Kubota GB13 – GB20 maintenance schedule and adjustment values
Kubota GB13 – GB20 maintenance schedule: intervals and adjustment values
The maintenance schedule for the Kubota GB13, GB14, GB15, GB16, GB18 and GB20 comes directly from the original Kubota operator's manuals. Following these intervals keeps your GB series reliable for decades. Below is the complete schedule based on operating hours, plus the official adjustment values for the clutch, brakes and V-belt.
Suitable for the entire series: Kubota GB13 (D9/DA5/N), GB14 (B9), GB15 (B9/S), GB16 (K/FK/H), GB18 (K/FK) and GB20 (K/FK).
Kubota GB maintenance schedule by operating hours
| Part | Action | Interval |
|---|---|---|
| Engine oil | Change | First time after 50 hrs (break-in service), then every 100 hrs or annually |
| Engine oil filter | Replace | First time after 50 hrs, then every 200 hrs |
| Transmission oil | Change | First time after 50 hrs, then every 300 hrs |
| Hydraulic oil filter | Replace | First time after 50 hrs, then every 200 hrs |
| Front axle oil | Change | Every 300 hrs |
| Grease nipples (clutch/brake pedal, lift points) | Grease | Every 50 hrs |
| Starting system, wheel bolts, wiring, battery cables | Check | Every 50 hrs |
| Clutch housing | Drain water | Every 50 hrs |
| Battery fluid | Check | Every 100 hrs (annually if used infrequently) |
| Air filter element | Clean / replace | Clean every 100 hrs · replace annually or after 6 cleanings |
| V-belt | Tension | Every 100 hrs |
| Clutch and brake pedal | Adjust | First time after 50 hrs, then every 100 hrs |
| Toe-in / tie rods, radiator hoses | Check | Every 200 hrs (replace hoses: every 2 years) |
| Fuel filter | Replace | Every 400 hrs |
| Steering gear housing | Check | Every 400 hrs |
| Front differential play | Adjust | Every 600 hrs |
| Valve clearance | Adjust | Every 800 hrs |
| Fuel lines, radiator (flush), coolant, lift cylinder hose | Replace / perform | Every 2 years |
| Fuses (5/10/15 A), lights, bleeding the fuel system | As needed | — |
Note the break-in service: Kubota specifies that engine oil, oil filter, transmission oil and hydraulic filter must be replaced after the first 50 hours and the clutch adjusted. If you've just bought a GB with no maintenance history, treat it as if this service still needs to be done — see also our buying guide for the GB series.
Kubota GB adjustment values (from the operator's manual)
| Adjustment | Value |
|---|---|
| Clutch pedal free play | 15 – 25 mm, measured at the pedal (via the adjustment nut on the clutch rod) |
| Clutch pedal travel | 100 mm (set with the stop bolt) |
| Brake pedal free play | 30 – 40 mm; difference between left/right no more than 5 mm |
| V-belt tension | ± 7 mm deflection under ± 10 kgf finger pressure at the middle of the belt (move the alternator to adjust tension) |
| Tyre pressure | front 1.2 bar · rear 1.6 bar (7-16: 1.8 bar) — see the specifications page |
Why these values matter: an incorrectly adjusted clutch leads to poor disengagement or slipping, causing unnecessary wear on the clutch plate. A V-belt that's too loose causes overheating and poor battery charging — two issues that are often wrongly blamed on the radiator or alternator. And when it comes to the brakes, that maximum 5 mm difference between left and right is not a minor detail: a tractor that brakes unevenly can pull dangerously to one side at higher speeds.
Kubota GB maintenance: practical points to keep in mind
Before every maintenance job, park the tractor on level ground, lower the implement, apply the handbrake, switch off the engine and remove the key. Drain the clutch housing regularly via the drain plug — rain and wash water collect there and are a leading cause of a seized clutch plate. Take used oil to a collection point.
Everything for the service in one go
For the GB15, GB16, GB18 and GB20, the air + fuel + oil filter set (SKU-10050, €34.50) covers the complete filter service. For the GB13/GB14, order the engine oil filter (SKU-002/5) and fuel filter (SKU-150009) separately. The hydraulic filter for the GB16–GB20 (SKU-250003) should be replaced every 200 hours.
