LUBRICATION 0 4 able that can be helpful under certain conditions For for sustained high speed driving example if higher detergency is required to reduce SAE 30 and SAE 20W 40 oils may be used at varnish and sludge deposits a thoroughly tested and ap temperatures above 90 F proved concentrate High Detergency Concentrate SAE 5W 30 oils may be used at temperatures is available below 32 F Or engine oil supplement SAE 10W 40 oils may be used at temperatures between 0 and 90 F Engine Oil Chcmge Interval Change engine oil each 4 months If more than 6000 POWERGLIDE TRANSMISSION miles are driven in a 4 month period change oil every Every 6000 miles Check fluid level on dip stick with 6000 miles This interval applies to the initial change as engine idling selector lever in neutral position parking well as subsequent oil changes The oil change interval brake set and transmission at operating temperature lf is based on the use of oils that meet the requirements fluid level is below full mark on dip stick add small indicated in this section under Engine Oil Recommenda amount of automatic transmission fluid Recheck fluid tions If oil is not changed as recommended serious level and again add a small amount of fluid if needed to reductions in engine life will result bring level to full mark DO NOT OVERFILL Certain driving conditions including trailer hauling General Motors DEXRON Automatic Transmission extensive idling and operation in dust storms or on Fluid Part numbers 1050568 1050569 1050570 which dusty roads necessitates more frequent oil changes has been especially formulated and tested for use in your A high quality MS oil meeting General Motors Standard automatic transmission is recommended Other Auto GM 6041 M was installed in the engine at the factory It matic Transmission Fluids identified with the mark is not necessary to change this factory installed oil prior DEXRON are also recommended to the recommended normal change period However the Every 24 000 miles more frequently if vehicle is used oil level should be checked more frequently during the to pull trailers remove fluid from drain plug hole and break in period since somewhat higher oil consumption add approximately two 2 quarts U S measure 1 2 3 is normal until the piston rings become seated quarts Imperial Measure of new fluid Operate trans mission through all shift ranges and recheck fluid level ln many such situations oil change intervals should not as described above exceed 2 months or 3000 miles whichever occurs first A drain plug is provided It is not necessary to remove the pan unless the fluid has a burnt odor or appears Recommended Viscosity dark in color The following chart will serve as a guide in selecting Noiglbflcate Shut lmkage Wlth lubmcant spawned m the proper oil viscosity The proper viscosity helps assure good cold starting by reducing friction and thus increasing cranking speed REAR AXLE Since the rear axle engine compartment dip stick has Anticipated Temperatures been discontinued the lubricant level will have to be Above Freezing 32 F SAE 20w SAE 10W 30 checked at the filler plug Below Freezing and Above 0 F SAE 10W SAE 10W 30 Every 6 000 miles check rear axle lubricant level at Below O F SAE 5W SAE 5w z0 operating temperature Keep lubricant at level of filler plug lf rear axle is low check three or four speed NOTE When changing oil consider the antici transmission lubricant level also Keep filled with SAE pated temperatures for the next 4 months 80 or SAE 80 90 multi purpose gear lubricant meeting SAE 5W and 5W 20 oils are not recommended requirements of U S Ordnance Spec MIL L 2l05B CORVAIR SHOP MANUAL SUPPLEMENT