[AT] [Farmall] Super M Fan Belt -- and other fun stuff

[Dean Vinson]

Well, as fate would have it, the Super M I acquired in May happened to need
a new fan belt, just as we'd discussed in these old emails from last April.
Seemed unusual to me since everything else on the tractor looks about like
new, but the inside of the belt was noticeably frayed and ragged looking so
I'd gotten a new one from OEM Tractor Parts.  This afternoon I set out to
put it on, remembering the procedure Mike had mentioned.  I didn't notice
the jam nut around the set screw at first and so wasted a bunch of time
trying to turn that screw with just a screwdriver, which I couldn't get
seated straight because of the angle and interference from the fan blade.
In frustration I thought "the heck with it, I'll skip loosening that sheave
and do it like I'd done on the M a few years ago, just slip a screwdriver
under the belt and rotate the thing off."

I'll be darned if I know how I managed it before.  After an hour of
wrestling and pulling and swearing and losing skin and trying from left,
right, high, and low, I'm here to tell you changing the belt without
loosening that sheave falls into the category of "ain't happening."  I never
even got close.  Finally took a break, washed my hands, calmed down, and
went back to the set screw.  Saw the jam nut, loosened it with a 9/16" box
wrench, easily turned the set screw out, loosened the sheave, changed the
belt and adjusted the tension.  Still took some wrestling and patience but
at least I could see progress.  I changed the generator belt also, as long
as I had the fan belt off, so I expect not to need to try this again.  And
for the life of me I can't figure how I made it work on that M without
loosening the sheave.  Getting the old belt off, maybe.  Getting the new one
on, just not happening.

Anyway, it was fun to get honest dirty and get some hands-on time with the
tractor.  I found and greased all the grease fittings while waiting for
penetrating oil to deal with that set screw, so that little chore is done.
The nice surprise was the hand-starting crank bearing, which was free and
pretty smooth even before I greased it--on my two previous M-series tractors
that bearing was rusted in place.  This tractor has been converted to 12
volts and starts on the first turn and I don't have a manual crank anyway,
but it's nice to know the thing would work.

The other surprise was the compression--I'd taken the spark plugs out to
make it easy to turn the engine over to get that fan belt on, so as long as
they were out I got out the compression tester.  On my '50 M the four
cylinders had tested at 115, 118, 90, and 105 psi, which as I recall folks
here on the list had said was okay for an old light-use tractor.  This SM is
in a lot better shape so I was expecting higher numbers, but not what the
tester showed:  180 psi, 175, 178, and 175.  High-altitude pistons?  What's
a normal range for an SM?


Dean Vinson
Dayton, Ohio
www.vinsonfarm.net


> -----Original Message-----
> From: farmall-bounces at lists.antique-tractor.com
> [mailto:farmall-bounces at lists.antique-tractor.com] On Behalf Of RICHARD
POPE
> Sent: Wednesday, April 21, 2010 10:22 PM
> To: Farmall/IHC mailing list
> Subject: Re: [Farmall] Super M Fan Belt
> 
> Mike & Dean:
> 
> I got the old fan belt off this afternoon, but it wasn't a quick job.  The
> threads on that fan pulley sheave were so clogged with almost 60 years of
> grease and rust that the thing wouldn't turn.  Used lots of penetrating
oil
> and then chased the treads with a small screwdriver.  Got the belt off and
> left some of my DNA on the fan blades, but that's normal.
> Many thanks for your help!
> Richard Pope
> Apple Valley, CA
> 
> 
> ----- Original Message ----- 
> From: "Mike Sloane" <mikesloane at verizon.net>
> To: "Farmall/IHC mailing list" <farmall at lists.antique-tractor.com>
> Sent: Wednesday, April 21, 2010 3:57 AM
> Subject: Re: [Farmall] Super M Fan Belt
> 
>> Dean's procedure will work, but it won't get your new belt tension set 
>> correctly - you need to undo the set screw on the fan pulley and turn 
>> half the sheave in or out to adjust the tension. A flat bar and a small 
>> hammer might be needed to get things moving in the right direction 
>> (there are raised lumps on the pulley hub for that purpose, but it 
>> doesn't/shouldn't take a lot of brute force; a little penetrating oil 
>> will help to make things easier). It helps to have a copy of the 
>> operator manual for an illustration.
>> 
>> If you spread the sheave out first, you can pull the belt off the 
>> crankshaft pulley relatively easily and not bother with removing the 
>> plugs, etc. You will likely skin at least one knuckle on the radiator 
>> fins, but that seems to be about normal for me.
>> 
>> Mike
>> 
>> dean at vinsonfarm.net wrote:
>>> Hi Richard.  Here's how I've done it:
>>>  
>>> Take the plugs out to release compression (and avoid ignition), put the
> tractor
>>> in neutral, set the brakes.  Take the belt off the generator pulley to
> get it
>>> out of your way.
>>>  
>>> Tilt a screwdriver or something between the fan belt and the fan pulley
> and
>>> rotate the fan by hand until the belt rides up and over the edge of the
> pulley
>>> and onto the smaller-diameter neck closer to the fan itself.  That
should
> give
>>> you enough slack to pull the bottom of the belt off of the engine
pulley.
>>>  
>>> Once the belt is only around the fan itself, you can work it past the
fan
> blades
>>> one at a time.  On my M there's a good place to do that down low on the
> right
>>> side, above the lower radiator hose--there's enough room between the fan
> shroud
>>> and the edges of the fan to get the belt past.
>>>  
>>> Putting the new one on is just the reverse.  It's been a couple years
> since I
>>> did this but it worked fine for me.  Hope it turns out to be of some use
> for you
>>> too!
>>>  
>>> Dean Vinson
>>> Dayton, Ohio
>>> www.vinsonfarm.net