I have a Athearn Genesis SD45-2 that has one drive wheel that is in need of replacement. Upon doing a search it comes back with 40" and 42" selections. Does anyone know which one I need? When i checked my included parts diagram it makes no mention of the size only the part number which is 40028. I hope everyone is doing well and thanks in advance for the help!!
-Sam
Samuel Robinson
Lewiston,Maine
I see Athearn part #ATH 40028 shows a 40'' wheel.
Athearn part #ATH 40029 shows a 42" wheel.
That's the best I can do.
Now I am curious, how does one drive wheel need replaced?
A thread here circa 2004 indicated that while the scale diameter of SD45 wheelsets was and is 40", Athearn was then manufacturing engines with 42" wheelsets, apparently for better operation. dharmon said he verified this with a direct response from Athearn.
That may be no help in present practice, of course. Your part number indicates the 40" wheel, which is 'scale' for an SD45. You could always measure with a caliper or micrometer across the treads of the good wheelsets and do a quick scale calculation to be certain.
Id like to know that aswell. The engine was brand new when I purchased it. Id reach out to Athearn but ive had zero luck in the past getting them to reply to me. Thank you for helping me figure this out.
On a Athearn #ATH40028 40'' wheel.
I am not sure how to measure the wheel, as in where to take a measurement but this is what I have.
I took the measurement at the outer edge of the tread, not on the tread back at the flange. What I have is .454". If I lay a HO-Scale ruler from edge to edge (diameter) the closest I can see is 36''+4'', that is 40'' in diameter. We all know the tread is a larger diameter at the flange then at the outer edge.