Split Gears in Bachmann Two-Truck Shay (Fixed! :)

[mlehman]

Hi Everyone,
I am normally a habitue of the MR General Duscussion board, but I sometimes dabble in 1:20.3. I tried searching without luck for the specifics of my problem, but perhaps someone can help me with a little advice.

I have one of the original run of Bachmann 1:20.3 Shays. The last time I ran it was about eight years ago, right after I brought it home new. I lubed it per instructions and stored it properly in climate-controlled conditions.

I finally had a chance to get it out again at our local NMRA division's (http://www.illinoisterminaldivision.org/) Fall Clinic Day yesterday. Power to the Shay brought up the heandlights, etc, but no movement and a clicking noise from the trucks. Disassembly of the trucks showed that three of the four main drive gears had cracked.

I am used to this sometimes happening with plastic gears mounted on metal shafts in smaller scaes. What I want to know is -- Is it worth rehabbing the trucks with new stock gears?

I've heard that Bachmann now has a pair of "Die-Cast Shay Power Trucks with Ball Bearings" (Item #88999) available. Is it a better choice to replace my Shay's old trucks with these?

Will either or both solutions prevent a reoccurrance of the split gear problem?

[kstrong]

The gears on the first generation Bachmann Shays were notorious for splitting. On mine, 3 of the 4 were split. It's still sitting inoperable, mostly because I disassembled it for a future kitbashing project. Bachmann did a "quick fix" for the second run, but it was just that--a quick fix. The "replacement" trucks are a complete redesign and re-engineer. The poor performance of the previous trucks is why they're available as a separate unit--so folks can retrofit their older Shays.

So, go with the replacement trucks, and you shouldn't have any issues.

Later,

K

[two tone]

Depending on where you live Is it possable for you to take the shay to bachmann repair centre? The advantage of this is that you can be sure the job is done correctly. If you do it yourself there is no redress if it fails again.  Remember the old addage once bitten twice shy

[Curmudgeon]

Uh, hang on.

 

ALL Bachmann 2-truck Shays have same motors, wheels, axles, gears, cross-shafts, sideframes (except for one or two hidden differences), end beams, brake beams, etc.

 

The splitting gears is an issue of plastics.

 

You need to carefully check the condition of the housing, top and bottom plate, etc.

Look for housing splits, and screw hole integrity for where the bottom cover attaches.

If yours are 8-screw bottom covers, just replace them, period.

Metal Trucks (check TrainWorld) are a quick fix.

 

Axles with bearings and gears installed are sometimes available from Service, but you need WASHER KITS.

 

If you don't have those, the insulating washers split, screws come loose.....

Washer kits also correct gauge issues.

 

E-mail me.

 

TOC

[mlehman]

I just did a quick and dirty check of things yesterday at the show. They are definitely the 8-screw cover trucks. I didn't see anything else amiss when I checked inside, but it was clear that the gears were the issue.

I've had time to do a little more 'net research and it does sound like conversion to the new metal trucks is the way to go, even if repair parts are available. I presume there is nothing complicated about suhc a conversion. I have have basic wiring and soldering skills and used to do most of the work on my 4x4s, so I think I have the chops to swap out the trucks on this Shay.

Curmudgeon, I dropped you a PM.

[kstrong]

I was under the impression that the new trucks had a more robust drivetrain than the 1st generation Shay trucks, not just a new metal case. Otherwise, I'd expect to still be hearing about split gears. But I'll defer to TOC's knowledge here. He's probably disassembled more Shay trucks than Bachmann's service department.

Later.

K

[mlehman]

I ordered the 88999 truck set Monday morning from St. Aubin Station. The package arrived this afternoon. I am an in-state customer, but the price was right, even with tipping the governor and in comparison to anyone one else who had them in-stock.

I used to work in parts for a Class 8 truck garage. This was pretty much our gold standard for parts service, to have things next day from any supplier near enough that UPS would guarantee one-day service. You gotta keep the big rigs rolling -- and your Shays, too.

It took me about a hour and a half to swap out the original trucks. This involved basic mechanicking skills. The instructions were pretty straighforward, although I considered an upgrade to soldered, heart-shrunk electrical connections to be a good idea.

In testing, at first it was no go.

Then I lifted one truck off the track and got drive immediately from the other truck. OK, I'm a bit dyslexic, even after being careful. I could blame this on the early run wiring, which had two red wires to one truck and two black wires to the other. So I was guessing at polarities, even with being methodical so I didn't screw anything up myself, which is highly likely.

The simple solution to miswiring? Just take one truck loose from the mounting plate, loosen the truck mounting screw, and turn the plate 180 degrees. Do pay attention so that the wires are properly routed so there are no snags in the new position reinstalling the truck. When tested, it ran!

OK, now the headlights are illuminated in the direction opposite to travel.

Takes both trucks loose this time and rotate both 180 degrees.

BTW, be sure you pay attention to the yokes on the U-joints on both trucks when doing all this shuffling around, if you're as clumsy as me, so that driveline stays in synch to avoid binding.

Now we're on the right track. When tested, headlights and direction were synchronized. Success!


I did look at both the original trucks and the replacement, metal frame trucks to compare them. My Shay is from the first run, if it matters. While the trucks are similar in construction, i.e. the same basic design, the new trucks definitely are a product improved version. The main gears that cracked seemed to be the weak point in the original version, although I've heard of other complaints about them. I can only hope that this is a good batch of plastic, but it seems that there are few complaints from those who have made the upgrade, so I'm keeping the fingers crossed that the new versions have paid more attention to alleviating the cracked gears..

However, the new trucks have the gear train arranged on the opposite side of the truck from the originals. This truck also offers a fully enclosed gear box. The original left the top open, so this is a good point for any piece of machinery that will be operated in an outdoor environment. The electrical pickups are substantially more robust. Most other things appear pretty much the same, but having them mounted in a metal frame should help reduce flex and thus excess wear caused by torque loading on bearings and idler shaft ends.

Now to start thinking about batteries, RC, and sound. Hmmm.

[Curmudgeon]

If you'd read the review in GR on those trucks, I know the 180 was specifically mentioned....along with NOT using black tape, but shrink tubing.

[mlehman]

Curmudgeon,
Being a grad student, both my fiscal and time budgets are too strained to be a reader of GR right now. It's been a few years since I pciked up an issue, although I've been tempted several times.


I guess you could say I did my own research on this.


But it's good to know that GR is paying close attention to such issues in their reviews, as that is where they really add value for the reader.

BTW, I dropped you a PM, when you get a chance.

[Curmudgeon]

I don't do those messages, so I had replied and then I saw this and checked. Further down it says don't reply, but go to the link and respond there.

So, I just copied from the sent box and pasted it in.

 

TOC