I have several Athearn Blue Box SD40’s that I’m preparing to (or have already) add DCC decoders. I’ve read all the postings about ‘growl’ here and in several other sites, so I took all those steps already. Gears are cleaned, lightly lubed and flash free. Electrical connections are all soldered, so no more clip on the top. Wheels replaced with NS versions, so no more sintered steel. Armature cleaned and lubed. All run pretty good, including the ones already with decoders.
What I’m wondering, in my relentless quest for performance, is whether anybody has replaced the drive shaft and worm gear with the type found in the RTR versions of the SD40? Athearn makes a 1.305" solid dogbone drive shaft (no U Joints) and a Hi Performance worm gear assembly and I was wondering if this works well or I shouldn’t bother or even if it will fit . I would keep the existiing flywheels and motors from the Blue Box locos
BTW, I don’t have any RTR’s in my fleet at the present time, so I can’t ‘part one out’ to try.
The newer driveline uses a hex shaped inside the flywheel mating to a hex on the drive line. Telescoping action is by the driveline moving in and out of the flywheel. I have put a Kato in that size Athearn loco using the Kato motor and drivelines mounted with adhesive putty. Pretty quiet. I think I had to drill out the Kato Ucup to fit over the Athearn worm gear shaft, been a while.
OK, I see. The flywheel end of the driveshaft would be a different shape. Never thought about remotoring though. That may be an idea. Maybe, some time down the road or maybe buy some newer loco’s.
This is a perfect example of why I always consult ‘experts’ before I go off half -a’d.
Len,It can be done and its not a bad job…Its a matter of changing out the couplings on the flywheel and you’ll be good to go…I did that on two of my BB GP40-2s…
You will be surprise how those engines quited down.
As for the gear growl you’ll probably not be able to get rid of that completely. Nearly every six axle Athearn I’ve had was a growler no matter how much work I put into them.
Yeah, I’ve had some that sounded like coffee grinders, but usually most of the sound can be eliminated. Darn shell acts as an amplifier. If I ever hope to have sound in them, I have to make sure the growk is softer than the rumble of the prime mover. Some may never get to that point.
Larry, I’m sorry for being dense, but how did you change out the couplings? I’ve only seen two types of fittings, the standard one with the U Joints and the long, round end with the raised ‘key’ that comes with the unit and the newer hex end ones. Did you replace the entire flywheel?
Len,I replace the BB flywheel with the newer high performance flywheel ATH95000 $8.98…There’s two in the package…These are superior to the BB flywheels and worth the change out…
If you do this project I think you will be pleased with the results.
Now as another thought…You can also use a Atlas/Trainman GP38-2 drive under the Athearn shell just by grinding some of the weight off.
For what its worth and according to the diesel gurus the Athearn shell is the better of the two as far as details-something about the doors,air intakes etc.
Thanks for the info as it’s good to explore options. I have an Athearn BB U33B that I intend to spruce up, mechanically for DCC and externally. I’ve been leaning towards going with a repowering kit from NWSL. Regardless of the route I take, it’s definitely getting DCC-Sound installed.
My friend and forum member, CMarchan, peformed an outstanding upgrade to one of these units. He posted a thread on it just a few years ago: