I found the Quick Start Guide with the correct CV values! Set CV9 to 12, CV210 to 8, CV212 to 200, CV213 to 8 and CV214 to 8. The instructions say to manually re-program these five CV settings after resetting the decoder to the factory default values. This should solve your problems. My Heisler ran as smooth as silk after these changes.

I had the same problem last year. See my June 10, 2013 message. You are correct, it is some CV settings. The instructions are misleading. The correct settings are on the front of the sound card brochure. I don't recall what they are off hand. I'll look them up and post. I was ready to send my Heisler back to Bachmann too. Hopefully you haven't done so yet.

I installed the sound card in my Heisler after resetting all the CV's to factory defaults as required by the instructions. The sound card worked fine, but the locomotive jittered or vibrated at low speed settings. I tried everything I could think of. I called Bachmann and they said to send the engine to them for repair/replacement.

As I was packing the engine I noticed that there were several CV's listed on the cover page of the quick start guide that had to be manually reset to factory defaults. I reset them to the values listed which were different in some cases than the factory defaults that were listed on the spec sheet and the engine ran fine.

I don't know if I was just unlucky or dumb, but if anyone else has experienced this problem, resetting those odd CV's does the trick. I just wish Bachmann had told me.

Well guys I couldn't wait. I took out the remaining four screws and popped the gear box cover. This exposed the main drive shaft (part 25706 on the diagram). I could turn the rear drive shaft easily. It turned the rear coupling on the main drive shaft without the main drive shaft moving. I took the main drive shaft out with the couplings and the front and rear drive shafts. The front drive shaft was tight. I pulled on main drive shaft and it slid right out of the rear coupling!! The diagram shows a fitting that fits into the coupling and turns it.
I can only conclude that this fitting was still in coupling. There was a fine spline on the shaft to hold the end fitting but the spline didn't fit tight enough to turn the coupling under load. I put a drop of super glue on the spline and shoved it back into the coupling, reassembled the main drive shaft and truck drive shafts, reattached the gear box cover and gave it a try. It worked!!! The rear truck is now powered and the Climax is chugging right up those grades. 
I tried calling the Bachmann service people but couldn't get a technician. I probably will need a new main drive shaft. I'm not sure how long the super glue connection will last.

Again many thanks!

Pete

Thanks guys:

The rear truck is indeed unpowered. I thought at one time it was made this way, but that is not correct. It seems like there is enough contact between the rear drive shaft and the drive gear shaft inside the main gear box, but not enough contact to actually power the rear truck. I have tried to take the gear box cover off to see if I can discover the actual problem. It seems like the main drive shaft may be broken but still in enough contact to turn.

The rear truck works fine. All the gears and drives are in contact and mesh well. So this doesn't seem to be a problem.

I have taken out the four screws on top of the gear box, but the cover won't come off. It looks like I have to take out the screws lower down. I'm not sure what the screws that I have taken out hold. Has anyone taken this gear box apart? I would like to know if I'm getting in over my head.

Thanks again, you guys are great!

Pete 

I have a Climax that I bought about 6 mos. ago. It stalls out on a small grade(1-2%). I checked the drive and everything seems to be connected. However, I noticed that I can turn the wheels on the rear truck and the drive shaft will turn. I can't do this with the front truck. I can lift the rear tuck and the front truck wheels will still turn. If I lift the front truck the rear wheels will not turn. They stall. Any ideas why this loco won't climb grades?