Hudson 63 1936, Mechanical Procedure Manual

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MECHANICAL PROCEDURE MANUAL
SECTION 19
Page 7
This same unit is also used on the 1936 Hudson models
under the name "Delco."
The 1937 Hudson models use the Delco type shown in
Figure 1907. These differ from the former type in piston valve
arrangement, incorporating a valve in the bottom of the working
cylinder in place of the flapper valve and constant bleed hole and
require a different procedure for servicing except refilling.
Operation, 1934-1936
In the operation of the 1934-1936 design the valve plate and
disc are lifted from the seat under comparative low pressure on
the compression stroke allowing oil to pass through the piston
into the upper portion of the working cylinder. Since a consider-
able portion of the oil in the working cylinder is displaced by the
piston rod during its downward movement this oil in excess of
that needed to fill the space above the piston is forced out
through the constant bleed hole in the flapper valve at the bottom
and into the reservoir.
On the rebound stroke the oil in the upper working cylinder
is confined until the valve plate (3) is sprung down from the
valve disc (8). The selection of the proper valve plate determines
the point at which the pressure will be relieved and consequently
the spring control afforded by the shock absorber. During the
rebound stroke the flapper valve in the bottom of the working
cylinder is raised off its seat permitting free flow of oil from the
reservoir to the lower working cylinder so that it will be filled
for the next compression stroke.
1937 Delco Shock Absorber Operation
On the compression stroke the valve plate (A), Figure 1907,
is sprung away from the top of the piston (C) when sufficient
pressure is developed to spring the disc and the supporting star
spring (B). This permits oil to flow to the working chamber
above the piston.
The control of the oil, displaced by the movement of the
piston rod into the cylinder, which must return to the reservoir
(D) is by the valve assembly (E). As pressure is built up a
small amount of oil passes through the opening in the center
of the valve stem (F) and out through small grooves milled in
the upper face of the sleeve (G). When the pressure for the
required control is built up it forces the sleeve (G) away from
its seat and the oil flows through the valve to the reservoir.
On the rebound stroke the valve plate (A) covers the out-
side passages in the piston but permits oil to flow through the
inside passages to the rebound valve. A small amount of oil
passes through notches out in the outer edge of the metering
plate (H) to cushion the "take up" of the unit.
When the pressure in the working cylinder reaches a predeter-
mined point it forces the disc (J) down on the retainer (L)
against the pressure of spring (K) allowing oil to pass below
the piston so long as the required pressure is maintained in the
working cylinder.
During the rebound stroke the valve (N) lifts off its seat (E)
to permit oil to return from the reservoir to fill the working
cylinder for the next compression stroke.
Refilling
1. Remove Shock Absorber from car and thoroughly clean
away all dirt around filler plug.
2. Pull out shock absorber to fully extended position.
3. Remove filler plug (P), Figure 1907, and filler plug
gasket.
Figure 1905—Spicer-Delco Valve Parts
Figure 1906—Assembling Valve Parts