Chevrolet 70 1969 Series, Shop Manual

Page: 746 / 913

SECTION 7
TRANSMISSION AND CLUTCH
CONTENTS OF THIS SECTION
O verhaul.........................................................................7-1
Five Speed T ransm ission.....................................7-1
New Process Models 540, 5 4 1 ......................7-1
Clark Model 282, 285 ..................................... 7-16
Clark Models 325V. 3 27 V .............................7-29
Clark Models 385V. 3 8 7 V .............................7-44
Clark Model 4 0 1 V ............................................7-60
Spicer Models 5652. 5 7 5 2 C ................................7-79
Auxiliary T ransm ission............................................7-97
Spicer Model 5831 - B ............................................7-97
Spicer Model 6 0 4 1 ................................................. 7-102
Spicer Model 7 04 1 ................................................. 7-107
Spicer Model 723 l - A ............................................7-114
Long Clutch ( 12 and 13 In ch )................................7-119
Lipe-Rollwav Clutch (13 and 14 Inch D isc). . . 7-124
5-SPEED TRANSMISSIONS
(NEW PROCESS MODELS 540 AND 541)
DESCRIPTION
The New Process Model 540GL, 541GD, and 541GL
5-speed direct drive synchromesh transmissions shown in
Figure 2 are used as standard or optional equipment on
70 and 80 Series vehicles covered by this manual. Figure 1
shows the shift pattern for these transmissions. The trans­
missions are shifted directly by a gearshift lever mounted
on top of the transmission on conventional models or re­
motely controlled on all tilt cab models.
Mainshaft gears, except 1st speed gear, are helical type
and are in constant mesh with mating gears on the coun­
tershaft. First speed gears and reverse idler gears have
straight cut spur type teeth. Two synchronizer mecha­
nisms are employed to affect smooth shifting without gear
clash.
Two openings in transmission case are provided for in­
stallation of power take-off unit.
F ig u re 1— N e w Process 5 - S p e e d Direct D rive
T ra n sm is sio n S h ift Pattern
TRANSMISSION OVERHAUL
GENERAL
Certain precautions should be observed when over­
hauling the transmission. Unless proper care is exercised,
considerable damage may be done to the various compo­
nents of the transmission.
Overhaul of the transmission should not be attempted
where dirt or other foreign materials are present. Before
attempting to disassemble the transmission, the exterior
of the case should be thoroughly cleaned to prevent the
possibility of dirt entering the transmission internal mech­
anism. During overhaul procedures, all parts should be
thoroughly cleaned in cleaning solvent and then air dried.
Wiping cloths or rags should not be used to dry parts as
lint may be deposited on the parts which may cause later
trouble. All parts, except those being actually worked on,
should be kept covered with clean paper.
When assembling the transmission or subassemblies
during overhaul procedures, lubricate each moving part
before part is installed. Use new snap rings, gaskets, and
oil seals when assembling the transmission.
DISASSEMBLY OF TRANSMISSION INTO
SUBASSEMBLIES AND MAJOR COMPO­
NENTS
(Key Numbers in Text Refer to Figure 3 Unless O ther­
wise Specified)
The following procedures cover complete overhaul of
the transmission. The transmission should be overhauled
in sequence described unless only one unit is to be worked
on.
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SH O P M A N U A L