I have a front weight that supposedly came from a
“420” T. I am not familiar with the “420”, but the
weight looks just like the one in the Parts Catalog,
which shows that the “40”, ”420”, and ”430” Tricycle
Tractors use an AM1780T Front Weight and two
M18344T Side Weights. I don’t have the side
weights but the weight that I have has a casting
number of M1854T. I cannot find any reference to
this number in any Parts Catalog, or even at
jdparts.com.Can you possibly shed any light on this?

Yes, we can, although in a round-about sort of way.
First, it has to be realized that John Deere utilized casting
numbers, part numbers, and assembly numbers to identify
parts. Often, but not always, the casting number of a part
will appear in the description of the part. For example, the
casting and part number for a hand-crank Model “G” Flywheel,
F36R, is one and the same. However, current Parts
Catalogs will list the Flywheel as AF245R because it
includes the bolts. In most cases, if more than one part is
included, such as the bolts, it then becomes an assembly,
which is indicated by the two-character prefix beginning
with the letter “A”.

Most JD enthusiasts have heard of, but don’t possess, a
John Deere Master Parts Index, perhaps better known as
the “MPI.” We are fortunate enough to have acquired several
of them over the years, and find the pre-1973 versions
to be the most helpful. Later versions deleted many of the
part, assembly, and casting numbers of the two-cylinder
era. These are huge books, over five inches thick. Original
copies of pre-1973 MPIs in good condition are quite valuable,
but a quality reprint of the 1969 version can be
found on eBay, usually at a reasonable price. An MPI is a
good addition to anyone’s library. It may not be used
often, but it will identify casting numbers that sometimes
Parts Catalogs will not. An MPI will also identify the
model of tractor(s) or implement(s) that a particular part
will fit. For many collectors, an MPI will pay for itself
many times over.

So, utilizing a 1963 MPI, looking up the casting number
M1854T directs the reader to AM1869T, which can be
found in the “40” and “420”/”430” Parts Catalogs. On
page 50-3 in the PC505 Parts Catalog for “420” and
“430” Tractors, Key 10 says that AM1869T consists of
“One AM1780T Front Weight, and One AT15575T
Attaching Hardware.” Since the Front Weight is an assembly
that includes more than one part (most likely the M1647T Hollow Dowels), there’s no doubt that M1854T
is the part number of the weight itself, as other front end
weights for Dubuque-built tractors have the same casting
and part number.

This summer I put one of the factory “live”
hydraulic conversion pumps on my late-styled “A”,
filled it with 30-wt. non-detergent engine oil as recommended,
and all was fine. Later on, I added a 45
Loader, changed the engine oil to 10-wt., and figured
I was ready for winter. Sure enough, as the
first snow fell, the temperatures were down in the
single digits. Even in my unheated garage, the
engine fired right off and I was ready to move some
snow, but I could tell something was wrong with
the hydraulic system. It buzzed and howled to the
point of where I almost shut the tractor off, but I
could see no leaks. The loader would barely lift.
After about 15 minutes, things seemed to get better
and the loader worked fine, getting better the more
I used it. That convinced me the 30-wt. oil was too
“thick” for winter use. Is there something “thinner”
I could use instead?

Well, you did the right thing by using 30-wt. in the
summer, but you quit reading a bit too soon. The Operator’s
Manual says to use the same viscosity oil in the
Powr-Trol system as you do in the engine. Some folks have
reported good all-season performance by using John Deere
Hy-Gard hydraulic fluid the in the hydraulic systems of the
two-cylinder tractors, which is a good idea if you have
newer tractors that use Hy-Gard. That way, if you use a
hydraulic cylinder on your “A”, it won’t contaminate the
oil if the same cylinder is used on a New Generation Tractor
that requires Hy-Gard hydraulic fluid. Regardless of
what decision you make regarding which hydraulic fluid to
use, it’s a good idea to let the tractor and hydraulic system
warm up a bit before using them in cold weather.

I recently purchased a 1939 Model “A” that I plan
to restore. It’s in good condition and has a Power
Lift. However, it has some features I am not familiar
with. There a cast lever instead of the left-hand
pedal for the Power Lift, and there is an aluminum
block sandwiched between the Power Lift housing
and the original cover. The aluminum piece has a