I have an older Bachmann HO scale SD45 with the white axle gear on a drive wheel set, that is split and slipping. The Bachmann parts department said they no longer carry that axle gear but perhaps someone here has a gear or a suggestion how to fix the problem. Is it possible the axle gear on a newer model engine could replace the SD45 gear? Any suggestions will be greatly appreciated.
Capt. Brigg Franklin, CEO
Pacific Cascade Railway in HO gauge
www.pacificcascaderailway.com

I have an older Bachmann SD4 that the plastic axle gear on the middle axle has split and now clicks when running the engine. The gear does not look like the 00M02 gears shown on the parts sheet for the DCC model SD45 on the website available parts sheet. Mu gear has a wider sleeve that the metal axles slide into. Where can I find a part number for this older axle gear, where can I find the gear, and how to order it? Thanks for any assistance.
Capt. Brigg Franklin
CEO Pacific Cascade Railway in HO scale.
Capt.brigg@pacificcascaderailway.com

Thank you very much Len.
I'm sure you have helped me avoid at least a half dozen errors working with these unfamiliar engines.  
Do you work for Bachmann? They should pay you.  
My other questions were, should I glue the hand rails on, and where can I get a replacement screw for the coupler box?

Len, once again you came through with some very good ideas and pictures, thanks. Why did you decide to leave the motor lead wires in tact rather than cut them off like in the second description? Also, did you find going directly to the truck pickups with wire better than coming off the frame as he did? Time to take things apart and start learning.  

This was not easy to get a Photobucket account.

Hopefully this shows the frame.

Len, the "light board" looks like the one in the diagram, but the frame on my SD45 is split vertically with at least three screws holding the sides together. The light board also has four little "fingers" holding it on top of the frame. I tried to upload a picture of the frame but it was apparently more than 128 KB in size. I'll try to downsize a picture and try to upload it again. Thanks for your continued interest.

The SD45 should be DCC Ready, with an 8-pin decoder socket. Use a decoder with a short harness, as shown here:

Sorry Len, no decoder socket, just a long insulation strip with lights at each end, pined to the top of the frame. Probably pre-DCC  installed sockets.   But thanks anyway. I will visit the link you posted to see if there are any other instructions.

I recently acquired two Spectrum, EMD SD45 NP  Diesels. I visited the Bachmann booth at the Portland 2015 NMRA train show to learn how to remove the shell from the frame (thanks guys.) I'm now interested in suggestions on the best way to add a DCC decoder (no sound). I have added decoders to some of my Atlas engines and am good at soldering. I'm comfortable that I will eventually figure things out myself, but would appreciate any suggestions to keep me from having to make all the mistakes.  I'm also interested in if I should glue the hand rails onto the body as they keep falling off, and I'm missing the small screw that holds one of the coupler boxes onto the shell. Where can I get a replacement or what size is it?
Thanks for any suggestions. Capt. Brigg CEO, Pacific Cascade Ry. in HO.