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The New
Process 540C
The New
Process 5-speed transmission is a selective synchromesh type with five
speeds forward and one housed in a cast iron case. A 9½" x 2½" band type
parking brake is mounted on the rear of the transmission and standard
S.A.E. six bolt power take-off openings are provided on both sides of
the belly of the case. All gears are helical with the exception of the
first and reverse gear and synchromesh action is provided in second,
third, fourth and fifth gears. The main shaft, countershaft, reverse
idler shaft and all gears are machined from alloy steel and carburized
for durability. In addition, all gear teeth are shot peened for high
fatigue resistance.
The main
drive or clutch gear is supported by a single row ball bearing mounted
in the front of the transmission case. The main shaft is supported at
the front by roller bearings located in the hollow end of the clutch
gear and is supported at the rear by a single row ball bearing located
at the rear of the transmission case. The countershaft is supported in a
single row ball bearing at the front which takes thrust load and by a
roller bearing at the rear. The reverse idler cluster gear rotates on
two steel backed bronze bushings which are a press fit in each end of
the gear.
Pin type
synchronizer assemblies are used. The synchronizer assembly used for
second (2nd) and third (3rd) speeds consists of
two inner synchronizer rings, or cones, and one outer synchronizer ring,
or plate. The synchronizer for fourth (4th) and fifth (5th)
speeds consist of two inner rings, or cones, and two outer rings, or
plates. Shifting is accomplished by a floor mounted gear shift lever
attached directly to the transmission cover.
The image below is a cross
sectional view of the New Process 540C 5-speed manual transmission as
depicted in the 1963 Chevrolet Truck Shop Manual.
Initial Prognosis
When I first purchased the
truck it was more or less fully operational. I say "more or less"
because it did have its fair share of spliced wiring, oil leaks and
other small band-aids to keep it running, but it was in drivable
condition. True, I did experience a problem with the 2-speed rear axle;
however, after rebuilding the Bendix Hydrovac I'm almost certain that that problem was related to
a poor vacuum to the rear axle shifting diaphragm. The New Process 540C
5-speed transmission displayed good shifting characteristics and was
tight even though it is 40 years old. Nevertheless, after removing it
from the truck I could see plenty of
Blue RTV Silicone Gasket Maker
around the output shaft and also the
Chelsea Power
Take-Off assembly. After removing the
transmission cover (#25)
it
appeared that the shifting forks, shafts, gears and everything
else on the inside were in very good shape. Nevertheless, rather than do
a mere cosmetic repair (i.e. clean and paint), I decided to overhaul the
transmission.
Research
The following information
was found on the transmission
case (#44) . This information was part of the actual case casting as
opposed to being on an attached data plate:
NP
12-8-55
C91171
AL
I found myself back on the
web looking for a source that would have an overhaul kit. Finally, I
discovered DT
Components, Drivetrain Products, a company specializing in overhaul
kits for drivetrain components. After navigating the site I came to the
page with the New
Process Heavy Duty Transmission Kits.
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It
is important to know that DT Components does not sell to the direct
public. However, when you enter your state of residence the site
will automatically give you the name of your local customer service
representative, complete with phone number and e-mail address.
I
contacted the customer service representative for Colorado and explained
that I was doing a restoration and needed an overhaul kit for my New
Process 540C; specifically standard kit number TRK-27. I was
subsequently directed to Western Truck Parts in Denver, Colorado, an establishment that sells
to the general public. I gave them a call and they indicated standard
kit number TRK-27 was in stock, so, I took a drive up to Denver and
bought it. The kit contained all new bearings, retainers, seals and
gaskets for a complete overhaul of the transmission.
Preparation
I did not
want to gut and then rebuild the transmission on the floor. Further,
having it on a bench would make it too high to work on comfortably.
Since I fabricated an engine stand I decided to build an adapter that I
could bolt onto the side-mounted PTO opening and then slide into the
engine stand. Using the PTO housing as a template I fabricated a plate
that would bolt onto the case in place of the PTO assembly. Next I
turned down a piece of 1½" cold rolled steel solid round stock to 1.460"
so that it would fit into the engine stand. After achieving the correct
diameter one end was cut at approximately 15º (the approximate angle of
the PTO opening on the bottom of the transmission case) and a hole was
drilled in the opposite end to facilitate a handle. The end with the
handle was drilled and tapped to accept a ½" x 13 bolt to secure the
handle. The shaft was then welded to the adapter plate to finish off the
fabrication. The images below shows the adapter assembly holding the
transmission in the engine stand.
Disassembly
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