OK, 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
www.oakhurstrailroad.com
"Oakhurst Railroad" on Facebook
Have you checked to make sure the shafts can extend and retract freely? Also, do the trucks sit flat and on all 4 wheels if you remove and inspect each one?
I noticed from working on my own Shay that the trucks can be pretty easily overtightened to the chassis, which could keep them from turning and moving properly. I had the gear problem on mine too, but used NWSL's steel replacement gears. Installing them took some work, but the Shay's been working perfect ever since! I just had to be sure everything could move and turn freely so the trucks could all track well.
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Darth,
I will try examining the trucks to see if they are completely level.
The derailments are all on "rough track", mostly vertical kinks, that the locos handled fine before the replacement drivetrains (and my Heislers do fine on). The truck screws are loose enough. However, at other time I have taken a file to the truck center hole to loosen then up even more, especially so they rock better fore and aft.
Another thing that seemed to mess me up was I checked the wheel gauge and thought they were a little narrow so I opened them up a bit, while still keeping them in the range of the NMRA gauge. This didn't help, so I tried putting them back to a little narrow. I have sense tried several different axels and now don't know if this is still a problem. Any experience with gauge issues?
Check the gears themselves and other parts, sometimes a little flash is the problem or with the molding proccess the part can enlarge slightly after many castings so compair the new gears to the old.
I have pretty much tried everything suggested. I was able to get the front trucks on both locos to mostly be OK. The tender trucks I'm still having trouble with. The shaft seems too long and it binds up and derails. Then I clippled the shaft just a bit and it now gets close to coming out and then binds and derails. I have another old tender truck that actually has a burr in the gear that clicks but it is running the best so I'm going with that one for now.
The 2nd loco I gave up with and I disconnnected the drive train to the tender truck and it is mostly OK now, except for the loss of pulling power.
I'm going to stew on it before I make the next step. Maybe buy yet another $30 set of driveline parts?
Are you sure that you got the correct drivelines on the correct truck? If I remember correctly from when I put the NWSL metal gears on my shays, there is an assembly meant for front, rear, and tender specifically.
Hobbez Are you sure that you got the correct drivelines on the correct truck? If I remember correctly from when I put the NWSL metal gears on my shays, there is an assembly meant for front, rear, and tender specifically.
Unlike the Northwest Shortline gears, the Bachmann replacement driveline parts are fully assembled and easy to replace the entire sideframe of the truck as a unit. You don't have to pull off the gears and shafts and universal joints. I have a set of NW Shortline gears and I have used several of them, although it is pretty hard to do.
Something about the driveline set "stiffens" up the rotation and truck swivel motion. After making some of the adjustments mentioned above, I have found that it is under load when the problems mostly occur.
Marty,
I am hoping there is a simple answer to the problem. Have you contacted Bachmann to see what they say??
These shays run perfect out of the box. I would be very disappointed if I had to settle for the type of issues you are talking about here. I have three Spectrum shays and they have only recently developed the cracked gear problem (after 13 years of steady use). I am weighing my options for repairs. Of course this is after I got around to weathering and decaling them... A bit disheartening to hear that there are problems with the truck replacement route.
Good luck,
Guy
see stuff at: the Willoughby Line Site
Are they all identical or are the driveshafts different lengths and maybe you have them on the wrong trucks? Most likely though it is the male and female parts of the shafts not sliding smoothly, the slightest bind here will put pressure on the trucks and keep them from swiveling and rocking easily. Perhaps a very slight sanding of the male parts to remove any burrs or residue will remove just enough material so they slide easily.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I did also post on the Bachmann forum and have gotten a couple of similar suggestions. I think I have tried everything.
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 actually did take a light file to the male parts 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'm about ready to give up and retire 2 of my 3 Bachmann Shays, and hope the remaining one does not split any gears.
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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 done that.
I know the feeling Marty, while I have performed both the Bachmann driveline sides and also the NWSL gears, I'm didn't have any issues with the Bachmann drivelines, but the NWSL gears didn't impress me much. I gave up and decided to invest in a good brass United/PFM Shay, I picked up a used one at a train show for $150.00, it already had the motor upgraded to a sweet Canon motor, and it ran great "as is". Since the motor is already isolated, I just picked up a TCS decoder with built in keep alive and plan on installing it this week. As far as my Bachmanns, they will probably end up on Ebay. The Rivarossi Heisler with sound is another "well built" option for geared steam.
Just my
http://gearedsteam.blogspot.com/2012/06/repairing-bachmann-shay-line-shaft.html
"The true sign of intelligence is not knowledge but imagination."-Albert Einstein
http://gearedsteam.blogspot.com/
Great link Geared Steam. The driveline replacement is easy to do (and now I have tons of practice). I wish I had seen the NWSL gear install video as I busted up several sideframe parts doing the replacement the way of the written instructions. I ended up only replacing 3 gears that way about 5 years ago.
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. 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.
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.
I'll update when I thoroughly test the Shay that seems to be working and when I install a new set of drivelines on the 2nd Shay.
Thanks for the discussion and ideas.