I have done this for a couple of my DCC service customers.  I used a SoundTrax Tsunami AT-1000 decoder.  While intended as a board replacement decoder for Atlas diesels, it can be adapted for use in the Bachmann GP 40.  The biggest issue is milling the frame weight to make room for the speaker.  I milled the frame above the rear truck to make room for a 16mm by 35mm oval speaker and enclosure.  You have to totally strip the frame first.  Then you need to mill the frame either using a milling machine or band saw.  You can do it with a hack saw, but it it really difficult to do that way unless you can securely clamp the weight in a vice.  You also have to be careful not to disturb the portion of the frame/weight where the rear truck attaches. 

Tom

I have over 150 Shinohara turnouts on my layout.  I've been using Digitrax DCC since 2000.  As long as you have gaps in the rails that lead to the frog and remove the little tiny wipers from the point rail throw bars that make contact under the stock rails they are just as DCC friendly as almost any other turnount.  In my opinion, the Wiring for DCC site goes way overboard on what the author thinks is necessary to make a Shinohara turnount DCC friendly.

Tom

Does this happen on only a single turnout or on all of them?  As has already been suggested, check the gauge of the "offending" wheelset with an NMRA Standards gauge.  If you don't have one of these check gauges, you can get them from Walthers or a well stocked model RR hobby shop.

If it happens on only a single turnout, check that turnout very closely.  At the point where the wheel shorts, you should find one or more "pit" marks where the back of the wheel is touching the back side of the open point rail.  To correct this, I normall take a very small flat bladed screwdriver and place the blade against the pit.  I then push on it slightly to "kink" the rail just a tiny bit.  In essence, to increase the gap fractionally at that point.  You are not looking to make a big bend.  Most often, you only need to increase the clearance by no more than the thickness of a sheet of tablet paper.

Good luck,

Tom

Those are first generation (pre-Tsunami) SoundTraxx sound decoders.  They were top notch for their day (circa 2000).  They are still ok, but not up today's multi channel stereo sound models.

Regards,

Tom

I have no affiliation with either Bachmann or SoundTraxx, but fully agree with Yardmaster's comment that the SoundTraxx decoder offering is superior over MRC.  On my layout, I have two QSI diesel sound decoder locos (not very happy with the prime mover sound), one MRC diesel (not very happy with it at all), and over 40 SoundTraxx Tsunami diesel sound decoders.  I am very, very happy with SoundTraxx.

Tom

I have added sound to several of these locos.  A Micro Tsunami TSU750 will fit across the back of the cab in the same place as the factory BachMann decoder.  The Tsunami is "taller" than the Bachmann decoder, so you will need to carefully paint the visible portions of the purple wrap black to make it less noticeable.

A speaker can be affixed to the cab roof, but first you need to remove the boiler casting that fills most of the cab interior.  You have to carefully cut it away.

As for a speaker itself, I use the mini oval and mini oval enclosure sold by Tony's Train Exchange.  The trick here is to cut off the bottom portion of the enclosure.  You then need to contour the bottom sides/ends of the enclosure to match the curve of the roof.  The roof then becomes the back of the enclosure.  I mounted the speaker enclosure to the roof with a bead of Pacer canopy cement.  (You need to cut off the bottom of the enclosure to lessen its depth so it clears the main drive gear that.)

Do a search of the HO forum postings.  I provided much more detailed instructions here in the past and don't want to bore folks again.

Tom

When I do these kinds of conversions, I generally strip out the PC board from the tender and start from scratch.  Depending on what features I need to add to the loco (for example, cab light, marker lights, firebox flicker light, etc.) beyond the motor and headlight, I use either a TCS 6 wire connector socket/plug set or the 9 wire version offered by SoundTraxx.

In the long run, I find it faster and more straight forward to hardwire the entire unit.  This is especially the case since you have to hardware the loco anyway.  Using the TCS or SoundTraxx harness then provides the quick disconnect between the loco and tender.

Tom

Does anyone know the proper diameter speaker to use in a DCC/Sound ready 3-truck Climax?  A measurement in either inches or mm's will work.

Thanks,

Tom

I suggest you use the Heavy Steam sound set.

Regards,

Tom

Tbd,

I've put sound in two of these.  However, both were kept HO.  I mounted a mini oval speaker to the inside of the cab roof.  I modified the speaker enclosure by cutting off its bottom.  I then sanded the remaining portion of the enclosure so it conformed to the curvature of the roof.  It was then glued in place.  The speaker was inserted in the enclosure as normal.  Unless you are looking into the cab at eye level, you really don't notice it there.

The factory light board is fairly small.  Removing it will gain you maybe 1/8" vertical height clearance.  That's not much room for a speaker.  If you plan on retaining the stock boiler, you'd be better off filling the former light board space with weight.  The loco is extremely light and does not pull well on even the slightest of grades.

Tom

On the prototype, the axle spacing is different between the Alco trucks and the EMD trucks.  I don't recall the exact difference, but I believe the axles are spaced 9" or more furher apart on the Alco truck.  For years, Athearn and some other manufacturers cheated by using the same truck gear box and simply shortened the length of the Alco truck sideframes to fit.  Proto2000 was one of the first brands to correct this condition.  If Bachmann did their Alco trucks correctly, a sideframe swap would not be possible.

However, if you look at the photos available at the Bachmann on-line parts store for the GP30/35 and Baldwin Shark (uses an Alco-style truck), you will see that the truck mounting method for the truck types appears to be the same.  As such, installing the Alco-style truck on the GP30/35 should be possible.  Of course, compatibilty of drive shaft length and truck swing would have to be confirmed (especially if the Alco truck is done with the accurate axle spacing).

Tom

I suggest you go to the TCS decoder web site. 

www.tcsdcc.com

From there, select installation pictures and then go to the section on Bachmann locos.  There you will find images and instructions for installing DCC is almost all of the Bachmann Thomas product line.  It appears that they all must be hard-wire installations, but it is possible.

Good luck,

Tom

PF,

This Tom M. has never worked for Bachmann.  However, I do professional customization work and DCC/Sound installations for folks to fund my "model train addiction."  As such, I've torn down, repaired, and rebuilt dozens of Bachmann steam locomotives.  I'm replacing failed motors in 2 PRR K4 Pacifics at the moment (well at least I will be once the replacement motors from NWSL arrive).

Tom

Quote from: florynow on March 18, 2012, 01:57:56 PM
If Tom M is who I think he is, he is retired from the Bachmann Service department and should know about all there is to know about this.  He always gave me good advice and service while he was there.

I've actually been meaning to ask about how to brighten up 2-8-0 and 4-6-0 headlights for a while and he seems to have answered this.

PF

You have to take care of the trucks first.  Once they are mounted, then and only then, will you know how high the underfame sets from the rails.  At that point, you can determine if you need to use any overset or underset couplers.  Again, my experience has been once you mount the coupler box to the Tyco underframe, a normal shank height and length coupler is all you need.  IMHO, you are better off going with a Kadee metal coupler mounted in a Kadee coupler box (Sorry Bachmann, Kadees have often been imitated, but never duplicated in quality and durability).  I would suggest either a medium/normal length #5 or #148.

Regards,

Tom

I just got done installing a Tsunami TSU1000 in a Bachmann J-class for a friend.  I have a couple of suggestions for improving on Jonathan's fine work.  To mount the speaker, I also purchased the SoundTraxx speaker gaskets.  They are relatively cheap and essentially provide a custom sized circle of doublesided adhesive tape for securing/sealing the speaker to the floor.  Also, I purchased the corresponding SoundTraxx speaker enclosure.  With just some minor filing to the PC board supports adjacent to the speaker mount, the enclosure will fit snugly below the board.  This greatly improves the sound quality to my ear.

Good luck,

Tom