Chevrolet 1956 Truck Operator's Manual page 46

The . transmission consists of a fluid coupling, which re-
places the conventional clutch, combined with a hydraulically
controlled automatic transmission having four-speeds forward
and one reverse. Gear changing is accomplished automatically
by the transmission in accordance with speed and load de-
mands. See Driving with Hydra-Matic, pages 18-20.
Care and Maintenance. To maintain efficient operation of the
Hydra-Matic Transmission, the fluid level should be checked
every 1,000 miles and the fluid changed every 25,000 miles.
Also an adjustment of the bands should be performed by your
Chevrolet Dealer at the first 1500 mile interval.
Description (Powermatic Transmission). A 6-speed auto-
matic transmission is available as optional equipment on 2
and 2% ton trucks. This is a torque converter type, heavy-
duty transmission with an integl'al, hydraulic brake for re-
tarding truck speed or for continuous downhill braking. Four
planetary gear units provide four ranges (low, intermediate,
high and reverse), and a splitter planetary gear system makes
two gear ratios available in each range.
Selection of the optimum ratio in each range for the
vehicle speed and load demand is automatic. See "Driving
with Powermatic Transmission," page 22.
Care and Maintenance. To maintain efficient operation of the
Powermatic Transmission, the fluid level should be checked
every 1000 miles, the fluid changed every 15,000 miles and
the full-flow oil filter cartridge should be cleaned at each
fluid change.
Propeller Shaft and Universal Joints
Description: The
.V2
ton and the 104" wheelbase Forward Con-
trol models use a tubular propeller shaft in a Hotchkiss drive
system. The universal joints are needle bearing type with a
single lubrication fitting to provide lubrication to all trunnion
bearings through the drilled trunnion.
The
%
ton models use a single propeller shaft Hotchkiss
type drive system similar to
1f2
ton models when equipped with
standard 3-speed or Hydra-Matic transmission and two pro-
peller shafts and three universal joints when equipped with
other transmissions.
The 125" and 137" wheelbase Forward Control models use
two propeller shafts and three universal joints both as stand-
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