Old F9 shell on new F7 frame?

[Fenrus]

Recently acquired a Bachmann N 4658 EMD F9 (circa 1975) wondering if anyone knows if the shell from this 40 year old engine will properly fit on a more modern machined Bachmann F7 such as N 63751 EMD F7A (2013) which is DCC equipped.

Thanks.

[ACY]

Most likely it could be modified to fit, these modifications may include milling out parts of the frame or relocation or removal of some internal components.

[Fenrus]

Thanks for the reply Acy. Guess I asked the wrong question though.

So, does anybody know if the old F9 shell from about 1975 is the same size (length, width, internal height clearance) as the newer 2013 F7 shell?
If they are the same, it would save me the effort of trying to retrofit the older frame to accept a decoder and avoiding any milling that might have to be
done. Just looking at an easy out as it were, if they are not the same size, will just mill the old frame sparing me the expense of a newer one.

Thanks again

[Albert in N]

The F-9 shell is longer than the F-7 shell (in Bachmann locos).  The F-9 trainset locomotive was revised in about 1971 and continued until sometime around 2009 (mechanism revised in about 1983).  The F-9 frame measurement is 3 & 5/8 inches long.  The F-7 frame is 3 & 3/8 inches long.  Both frames are 5/8 inches wide.  I currently own a F-9 (from the Highballer train set of around 2009, and a Spectrum F-7 AB unit revised in 2001 (bought mine in 2009).  I removed both body shells and measured only the frames not including the length of the knuckle couplers.  The F-9 body shell will snap onto the F-7 frame, but sticks out both in front and rear since the F-9 frame is a quarter inch longer.  If it is important to repower the old F-9 with a new mechanism, it is OK to pop the old shell onto a newer F-9 1983 to 2009 powered frame.  Of course that would be DC (analog) only.  Otherwise, use a new DCC F-7 powered frame and expect to possibly stretch the couplers (using long shank conversions).  Being an old guy, I remember when Bachmann F-9s in the early to mid 1970s were about the most dependable and powerful N locomotives at that time.  They originally did not have traction tires (which came about in 1983 with the updated motor mechanism).  The Bachmann F-9 is simpler and not as accurate of a scale model as is the F-7 Spectrum.  However both are fun to run and pull well.

[Albert in N]

From reviews, it is my understanding that the body shell and mechanism of the 2001 Bachmann Spectrum F-7 is much the same as is the new Bachmann DCC F-7.  The added DCC decoder is about the only difference.  The body shells look the same, with exception of different railroad colors. 

[Fenrus]

Thanks Albert, that is exactly what I needed to know. Only reason for me getting the old F9 was to replace one that had been given to me back in 1976/77 it had since been lost due to some missing things from a military move. I had tried another manufacturers 'F' unit but it too was about 1/4 inch short in length. Think it would look a little odd with extended couplers as the trucks themselves would be too far in from the front/back of the loco shell as you indicated.

Thanks again, much appreciate the test fitting you did.