Athearn 4 wheel EMD trucks F7 vs. GP-40, and ernst

Model Railroader General Discussion (Model Railroader)
1

I know Athearn lists different part numbers for F7/GP7 trucks and the GP38/40/50/60 trucks, but they seem to me to be the same (in terms of wheelbase, gears, and such). Anyone know definitively? I would like to use ernst regears on the GP38/40/50/60 series, but the (ernst) description does not mention use for these. Has anyone done this successfully?

Thanks-

Mike

2

The trucks are the same mechanically. The only difference is the sideframe castings, which are interchangeable and just press fit onto the basic truck assembly.

3

If your GP uses the Blomberg B, the are the same as the Fs

4

The original F7/GP trucks from the late 60’s and 70’s had outside bearings and metal side frames. The current production(since the GP38-2(sine early 80’s?) have inside bearings and the plastic side frames. The ‘gears’ inside are the same. Swapping in Ernst gears should be no problem

The actual metal wheels(half axles) are different due to the bearing configuration. The current RTR line of 4 axle locomotives use the later setup.

Jim