[AT] Super M generator belt / tensioning bracket

[Dean Vinson]

Hmmm.  Last year I bought a 1953 Super M that had been restored several
years ago but is still in near flawless shape.  Given the obvious attention
to detail in most areas, two things seemed odd to me:  it had an old and
rather ragged fan belt on it, and the generator tensioning bracket was
missing.  (Tension on the generator belt was maintained just by tightening
the mounting bolts at the bottom of the generator, around which the
generator can pivot if the bolts are loose, since the adjustable bracket
that normally mounts at the top of the generator just wasn't there).

Last fall I replaced the fan belt, and replaced the generator belt at the
same time.  The old generator belt looked fine but I figured as long as I
was going to the trouble of replacing the fan belt I'd do them both on
general principle.  Both new belts came from OEM Tractor Parts.

I finally got around to looking for a tensioning bracket and found one on
eBay a while ago, and today went to put it on.  It's inexplicably too short:
Even in the "all the way out" adjusted position, the generator is so far in
toward the engine that the belt just hangs loosely draped over the pulley.

The tensioning bracket was advertised as being from a Farmall M and came
with the bracket that actually mounts the generator to the tractor.  Neither
one has any sign of a part number on it, but the mounting bracket is exactly
the same size as the mounting bracket on my tractor so it seems likely that
they were indeed from an M.  The M and Super M parts books confirm that the
generator brackets were the same for both tractors.

The generator belt is marked "04710 Made in Mexico" and "756962".  Neither
of those is the Farmall part number, and a Google search didn't tell me
anything about them.

So the question is, how can that bracket be too short?  Either it's the
wrong bracket (perhaps from an H?), or the belt is too long. 

Or, hmmm, the pulley could be smaller than normal?  The tractor's been
converted to 12 volt... could the restorer have put a small pulley on there
to spin the generator faster as part of that conversion?  It doesn't look
unusually small--I just went back out and measured, and the front face of
the pulley is an even 4" in diameter.  If it's not original, it doesn't seem
like it could be so much smaller than original that it would create all that
slack in the belt.  So, back to the bracket being too short or the belt
being too long... neither of which seems terribly likely.  Any thoughts?

Dean Vinson
Dayton, Ohio
www.vinsonfarm.net