Chevrolet 70 Series 1970, Service Manual

Page: 76 / 841

CAB AND BODY MOUNTINGS 1-45
STEEL TILT CAB
M aintenance inform ation on w indshield w ipers, w indshield and r e a r
window g la ss replacem ent, and cab painting is explained in "GENERAL
MAINTENANCE" sectio n a t beginning of th is group. R efer to LUBRICA­
TION (SEC. 0) fo r cab lu b rica tio n inform ation. Contents of th is section
a r e liste d in Index below:
Subject P ag e No.
D e s c r i p t i o n ............................................................................................. 1-45
Cab Tilting In stru ctio n s .................................................................... 1-46
Cab Mountings ...................................................................................... 1-46
I n s u l a t i o n ................................................................................................. 1-47
S eats ........................................................................................................ 1-47
D o o r s ........................................................................................................ 1-48
Cab V entilation and Heating ............................................................. 1-57
Cab R e p l a c e m e n t ................................................................................... 1-57
T o rsio n B a r R eplacem ent ................................................................ 1-59
T o rsio n B ar Tension A d j u s t m e n t .................................................. 1-60
CAB DESCRIPTION
The s e r ie s 70 through 90 tilt cab is of
a ll-s te e l welded construction (fig. 1). Cab fully s u r ­
rounds engine and can be tilted 55 d egrees to ex­
pose engine for serv icin g . The cab tilting m echan­
ism is in teg ral with cab front mountings and tilting
is accom plished by m eans of a torsio n b a r extend­
ing a c ro s s cab front hinge mountings. One end of
to rs io n b a r is anchored to cab, w hereas opposite
end is anchored to c h a s s is . Cab is re ta in ed in
low ered (operating) position by positive locking
m echanism located at r e a r of cab.
A ccess for m inor engine servicing, such as
oil and engine coolant, is accom plished without
tilting cab through a c c e s s doors in panel at r e a r
of p a sse n g e r s e a t and at top of se a t back r i s e r . A
concealed step is co n stru cted in floor of each door
opening. A lso, a c e n tra l islan d shifting a r e a that is
not d istu rb ed with the cab tilted , is located b e­
tween the s e a ts . Island contains tra n sm issio n shift
le v e r and hand brake le v e r.
Tw o-piece w indshield is retain ed in cab open­
ings with a one-piece ru b b er sea l expanded into
position by a sm all ru b b er in s e rt. No sealing com­
pound o r cem ent is u sed . R e a r window g la s s and
r e a r side g lass is retain ed in sam e m anner as
w indshield glass.
D oors a r e on sw ing-out type hinges w ith the
upper hinge incorporating a spring-loaded door
check for holding door open. Door is re ta in ed at
the r e a r by a s trik e r bolt on cab p illa r. O utside
handles a r e statio n ary -ty p e screw retain ed to door
and have a push button-type latch control.
Vent window in forw ard portion of door is of
frictio n -ty p e having a positive th e ft-re s is ta n t latch.
F rictio n m echanism co n sists of a nylon bushing on
low er pivot of vent which e x e rts frictio n al force
against tension clam p m ounted to door paneling.
Outside a ir en ters cab through a vent directly
in front of d riv e r and through the outside a ir h eat­
ing system . A ir entry from outside of cab is made
through a louvered, rem ovable panel, located in
front ce n te r of cab ju st above ra d ia to r g rille open­
ing. A ir flows through plenum cham ber between
Figure 1 —Tilt Cab Interior Construction
CHEVROLET SERIES 70-90 HEAVY DUTY TRUCK SHOP MANUAL