Bachmann DD40AX UP (Old Stock#81305)

[chuff_n_puff]

Hey Bachman,
I am trying to find out  how smooth a runner was the referenced DD40AX. I understand this special Centennial unit had dual flywheels, which should make it smoother than a flywheeless dual motor unit. I have an old Aethern DD40 flywheeless dual motor unit I converted to DCC with sound and the gears makes about as much noise as the decoder! Will it be worth my time converting this one, or is gear noise just a fact of life with these DD40s?

[Nigel]

......gear noise just a fact of life with ........

Gear noise is due to the modeler not doing a basic well documented tune-up

[chuff_n_puff]

Nigel, Thanks for your reply and that pretty well might be my problem. I custom painted the shell and paid a guy $100 for the converted Aethern DD40. I had to send it back to him when I got it because one of the motors was loose. But anyway, I can get the Bachmann for a song and thought I would convert it to DCC myself. Since it is equipped with flywheels, wouldn't it be a smoother runner than the Aethern? I know I have to isolate and insulate the motors.

[Rich R]

How old is your Athearn?

I've got one that's ancient yet it has dual motors and flywheels on both.
I thought they only made a dual motored or a single motored version. Live and learn I guess.


Cheers,
Rich R

[Nigel]

....Since it is equipped with flywheels, wouldn't it be a smoother runner than the Aethern?......

It depends on the motor(s) and flywheel(s).  A high quality motor without flywheels will be smoother a low quality motor with flywheels.  Early cast Athearn flywheels sometimes made things worse.

[Nigel]

I've got one that's ancient yet it has dual motors and flywheels on both.
I thought they only made a dual motored or a single motored version. Live and learn I guess.

I had a dual motored Athearn DD40 in the early 1980's which did not have flywheels.  At that time, Athearn offered the DD40 with single or dual motors, but no flywheels.

[r0bert]

dually with flywheels

[Jake]

^I'm pretty sure that's a DD35, not a DDA40X a DDA40X had the wide nose, the DD35 had the GP/SD style nose.

[r0bert]

^I'm pretty sure that's a DD35, not a DDA40X a DDA40X had the wide nose, the DD35 had the GP/SD style nose.

Yes, and No,  it's a case of a prototype  that was never built.
Union Pacific did have DD35s both A and B versions, and when they ordered the DD40s they were originally designed to look like the Athearn model represented.
Athearn jumped on board, designed and built the models before the prototype was built.
By the time the DDa40s were actually built, the design had changed into the
Centennial version, the Athearn model was already done, so they just ran with it.
So while it really is a DD40, no prototype was ever built.
The Athearn model can be backdated to a DD35 farly easily, basicly, the fans have to be changed.

[CAB_IV]

also, its DD40AX.

somewhere along the line someone started putting the A in front of the 40, and I don't know why. most books i've seen, and even UP's site lists them as DD40AX

[r0bert]

also, its DD40AX.

somewhere along the line someone started putting the A in front of the 40, and I don't know why. most books i've seen, and even UP's site lists them as DD40AX

sorry to burst your bubble and say you're incorrect, but either way, nearly everyone knows what this monster is.
From EMD own history page

To celebrate its 100th anniversary of the Golden Spike, the Union Pacific takes delivery of EMD's biggest locomotive ever, a 98 foot 8-axle, twin engine DDA40X locomotive rated at 6,600 traction horsepower.

http://www.emdiesels.com/lms/en/company/history/1960/index.htm
UP site list of donated locos
http://www.uprr.com/aboutup/history/loco/locohs04.shtml

EMD DDA40X UP 6946 1984 Portola, CA Feather River Rail Society
EMD DDA40X UP 6944   St. Louis, MO National Museum of Transport
EMD DDA40X UP 6900 1988 Omaha, NE Lauritzen Gardens/Kenefick Park,
Oct. 15, 2005
EMD DDA40X UP 6901 1985 Pocatello, ID   
EMD DDA40X UP 6911 1985 Mexico City, Mexico   
EMD DDA40X UP 6913 1986 Dallas, TX Texas State Fair Grounds
EMD DDA40X UP 6915 1985 Pomona, CA Los Angeles County Fair Grounds
EMD DDA40X UP 6916 1986 Ogden, UT Ogden Union Station Museum
EMD DDA40X UP 6922 1985 North Platte, NE Cody Park
EMD DDA40X UP 6938   North Little Rock, AR Jenks Locomotive Shop
EMD DDA40X UP 6930 1985 Kansas City, MO Moved to the Illinois Railway Museum,
Union, IL.

[Jake]

Okay, thanks r0bert. There's something I never knew!