Athearn Automax and 28" wheels

[TrainReign]

I'm looking to put FVM 28" wheels on my Athearn Automax cars. There appear to be two different types of trucks that were delivered by Athearn on these cars. The early releases have what appear to be Atlas 70T RB trucks. The later Athearn releases have what appear to be Athearn 70T RB trucks. I could be wrong about the identification of those trucks, am I?

FVM of course has two different axle sized 28" wheels, .540' and .553.

Does anybody know which axle size to use??

Thanks.

[jagged ben]

For the early releases with the Accumate(Atlas) trucks, the .553 axle is the one you want.  That's what I used on all of mine.

For the Athearn trucks (McHenry couplers, right?), you probably want the .540 axles.   Athearn sells (33") metal wheelsets with .544 axles.  Possibly you could get either the .553 or .540 to work if you bend the trucks outward or inward a bit.  I don't have any from this release.

I'm pretty sure it has been discussed that only a minority of the prototype Automaxes have 28" wheels.  So if it's a problem getting what you want, you should feel fine using 33" wheels.   

[christoph]

Some testing seems to be necessary.
I have also Athearn cars of the first production time (no Auto-Maxxes but others) and although the trucks looked like Atlas, they always had the shorter axle length.
Even if you don't have 28" wheelsets at hand,  for the check of axle lengths wheelsets of any size would probably work, e.g. 3301 and 3302.

[bbussey]

You also could replace the Athearn/McHenry trucks with Atlas trucks, which would allow you to swap in the FVM wheelsets.  The Atlas trucks are available directly from Atlas.

[Robbman]

Just remember that 28" wheels only go on the outside trucks (on the AutoMax's that have them... I can't remember when the switch was... but early AutoMaxes used all 33"s, at some point the switch was made to 28" on the outside)

[TrainReign]

Just remember that 28" wheels only go on the outside trucks (on the AutoMax's that have them... I can't remember when the switch was... but early AutoMaxes used all 33"s, at some point the switch was made to 28" on the outside)

With two different sized wheels, does that mean that the extreme height over the center truck is 2.5" higher than over the end trucks?

About when the switch over occurred, as best as I can tell the BNSF swoosh Automax cars in the 314300's and 314400's range have 28" wheels.

[Hyperion]

With two different sized wheels, does that mean that the extreme height over the center truck is 2.5" higher than over the end trucks?

About when the switch over occurred, as best as I can tell the BNSF swoosh Automax cars in the 314300's and 314400's range have 28" wheels.

According to UMLER, on our Auto-Max's (I checked a few random cars in the 314xxx series) are all equipped with 33s in both the End and Mid positions.

I was actually surprised that UMLER actually called out the wheel sizes for both End and Mid trucks.

It's possible either UMLER isn't updated or the cars I checked happened to not be converted.

EDIT:  Take that back -- checked a couple cars in 3144xx series, and those cars show 28" in the end position and 33"s in the Mid.   Guess that's a differentiation between the two series of cars.  Surprisingly, these cars, despite having smaller wheels, are run a load limit that's 2000lbs higher and tare weight that's 5000lbs higher.  Guess they must have done some additional engineering in the 10 years between build dates between car series and spec differences between an NRLX-leased car and a BNSF-owned car.

[GaryHinshaw]

Good to know.  The only info I can readily access is sketchy at best, so this helps.  Here's an example of a BNSF swoosh with 28" end wheels (and the stencil seems to bear that out):

http://www.railcarphotos.com/PhotoDetails.php?PhotoID=54382

As best I can tell, the interior wheels are still 33", but it's much less clear:

http://www.railcarphotos.com/PhotoDetails.php?PhotoID=54381

The photo notes indicate that these were purchased from AOK, so these would seem to be old sets.  I have yet to see any other examples, outside this series, that have 28" wheels, but I'd be curious if anyone knows of any.

[TrainReign]

The photo notes indicate that these were purchased from AOK, so these would seem to be old sets.  I have yet to see any other examples, outside this series, that have 28" wheels, but I'd be curious if anyone knows of any.

Interesting that these BNSF cars came from AOK.

Anybody have any pictures of the AOK cars with 28" wheels? or were these 28" wheels put on by BNSF?

[GaryHinshaw]

The BNSF photo I linked to said the car was ex-AOK 502291.  Here is a shot of AOK 502290 with 28" wheels:

http://www.railcarphotos.com/PhotoDetails.php?PhotoID=35517

so it appears they were delivered that way.  I'm not sure what the deal is with these AOK/BNSF cars; here is a shot of a car in the same series wth AOK marks and a BNSF logo (and 28" end wheels):

http://www.railcarphotos.com/PhotoDetails.php?PhotoID=39696

Is AOK a business unit of BNSF?

[jagged ben]

Is AOK a business unit of BNSF?

I'm pretty sure they are not.    Kind of odd to see that on a car.

[Philip H]

AOK is the Arkansas and Oklahoma.

http://www.aokrr.com

edit: fixed URL tag -gfh

[GaryHinshaw]

Right.  This car made me wonder, but I couldn't find any connection in my brief search.