Gearcase Lubrication - Husqvarna 4421-D Owner's Manual

Gearcase Lubrication

OIL VISCOSITY
Choose the viscosity according to the temperature as shown in the appropriate oil viscosity chart (Figure 27 or
Figure 28). See following NOTE.
NOTE: Use engine oil with API classification SJ for gasoline engines and CF for diesel engines.
Using multi-grade oils (5W-20, 10W-30, and 10W-40) may increase oil consumption. If multi-grade oil is used, check
the oil level more frequently.
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Figure 27 Oil Viscosity Chart – Gasoline Vehicles
GEARCASE LUBRICATION
NOTE: Dispose of used oil according to the environmental laws and regulations for your area.
LUBRICATION LEVEL CHECK FOR FRONT DIFFERENTIAL, TRANSMISSION, AND REAR
DIFFERENTIAL
Each gearcase component is equipped with two oil port plugs (1 and 2) (Figure 29, Figure 30, and Figure 31). When
the vehicle is on a level surface, use the level indicator hole (upper plug) (1) as a lubricant level indicator. Lubricant
level should be even with the bottom of level indicator hole (1).
LUBRICATION CHANGE FOR FRONT DIFFERENTIAL, TRANSMISSION, AND REAR
DIFFERENTIAL
Use the lower plug (2) for drainage (Figure 29, Figure 30, or Figure 31). Remove both plugs to allow the lubricant to
drain faster. See preceding NOTE.
Metal particles may be discovered in the fluid or on the magnetic drain plug when changing the differential or
transmission fluid. These particles are normal and expected for the first few fluid changes. This is a result of the gears
being "net forged", meaning the gears are forged to a shape very close to the final gear size but the teeth are not finish
machined prior to assembly. The "finish machining" occurs when the gears make contact under load during vehicle
operation. The magnetic drain plug is included in the design to collect the metal particles generated from the gear
break in process. This is an established process and is not detrimental to gear service life.
Front differential:
Page 44 2008 HUV 4421 Owner's Manual
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Figure 28 Oil Viscosity Chart – Diesel Vehicles