Husqvarna 4421-G/GX/GXL, 4421-D/DX/DXL owner manual Gearcase Lubrication, Front differential

Gearcase Lubrication

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 28 Oil Viscosity Chart – Gasoline Vehicles Figure 29 Oil Viscosity Chart – Diesel 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 30, Figure 31, and Figure 32). 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 30, Figure 31, or Figure 32). 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:

Clean and install the drain plug (2) and washer before filling the front differential with new lubricant (Figure 30). Tighten the drain plug to 108 in-lb (12 N·m). Use a funnel when filling the front differential through the lubricant level indicator hole (1). See Periodic Lubrication Schedule on page 36.Tighten the level indicator plug to 120 in-lb (14 N·m).

Page 44 HUV 4421 Owner’s Manual