Positraction; Two-Speed Axles; Propeller Shaft Slip Joints; Universal Joints - Chevrolet 10 Series 1970 Service Manual

high speeds, the lubricant should be changed e v e ry 12,000
m ile s . It may be n ecessary to change lubricant m ore
often i f v e h icle is used o ff road in dusty a rea s.

POSITRACTION

Same as standard axle but use only the special P o s i-
traction lubricant.

TWO-SPEED AXLES

The shift unit should be fille d with lubricant to the f i l ­
le r opening on the front c o v e r using re frig e ra tio n m a­
chine o il. The o il le v e l should be checked e v e ry 12,000
m ile s o r 3 months, w hichever occurs fir s t.

PROPELLER SHAFT SLIP JOINTS

P r o p e lle r shaft slip joints should be lubricated every
6,000 m ile s with w ater resistan t E P
which m eets G eneral M otors Specifications #GM 6031M.

UNIVERSAL JOINTS

U n iversa l joints equipped
should be lubricated e v e ry 6,000 m ile s with w ater r e ­
sistant E P chassis g re a se which m eets G eneral M otors
Specification #GM 6031M.
M ore frequent lu brication may be requ ired on heavy
duty " O f f the Road' ' operations.

FOUR WHEEL DRIVE

M ost lu brication recom m endations and proced u res fo r
4 wheel d rive-equ ip p ed trucks a re the same fo r c o r r e ­
sponding components o f conventional d riv e trucks. Only
the front axle, including the d iffere n tia l, the tra n sfer
case, which transm its pow er from the transm ission to
eith e r front o r r e a r axles, and associated linkage points
and a ir vents req u ire special p roced u res.

FRONT AXLE

The front axle should be checked e v e r y 6,000 m iles and
r e fille d with S .A .E . 90 " M u lti-P u rp o se " G ear Lubricant
when n ecessary. With the d iffe re n tia l at operating te m ­
peratu re, f ill to the le v e l o f f ille r plug hole. If d iffe re n ­
tia l is cold, f ill to le v e l o f 1/2" below the f ille r plug
hole. Capacity: 5 pt.
A ir V en t Hose
Check vent hose fo r kinks and p ro p er installation ev e ry
6000 m iles.

TRANSFER CASE

Check the tra n s fe r case le v e l e v e ry 6,000 m iles and, if
n ecessa ry, add lubricant to b ring to the le v e l of the fille r
plug hole. Use SAE " M u lti-pu rp ose"
m eeting requ irem ents o f U.S. Ordinance Spec. M IL - L -
2105B and fo llo w the " G ear Lubricant V is c o s ity T a b le "
fo r p rop er v is c o s ity " M u lti-P u rp o se " gea r lubricant to
be used during veh icle operation.
chassis grea se
with lubrication fittin gs
G ear Lubricant,

CONTROL LEVER A N D LINKAGE

Since no g rea se fitting is provided in the control le v e r
it is n ecessary to brush or spray engine o il on the le v e r
pivot point and on a ll exposed control linkage e v e ry 6,000
m iles .

BRAKES

PARKING BRAKE

E v e ry 6,000 m ile s clean and lu bricate a ll parking brake
p ivot points with w ater resistan t E P chassis gre a s e which
m eets G eneral M otors Specification #GM 6031M.

HYDRAULIC BRAKE SYSTEM

The s e rv ic e brake and parkint brake system s are de­
signed fo r braking p erform an ce under a wide range o f
d riv in g conditions even when the veh icle is loaded to its
full rated veh icle load.
CAUTIO N: D rivin g through
a ffect brake perform an ce.
operation a fte r being
must be dried. T o dry them quickly,
apply the brakes while maintaining a slow fo r ­
ward speed until brake perform an ce returns to
norm al.
The s e r v ic e brakes on veh icles equipped with a split
system a re designed so that in the event o f a hydraulic
fluid leak in on e-h a lf o f the sytem , the other half s till
p rovid es braking action. A brake system warning light
is located in the instrum ent clu ster. The function o f this
light is to indicate a malfunction in the regu la r braking
system . In the event o f broken brake lin es, m a jor brake
fluid loss, a ir in the brake lines or a pressu re deviation
between the front and the re a r wheel brake lin es, the
light w ill com e on and stay on while braking. In this
event, the veh icle should not be driven until the cause has
been determ ined and, i f n ecessary, corre cte d .
V eh icles equipped with power brakes use engine v a c ­
uum to reduce the braking effort.
vacuum re s e r v e which w ill supply two o r m ore power
assisted brake applications a fter the engine has stopped.
A fte r the vacuum r e s e r v e has been exhausted, the veh icle
can s till be stopped by using g rea ter pedal fo rc e .
The C h evrolet braking
ca re; how ever, the system should be checked o ccasion ­
a lly fo r indications o f fluid leak. If leaks a re found the
n ecessary r e p a irs should be made at once.
brakes p ro p e rly adjusted. Check a ll vacuum hose con­
nections fo r leakage.
M aster C ylinder
Check m aster cylin der fluid le v e l in both r e s e r v o ir s
e v e ry 6,000 m iles . If the fluid is low in the r e s e r v o ir ,
it should be fille d to a point about 1/4" fro m the top re a r
o f each r e s e r v o ir with G .M . Supreme No. 11 H ydraulic
Brake Fluid o r equivalent.
Inspection of Brake Lining
CAUTIO N: Brake linings should be p e rio d ic a lly
inspected fo r w ea r.
spection depends upon drivin g conditions such
as tra ffic o r te rra in , and also the d rivin g tech­
niques o f individual custom ers.
LUBRICATION 0-17
deep w ater may
T o assu re norm al
wetted, s e r v ic e brakes
lightly
The system has a
system req u ires v e r y little
Keep the
The frequency o f this in­
CHEVROLET TRUCK SERVICE MANUAL