Athearn motor drive, shaft transplant???

Model Railroader General Discussion (Model Railroader)
1

I have a GP35 powered and a GP7 unpowered however, I want to take the motor, drive shaft and trucks off the GP35 chasis/frame and put it in the GP7 chasis/frame and make the GP7 powered and the GP35 unpowered. The chasis of the GP7 is about 1/8 of an inch longer.

Is this transplant possibe?

2

Sorry the GP35 chasis is longer and its only longer by 1/16 of an inch, however I measured in both engines the distance from one worm cover/housing to other on the opposite end and the distance is the same on both of engines. So I assume that the drive shaft assembly and motor would fit??

gp_haro

ps. I tried switching shells and there are too many place where the don’t line up

3

It might work. The problem would be if the connector clip and splines don’t fit. It would be difficult to determine how far the spline goes into the coupling on the GP7 or GP35 without disassemling the GP35 and assembling the GP7. However, it appears that they probably use the same spline and coupling. The best way to find out is to try the swap. Athearn sells splines and connector clips, so if they don’t fit, you can probably buy the correct ones. By the way the GP7 and GP35 fuel tanks look different, so if you did swap the shells, the locomotives would look odd.

4

Just switch out the drives. While you have it apart consider changing wheelsets, inspect and debur any flash on trucks regrease w/ Labelle 106, drop of oil on wheeland worm bearings. When pulling motor rock side to side be careful not to damage motor mounts (older rubber can be hard and will break or distort. If mounts are stuborn push up on 4 lugs bottom fuel tank. If you find any drive spline problem use A-line universal drive line parts to correct. When replacing motor make sure bottom bronze clip( similar to top but has tangs) makes contact w/ frame. If you are planing to use DDC this is the time to isolate the motor from the frame. I use to do this even w/ DC when repowering. Kadee #5 or any other metal shank not isolated from the frame can cause erratic slow speed manuvering w/ multiple units. This is not a short but an intermitant connection changing resistance. If you find this happens on other Athearns you can just simply switch #5 for a 30 series med. centerset coupler.