I need a Yoke Assembly for a g-scale Bachmann Shay.  Anyone have the part for sale? 

https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=69_629&products_id=10027

I have not had good luck replacing the drive trains. Keep getting derailments from the trucks where they worked fine before the gears went bad.  I would gladly pay $50 for a set of new trucks with metal gears.

If I was not clear, the problem started with split bevel gears ... didn't realize this was called a hijack ...

I heard a rumor that Bachmann will be coming out with a new HO Shay with metal gears.  Any truth?

Thanks,
Marty

3 of my 4 Shays are now out of action.  I have bought 3 sets of driveline replacements and they now function mechanically.  However, now I am plagued by derailments that I never had before. I have tried everything.  Now I am having to ... the horror ... replace my Shays with Heislers.  What can I do to save my Shays?

Thanks Dave.  I will get out the magnifying visor and take a look at the universal joints.  I don't have access to my trains today but will let you know when I get a chance if I find anything.

Sid/Wounded Bear,
Glad you have had success with the driveline replacements as it gives me hope.

My latest theory is that it had to be multiple issues, so I was unable to isolate to a single problem.  I agree that any filing, even lightly to take off unseen burrs is a bad idea. I have been able to get one of the Shays to work OK (fingers crossed as I test for a few days) by going back to the untrimmed & unfiled shafts.  Additionally, I found one truck that seemed to have an axle that seemed to be a little off (the shaft sticking past the wheel seemed to be slightly longer than the other axle). The 2nd Shay is hopeless as all I have left are driveline shafts that I filed off the paint on the end.  So, I'm going to by another driveline set and see if I can get the 2nd Shay working.

I will note that I have a 3rd Shay that has been working fine the whole time and I have swapped trucks for testing and it is clear it is the trucks that are the problem and not the Shays.

RAM,
As to derailments, they occur on 18" radius curves over small vertical kinks at track joints, generally under heavy load (4-5 cars on 4-6 percent grades).  So, the idea of the driveline joints binding up (with a partial rotation) as they get close to pulling apart seems likely.

Many valid points.  I still would like to hear from someone that has actually installed the Bachmann replacement drivelines and either has had problems or has not.  I don't think anyone that has posted has installed the driveline parts.

I have installed some of the NWSL gears on one loco years ago, but if I have messed up the trucks somehow in this mess, that will not solve the problem either.

Thanks,
Marty

I remember back when Bachmann sold the complete trucks and had a successful replacement about 5 years ago.  Lousy success with the driveline replacements.

I did take a light file to the male parts to catch any burrs and some of the paint comes off, but it did not help.  Yesterday I took a light file to the female parts.  This may have actually made it worse. As the shafts extend out they may twist and bind under load???


I did check for contact with the coupler pockets.  I checked for bent or uneven brass contacts. I did not keep the truck screw too tight. I tried loosening the screws that hold the side of the trucks together.  I changed the gauge from a little narrow to a little wide.

I'm about ready to give up and retire 2 of my 3 Bachmann Shays, and hope the remaining one does not split any gears. Any other ideas?

 I have 3 Bachmann HO Shays that developed the usual cracked gears in the drivetrain.  That is not the what the question is. I accept that I need to periodically replace the gears.  I thought that buying the replacement driveline sets from Bachmann and replacing the broken ones would be an easy fix. It was easy to do.  However, now I am plagued with front and rear truck derailments.  Has anyone else had this problem?  Any solutions?

The parts I am talking about:

http://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=66_68_92&products_id=1651

Thanks,

Marty

What I am looking for from the Bach Man is any word as to whether there will be any more spare parts in stock - specifically the middle truck assembly.

Thanks,
Marty

As suggested by some of the other posters on trains.com I've tried dabbing the superglue on the shaft and slipping the gear back in position.  I've done it before as well.  Past experience has shown that this may work for a while ... a few minutes or a few weeks ... hard to tell.

NWSL should be able to figure out that this is a huge potential market ... those Bachmann Shays are everywhere ...

My two Bachmann HO Shays are suffering from slipping gears on the sideshafts.  Some of the gears on the sideshaft are sliding out of place when pulling loads on steep grades, resulting in one or more axles dragging instead of turning. You can slide them back, but they work lose again.

Now, I thought I found the solution ... Bachmann sells replacement truck assemblies (front, center, and rear).  You just order what you need and in a few days they arrive and you just pop out the bad truck and put in the new one, hooking back up the drive train ... an easy 1 screw job.

I did find that some of the replacement trucks may have small burrs or something, causing them to bind a bit ... but otherwise things seemed OK.

However, I now see that Bachmann only has the front and year truck assemblies in stock.  They are out of stock on the center truck assemblies and those are the ones that seem to fail the most often.  Are other having this problem and does anyone know if Bachmann is going to get these items back in stock?

Thanks,

Marty