. The first was a blog entry that addressed the replacement of the same gears - seemed to be right on target. The person doing the actual repairs is the guy I want to be when I grow up - he slid those gears onto the shafts like it was nothing. The problem was he made a tool specially for the job - replacement jaws for his Panavise, complete with tubes to press things into, and no explanation on how to build one for yourself. The second video was about pressing gears on and off an axle for a traditional steam engine - the presenter used a NWSL Puller to do this. OK - looks more my speed - I'll order up one of those.

I placed the order and had the puller in a couple of days - what a great thing it is to order new tools over the internet. I then tried to use it, and ran into some problems - the puller works well getting gears off, but is not so good at putting gears on. Alignment of the gear on the shaft is not an easy process - you're actually working in 3 dimensions - trying to keep the shaft aligned perpendicular to the gear. I got the gear and axle aligned pretty close, and i heard a pop, and I though I had it, but I had problems keeping the 3mm shaft on the threaded "ram" that works to apply pressure. The gear is on the end of the shaft, but the shaft is not completely through the gear yet, and certainly not to where it needs to be. At this point the shaft began to bend. The first video warned about this - suggesting that your shay is now a doorstop. I directed my attention to the shaft, and seemed to be able to straighten it - it will go through the critical alignment points and turn, but it hasn't been running yet as I don't have the first gear completely on yet.

So, in going back over the posts here and elsewhere - it seems as though unless you're an old school machinist, the prospect of pressing these gears on the old shaft is a major undertaking. What have others done? I did find a reference to another tool from NWSL - The sensipress - but it seems to be not in stock anywhere, and is very expensive ($ 125 if I read correctly,) and also has lots of adapters to fit to what you're doing - each for a small charge.

I should also add that I am somewhat attached to this loco - my grandson thinks it is great, and loves to operate it when he visits. That is incentive enough right there to want it fixed. Additionally, my father worked for the Lima Locomotive works, and while he didn't work on shays, he did help build steam engines.

Can someone suggest what the secrets to pressing tiny bevel gears onto shafts really are? Does anyone have a set of replacement trucks for the 80 Ton 3 truck shay that they don't happen to need? Or maybe a set of the truck side frames with the shafts and gears already in place? Bachmann - are you listening? You have a good running engine here - I have one that includes DCC and Sound, and is in need of replacement parts that are in your catalog online, but not in stock? How about another run of the parts, Pretty please?

Thanks for reading this, and I'd love to hear from others that have dealt with this problem.

Hello,
We've all been plagued with the bevel gears breaking or disintegrating on both Bachmann Shay's and Climaxes. I have tried a number of "fixes" which all seemed to end in disaster. However, there is one fix that did work for me and I have attached a link (at the bottom). There are a few caveats to this repair however. My 3/8" drill chuck would not go small enough to grip the .Shay's 046" drive shaft so I ended up using a Dremel adjustable chuck and it worked perfectly. Use the slowest setting on your Dremel. I found it doesn't take much to take the knurls down on the shaft. You want still to be able to see and feel the knurls otherwise you risk the chance of the NWSL metal replacement gears not able to grip the shaft tightly. Next, when pounding the shaft onto the metal gear do not pound hard or you will bend the driveshaft. They are made of a soft metal (thanks Bachmann). Use a small (preferably a ball pein) hammer and use repeated soft but firm taps and check your progress. Again, remember to position the replacement gear over the knurled area on the shaft. A mute point but be sure the gears are facing in the proper direction to engage the ring gear mounted on each wheel and both gears must be facing in the same direction.
When removing the journal boxes from the truck side frame (these are what hold the drive shaft to the side frame) there are two small "nubs" on the backside of each journal box. In the link Roger uses a small flat screw driver to pry them off. That didn't work for me as I still ended up breaking the nubs off. That's not to say you wouldn't be successful, I'm just sayin'. An accomplished repair modeller I found gave me directions on how to make an inexpensive tool and fixture from wooden parts and it never fails on removing the journal boxes safely. These journal boxes are extremely important to prevent turning your prized locomotive into a "shelf queen". If your interested in making one of these tool and fixture tools send me a PM or a reply to this thread.
Final thought. These locomotives are a thing of beauty and a marvel to watch operate. Parts for these loco's has dried up so about the only way to repair one is to buy another Shay to be a donor for parts or buy one being sold as salvage at train shows or on eBay. Watch the attached link over and over until you are comfortable in what you are about to embark on.
Good luck!

 

siderod

Member
I also have a Bachmann Shay that has DCC and sound installed and it has been maybe less than one hour of running time and I too worry about the gears failing. Perhaps I should order a set of the brass replacement gears from NWSL.
Greg,

I can't shout loud enough! Get NWSL metal gear replacements for your Shay. Sooner or later the stock plastic gears will start to fail. Having visited with NWSL and, of course, their current supply of these replacement gears will dry up and they may never offer them again. The problem is they have the gears made by an international manufacturer and the cost has risen so much for the blank gear stock that it is cost prohibitive for NWSL to order or stock the gears. Hopefully that scenario will change down the road but who knows for sure.

Jack
 

siderod

Member
Sorry to ask in this thread, but does anyone know who can change the gears to the NWSL metal gears as a service? I have the metal gears already. I'm just afraid of screwing it up and breaking something.
Don't know if you've found him yet or not but the shayfixer.com repairs Bachmann Shay bevel gears with NWSL metal gear replacements. Guys name is Phil and he's a heck of a nice guy.
 

Greg@mnrr

Section Hand
siderod:

I ordered a set of the Bevel Gears from NWSL after reading your advice. Too bad Bachmann doesn't keep a better supply of the gears since the problem surfaced.

Thanks.

Greg
 




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