[Farmall] Super C Transmission work

[Stan Bass]

Anyone have any experience inside the Farmall C or Super C family of
transmissions? I have a Super C that howls/grinds in the upper gears,
more noticeable the higher you go (in 3rd and 4th it's obvious, probably
there in 1st and 2nd also). My 230 does not howl like this at all, so I
assumed it's something I should fix. It's not the clunking or ticking
you get with broken teeth, but a steady sound. I have the deck plate off
now and of course nothing looks obvious, no missing teeth, only thing I
see is the oil slinger gear on the lower shaft does wobble some. If it
matters, the PO did have a belt driven saw on the back of it when I
first saw it; so it probably has some stationary PTO hours. Is it common
to need to replace the bearings on the upper shaft? Just a guess since
that one's not sitting in the oil.

If so, I have the books and need to go hit them next; but I get this
sinking feeling that I need to split the torque tube, axles, and PTO off
to get to all the bearings on those shafts? Is there any chance of this
being done from the top or am I going to need to split this thing in a
million pieces... 
Thanks,
Stan(VA).