Lubrication Details; Engine - GMC 1977 motorhome Operating Manual

CAUTION
To help avoid serious damage to your
vehicle, the vehicle should be raised`
only- on twin post hoists of 15,000
pounds or more total rated capacity, at
ENGINE
ENGINE OIL AND FILTER
RECOMMENDATIONS
Use only SE engine oil.
Refer to Maintenance Schedule folder for oil
change and filter replacement intervals .
Operation in a dust storm may require an
immediate oil change.
AC oil filters provide excellent engine protec-
tion.
See your GMC Motorhome dealer for advice
on the frequency of oil and filter changes
under unusual driving conditions.
The recommendations in the Maintenance
Schedule folder apply to the first change as well
as subsequent oil changes . The oil change inter-
val for your vehicle's engine is based on the use
of SE oils and quality oil filters . Oil change in-
tervals longer than those listed will seriously
reduce engine life and may effect GMC Truck &
Coach's obligation under the provisions of the
New Vehicle Warranty .
A high quality SE oil was installed in your
engine at the factory. It is not necessary to
change this factory-installed oil prior to the
recommended normal change period . However,
check the oil level more frequently during the
break-in period since higher oil consumption is
normal until the piston rings become seated.
NOTE: Non-detergent and other low quality
oils are specifically not recommended . Only the
use of SE engine oils and proper oil and filter
change intervals assure you of continued proper
lubrication of your vehicle's engine .
RECOMMENDED SAE VISCOSITY
Single grade oils are preferred, however, mul-
tigrades such as SAE IOW-30 or IOW-40 are
also acceptable.
LUBRICATION DETAILS
7 7
the
suspension- points noted (see dia-
gram) . Before raising, check overhead
clearance to see that it is sufficient for
the vehicle . Do NOT use the vehicle jack
for hoisting or maintenance . It is de-
signed for use
only when
changing
tires.
SAE 5W-20 oils are not recommended for
sustained high speed driving .
SAE 5W-30 oils (if available) may be used
if extreme low temperatures are anticipated.
SUPPLEMENTAL ENGINE
OIL ADDITIVES
The regular use of supplemental additives is
specifically not recommended and will increase
operating costs. However, supplemental addi-
tives are available that can effectively and eco-
nomically solve certain specific problems with-
out causing other difficulties . For example, if
higher detergency is required to reduce varnish
and sludge deposits resulting from some unusual
operational difficulty, a thoroughly tested and
Engine Oil Viscosity Chart