Quick answer:
The Kubota M135GX tractor tire size is front 420/70R24 and rear 520/70R38. Other tire setup data found for this model includes Front 14.9R24, Rear 18.4R38; Front 18.4R38, Rear 14.9R24, so confirm the wheel option before ordering.
Front tire420/70R24
Rear tire520/70R38
Front/rear setupDifferent front and rear tire sizes
Tire pressure22 PSI, 20 PSI
Rim diameter24 in front, 38 in rear
Ballast35 gal
Other setup foundFront 14.9R24, Rear 18.4R38; Front 18.4R38, Rear 14.9R24
Kubota M135GX Tire Size Details
| Front tire size | 420/70R24 |
|---|---|
| Rear tire size | 520/70R38 |
| Front/rear setup | Different front and rear tire sizes |
| Other tire setup found | Front 14.9R24, Rear 18.4R38 |
| R1 ag tire size | Front 18.4R38, Rear 14.9R24 |
| Front tire construction | Metric radial |
| Rear tire construction | Metric radial |
| Front section width | 420 mm |
| Rear section width | 520 mm |
| Front aspect ratio | 70% |
| Rear aspect ratio | 70% |
| Front rim diameter | 24 in |
| Rear rim diameter | 38 in |
| Approx front overall diameter | about 47.1 in |
| Approx rear overall diameter | about 66.7 in |
| Tire pressure | 22 PSI, 20 PSI |
| Loaded rear tire ballast / fluid capacity | 35 gal |
Tire Size Comparison Chart
Front rim diameter comparison
Rear rim diameter comparison
Benchmarks use typical low, average and high rim diameters for the utility / row-crop / large ag tractor category, not scraped low/high outliers.
Kubota M135GX Extra Tire Notes
| Tire size note | The Kubota M135GX uses different front and rear tire sizes in this data: front 420/70R24 (24 in rim, 420 mm width) and rear 520/70R38 (38 in rim, 520 mm width) |
|---|---|
| Multiple setup note | This data has more than one tire setup for the Kubota M135GX. The main front/rear listing is Front 420/70R24, Rear 520/70R38. Other setup data found: Front 14.9R24, Rear 18.4R38; Front 18.4R38, Rear 14.9R24. This usually means different wheel, axle, turf/ag/industrial, or market options rather than one universal tire size |
| Pressure note | For the Kubota M135GX with front 420/70R24 and rear 520/70R38 tires, the pressure values captured in the answer are 22 PSI, 20 PSI. Tire pressure is load-dependent, so use this as a reference value rather than a universal setting |
| Ballast note | For the Kubota M135GX rear 520/70R38 tires, the ballast figure captured in the answer is 35 gal. Liquid ballast capacity can change by tire brand, fill percentage, wheel setup and ballast fluid type |
Official information note
Mistakes do happen. Tire sizes can change by year, axle, wheel/rim option, tyre brand, tread type and local market. Please check the tire sidewall, operator manual and official kubotausa.com website for official information.


