WHEELS AND TIRES

T he tim e o r m ileage intervals for lubrication and m a in te n a n c e services outlined in this section are in te n d e d as a general guide for establishing regular m ain te n a n c e and lubrication periods. Sustained heavy d uty and high speed operatio n or operatio n u n d er adverse conditions may require more freq u en t servicing.

ENGINE

Oil & Filter Recommendations T he letter designation " S E " has been established to c orrespond w ith the req u irem en ts o f G M 6136-M. " S E " e ngine oils will be better quality and perfo rm better th a n those identified with "S A " through " S D " designations and are recom m ended fo r all light-duty gasoline trucks regardless o f model y e a r and previous engine oil q uality recom m endations.

Oil Change Period • Use only SE engine oil. • C hange oil each 4 m onths or 6,000 miles. If more th a n 6,000 miles are driven in a 4-m onth period, change oil each 6,000 miles. • C hange oil each 2 m onths or 3,000 miles, whichever occurs first, u n d er the following conditions: —D riv in g in dusty conditions —T ra ile r pulling or c am p er use. —F re q u e n t long runs at high speeds and high am b ie n t tem peratures. —M otor Hom e use. —Stop and go type service such as delivery trucks, etc. —Extensive idling —S h o rt-trip o p e ra tio n at freezing tem peratures (engine not thoroughly w arm ed-up). • O p eratio n in dust storm s may require an im m ediate oil change. • Replace the oil filter at the first oil change, and every second oil change th e reafter. AC oil filters provide excellent engine protection.

The above recom m endations apply to the first c h ange as well as subsequent oil changes. The oil change interval fo r the engine is based on the use o f SE oils a n d q uality oil filters. Oil change intervals longer th a n those listed above will seriously reduce engine life and may affect the m a n u fa c tu re r’s o b lig atio n u n d er the provisions o f the New Vehicle W arra n ty .

A high q uality SE oil was installed in the engine at the factory. It is not necessary to change this factory-installed oil p rio r to the recom m ended n o rm al change p eriod. However, check the oil level m ore freq u en tly d u rin g the b reak-in period since h ig h e r oil consum ption is norm al until the piston rings become seated. NOTE: N o n -d e te rg e n t and o th e r low quality oils are specifically not recom m ended.

Oil Filter Type and Capacity • Throwaway type, 1 q u a rt U.S. measure, .75 q u a rt

Im perial m easure. • 250 cu. in., 292 cu. in., AC Type PF-25. 350 cu. in. 454 cu. in., AC Type PF-35.

Crankcase Capacity (Does Not Include Filter) • 292 L6 Engine; 5 q u arts U.S. measure, 4.25 quarts Im p erial m easure. • All o th e r engines; 4 quarts U.S. m easure, 3.25 q u a rts Im perial measure.

Recommended Viscosity Select the p ro p e r oil viscosity from the following chart:

RECOMMENDED SAE VISCOSITY NUMBER

10W, 5W-30, 10W-30, 10W-40

- 3 0 - 2 0 0 20 40 60 80 100

TEMPERATURE RANGE ANTICIPATED BEFORE NEXT OIL CHANGE, °F.

N O TE: SAE 5W-20 oils are not recom m ended fo r sustained high-speed driving. SAE 30 oils may be used at te m p eratu res above 40°F. SAE 5W-30 oils are recom m ended fo r all seasons in vehicles norm ally o p e ra te d in C an ad a. The p ro p e r oil viscosity helps assure good cold and hot starting.

Checking Oil Level The engine oil should be m a in ta in e d at p ro p e r level. The best time to check it is b efore o p e ra tin g the engine o r as the last step in a fuel stop. T his will allow the oil accum ulation in the engine to d ra in back in the crankcase. To check the level, rem ove the oil gauge rod (dip stick), wipe it clean and re in se rt it firmly fo r an accurate read in g . T he oil gauge rod is m arked " F U L L " and "A D D O IL ". I f the oil is at o r below the " A D D " m ark on the dipstick, oil should be add ed as necessary. T he oil level should be m ain ta in e d in the safety m argin, n e ith e r going above the " F U L L " line n o r below " A D D O IL " line.

N O TE: The oil gauge rod is also m arked "U se SE E ngine O il" as a re m in d e r to use only SE oils.

Supplemental Engine Oil Additives The reg u lar use o f su pplem ental additives is specifically not recom m ended a n d will increase o p e ra tin g costs. However, supp lem en tal additives are availab le th a t can