You might put a micro switch in the frog circuit or use a PECO Accessory switch #PL-13 under the switch if you are using the PL-10 turnout motor.
But BY ALL MEANS go to Allen Gartners web site "Wiring For DCC"  and have a look at that. the address is wiringfordcc.com/switches_peco.htm#a2 and that Will say it all.
I ran into the same problem when I built the "M&TD RR (Me and the Dog RR) everytime I ran a Porter thru the turnout it would die. but you can run them wide open and sometimes they make it but that looks like your playing  with your old tin plate. 
I also have added a small tender behind the 0-4-0 with wheel pickup wires going to the engine and that does the trick real well. As for the 0-4-2, I am playing around with making pickup contacts on the trailing truck but that is a work in progress.
I hope this helps.
Cheers,
Wes aka smokinporter

Ive done this install, but used a MRC "Sound Bug" and it does a good job. The speaker comes with the bug, and installs in the roof. (got to make a small slice in the cab for speaker) mount the sound chip in the front of the motor box.
I know, some will say "but that's a diesel sound"  OK so it is , but with some research I found the gas engine wasn't all that good and when the gas engine got tired and needed to be replaced most owners put in the "Caterpillar" D17000 engine a non supercharged engine. and it worked very well.
If you want the gas engine sound then maybe the "Lok Sound" with the "Galloping Goose" sound, and I believe you can get that chip in a micro-size as well. I have the whole picture spread when I did the install and you are more than welcome to get hold of me so I can email you the file.
I hope that helps and good luck with your quest.
Cheers,
Wes  aka smokinporter

I have heard this for so long. Just turned 70years young sure hope we see them before us older modelers kick off. And that all I have to say about that.
Smokinporter

Hi all,
The older 0-4-0 Porters had a problem when they would even get a quickshort they would take the temper out of the small coil spring on the pickups and the spring would fry. The next ones to hit stateside were designed after the 0-4-2 and use a flat wiper system and they are working fine. I discovered all of this as I started to put DCC and some sound in the first Porters and found out the hard way when you short out DCC you are hitting those small coil spring with a full 2 to 10 amps depending on your system even for a millisecond they will fry. So I have an assortment of defunct 0-4-0 Porters and I use them for parts as I need them.
    Yes I too am waiting for the new 0-4-0 Porters with sound. Have 2 on order and hope I see them soon as I am not getting any younger.
Have Fun, Smokinporter

Hi All
Been On vacation for about a month and just now getting back on line.
Glad to see all the intrest in sound for the side rod.
Ths one is for Amtore,  yes there is a notch in the cab, I put mine in the front about 1/8 "C" channel, fits between the front windows  made  out of styrene, than I put a single chime horn on it, works very well hiding the notch.
Wish I could figure out how to put some pictures here, if I could I would post them. As I think if you all seen them you would have whole fleet of side rods .
I hope this helps for those who want to dive in right away.

Have fun,
Smokinporter

OK John,
Great Job, I always love a project.
First you can  begin by gently pulling the truck off (it is a snap fit be careful of the pickup wiring) the loco and disconect the drive shaft and turn the shaft check for binding if the first truch is ok put it back together. Then go to the next truck and do  the same, if it is ok than you will have to look inside transmission and check those gears.
  The Bachmann Co did a heck of job of planning and building both the "Climax" and the "Shay" as all the gears and shafts really do the work. I hope this helps and I am not out of place by explaining procedure as to how to work on these locos but been there and often wished I could have had some help. But my grandfather always said "if it is already broken you can fix it or forget it as you cannot hurt it" But anyways Good Luck John.

Have fun,
Wes 

Morning,
John 
I suspect as you stated there is a burr, as the gears are injection molded and perhaps do have some flash on the gears, and one would have to use a strong glass or loupe and find the burr and use some assorted needel files and remove the flash. If that scares you contact E-Bay and protest the sale as the buyer has more rights than the seller.
  Also check the axels and look for hair or string rapped around them, as when I got my first "Climax " Loco I found kitty hair in the trucks after running a few hours, as I like the kitty I found it prudent to ban Miss Kitty from the train room, and she is most sad.  I have often thought of putting a couple of pieces of styrene and mounting them on the bottom of the trucks. I hope this helps, and I also hope you get your problem fixed.
Good Luck and have fun,
   Wes  AKA Smokinporter

Hi All,
I did more research on the diesel engine used in the Davenport, it was a Caterpiller D-17000 and even found a sound file.
Have fun,
Wes

Hi All,
Just finished sending info to O-Gauge magizine. but for right now I will try to answer some of your questions.
First off I used the MRC "Sounder" 0001662 sound decoder which has two selectable synchronized diesel prime mover with random associated locomotive sounds. I know the little Davenport was a gas engine when it came out, but as they wore out and needed ovehauled the owners selected to put in diesel truck engines.
Second, this is for Ken, the points that "Tonys" speak of are located on the circuit board on top of the motor. They are two black plastic fasteners that hold the red wire and black wire coming from the wheel wipers, use a pair of small needle point pliers or a 6 inch tweezer and pull the  fasteners place the wires fron the chip according to color code and replace the fasteners.
It is a real easy project to put sound in the "Bachmann" Davenport.


     Have Fun,
    Wes AKA Smokin-Porter

OK
I Will do it.
Have Fun,
Smokinporter

 Hi all I tought some of you would be interested about putting sound in the Davenport.
Check out the MRC Sounder for a great sounding Chip, it is small and easy to put in the Bachmann "Davenport" The chip goes in front of the motor and the speaker goes in the cab mounted to the roof. If anyone is interrested let me know and I will send you some pics.
Have fun,
Smokinporter

Hi  Curt
I believe pin one has a orange wire hooked to pin one on the NMRA Medium socket connector. Pin one is sometimes indicated with a 1, dot, or a triangle symbol. Hope this helps. If you need help, Call
See Ya
Wes Wilson, aka smokinporter

You Might try Precision Scale Co. Inc. They have a catalog about 1 inch thick with O and On parts. I have ordered parts and always had good luck.

Have fun,
Wes aka Smokinporter

Hi Les
You did not say if you wanted info on the Rock Island Lines I will assume you do, so you might try," simpson.edu/ RITS" or go to your search engine and plug in "Rock Island Lines" and a bunch of sites come up.
Cheers and enjoy,
  Wes
PS some years ago I lived in Rock Island

Thanks Tomcat and Mr Bachmann, I will order a new one today.
Regards and keep Smokin,
Wes