[Farmall] Another O-12 project, part 2

[sajorgens at sbcglobal.net]

I have a F-12 project I'm ready to sell, when you get caught up - Steve

--- On Sun, 2/15/09, Karl Olmstead <kolmstead4 at msn.com> wrote:

From: Karl Olmstead <kolmstead4 at msn.com>
Subject: [Farmall] Another O-12 project, part 2
To: "Farmall List" <farmall at lists.antique-tractor.com>
Date: Sunday, February 15, 2009, 7:38 PM

Warmed up my shop again today and fixed the 'Billized' O-12 crankshaft
nose.

Had to remove the front motor mount in order to get access to the crankshaft
nose.  I put a floor jack with a 4x4 on top of it under the engine oil pan and
jacked it up slightly, then removed the motor mount.  Took a few pictures of the
mechanical mess that I found.

I measured a couple of good crankshafts in order to determine where I should
cut off the welded extension.  The crankshaft originally ended about 0.8"
in front of the first thread on the crank.  I marked the welded crankshaft, and
cut off the excess with a Sawzall.  I was afraid I'd run into very hard
metal, but it was actually quite soft.  I should have cut forward a bit more;
maybe as much as an eighth of an inch.  I was hoping to just 'kiss' the
original end of the crankshaft, but I actully left about 1/16" of it
attached to the stub I cut off.

Used an angle grinder to clean off the excess weld on the crankshaft nose.  I
could see the setscrew that holds the pin the hand crank engages, and I could
see about half of the outline of the pin on each side of the crankshaft.  Ground
down a screwdriver until it just fit the setscrew slot and was able to get the
screw started.  Lubed it and ran it in and out for a few minutes until it
finally came out.  Tried to drive out the pin that the hand crank engages, but
it was slightly welded into place.  Wound up drilling it out.  Came out nicely,
leaving a clean hole.  Thank goodness Bill hadn't filled up the hole!

Touched up the crankshaft nose with a file and ran a tap through the 5/16"
NC setscrew hole.  Cut off a 1.8" piece of 3/8" drill rod and drove it
through the hole in the crank nose.  Reinstalled and tightened the setscrew.

It's not pretty, but the nose of the crankshaft is back to stock.  I
installed the hand crank assembly temporarily, and it lines up and engages the
crankshaft perfectly.

The front motor mount on the -12 series tractors consists of a cast iron basket
that surrounds the front crank pulley, and a forged steel piece that reaches the
frame rails on each side, into which a sleeve on the cast iron basket slides. 
The basket and the forged piece are usually stuck together.  They certainly are
on this tractor.  I put the motor mount assembly in my sandblast cabinet and
cleaned up the joint between the two parts.  Then I put the assembly on my
workbench and soaked the joint with Kroil.  I'll leave it that way at least
overnight, hoping that Kroil will work its magic.  As I left the shop tonight, I
set the assembly on top of my woodstove, hoping that the residual heat would
speed up the Kroil penetration.

If the penetrating oil doesn't do the job, I'll try heating the outer,
forged part with the rosebud tip on my torch.  Hopefully it'll expand enough
to release the inner, cast basket.  Eventually, if all else fails, I'll cut
the forged part off the cast iron part.  I have many of the forged brackets, but
no spare castings.  They are broken at least 75% of the time, and I ruined one
once trying to pry it out of the forging.

When McCormick-Deering engineers designed the motor mount system, they provided
a way for the frame to twist a bit under loads, without distorting the engine
casting.  The cast iron sleeve inside the forged steel motor mount bracket
seemed like a good idea.  Over time, however, the two parts rust and lock
together.  If the frame then twists under load, the cast iron basket breaks.  So
I need to free up this connection.

I'm feeling a little better about Bill's O-12 tonight.  I've
repaired the worst thing he screwed up.  The rest of the problems are pretty
standard F-12 / O-12 fare.  I will need to rebuild a fuel pump and a magneto;
I've run through my inventory of rebuilt units.

Before too long, I'll have to move the O-12 outside and direct the spray
from my pressure washer into the water jacket opening in the cylinder head. 
Now's the ideal time to flush out some of the rust which tends to plug up
the cooling system.  I'll check the radiator for leaks and probably
dismantle it and reseal it.  The bottom radiator tanks on -12 series tractors
are almost always packed with rust, and frequently rusted through.  Having
rebuilt a radiator a few months back, I know that the work is tedious but not
very difficult.

How far am I away from getting this one running?  Two months, I think.  If I
were in a big hurry, I could probably  do it in a month, but that would require
working in the shop every night after I get home from work.  That's tough,
because it takes about two hours to warm up the shop using my leaky, smokey wood
stove.  Maybe it's time to fire up the propane heater.  If I position it
wisely, I can have my workspace warmed up in fifteen minutes or so, while the
rest of the shop remains cold.

Might be a while before I report in again, depending on progress.  If anyone
would like pictures, please let me know.  My email address is

kolmstead4ATmsn.com, where the AT gets replaced by an '@'.  I can't
get to mail sent to my old olmstead at ridgenet.net account.

-karl
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