One popular series zero turn mower in the Kubota stable is the ZD Series mowers. It offers a powerful 26-HP diesel engine and high capacity HST transmission. The machine was constructed for intense workloads and has been approved for road use including an optional kit that permits easy movement between work sites. The transmission system features one hydraulic motor per wheel to assure easy driving. Comfort for the operator is promised due to a flat deck platform that has an ergonomic adjustable seat.
Maintaining the mowers fluids and filters are essential to assure ultimate operation of the ZD Series mowers. This would include:
• Changing Gear Box Oil
• Changing Engine Oil
• Replacing Engine Oil Filter
• Changing Transmission Fluid And Rear Axle Gear Case Oil
• Replacing Transmission Oil Filter Cartridge
• Cleaning Air Cleaner Element
• Grease Points
A regular maintenance schedule can be found in the ZD Series mowers Owners’ Manual. What follows here is a detailed listing on how to change fluids and filters.
- 1. Changing Gearbox Oil
• Take out the drain plug and filter plug.
• Drain oil.
• Re-install drain plug.
• Remove oil level check plug.
• Pour oil up to the oil level check bug hole.
• Re-install check level and filter plugs.
2. Changing Engine Oil
• Remove drain plug
• Drain oil.
• Fill oil to upper groove of the dipstick
3. Replacing Engine Oil Filter
• Remove oil filter.
• Put a small amount of engine oil to the rubber seal of the new filter.
• Tighten filter quickly until it touches the mounting surface.
• Tighten filter an additional ½ turn.
• Be certain to check that oil is not leaking through the seal of the filter.
• Refill oil
When a new filter is installed, engine oil commonly decreases a bit. Change the filter at 50 hours and every 200 hours of use.
4. Changing Transmission Fluid And Rear Axle Gear Case Oil
• Remove drain plug at bottom of transmission case and rear axle case and drain into oil pan.
• Re-install drain plugs.
• Slowly refill transmission fluid
• Run engine for a few minutes, and then turn off and check fluid level.
• Refill as needed.
Run engine at low RPM’s after changing fluid or filter to allow the transmission to lubricate. Fluid in transmission case is used for the hydrostatic drive system, lift and PTO clutch.
5. Replacing Transmission Oil Filter Cartridge
• Take out drain plug at bottom of transmission case and rear axle case and drain into oil pan.
• Re-install drain plugs.
• Remove old filter with filter wrench.
• Lightly tighten the exposed screw when the filter is removed.
• Place a small amount of transmission fluid to the rubber seal of the new filter.
• Tighten filter quickly until it touches the mounting surface.
• Tighten filter an additional ½ turn.
• Ensure that the fluid does not leak through the seal of the filter, and then top off fluid.
When a new filter is installed, the fluid level will commonly drop a bit. Change transmission oil filter cartridge after 50 hours and every and every 400 hours. Two filters are used, one for the hydraulic pump and the second before the HST pumps.
6. Cleaning Air-Cleaner Element
- • Unlatch air cleaner cover to expose the outer element.
• Clean the element with compressed air no more than 30 psi on the inside of the element.
• Re-install element and air cleaner cover.
Replace both inner and outer elements each year.
7. Grease Points 
• Mower driveline universal joints
• Spindle shafts (3)
• Belt tension pulley
• Belt tension pivot.
• Front side anti-scalp roller bracket (60” and 72” decks only)
• Front side anti-scalp roller (60” and 72” decks only)
• King pin
• Center pin (where chassis pivots)
• Front wheels
Motion control lever pivot bushing
• Motion control lever contact position
• Seat adjuster
(Source: Messicks.com)
