Quick answer:
The John Deere 8400 tractor tire size is front 14.9R34 and the rear is 18.4R46.
Front tire14.9R34
Rear tire18.4R46
Front/rear setupDifferent front and rear tire sizes
Rim diameter34 in front, 46 in rear
John Deere 8400 Tire Size Details
| Front tire size | 14.9R34 |
|---|---|
| Rear tire size | 18.4R46 |
| Front/rear setup | Different front and rear tire sizes |
| Front tire construction | Imperial radial |
| Rear tire construction | Imperial radial |
| Front section width | 14.9 in |
| Rear section width | 18.4 in |
| Front rim diameter | 34 in |
| Rear rim diameter | 46 in |
| Tire size alternatives / conversions | 18.4R46, 20.8R42 |
Tire Size Comparison Chart
Front rim diameter comparison
Rear rim diameter comparison
John Deere 8400 Extra Tire Notes
| Tire size note | The John Deere 8400 uses different front and rear tire sizes in this data: front 14.9R34 (34 in rim, 14.9 in width) and rear 18.4R46 (46 in rim, 18.4 in width) |
|---|---|
| Front/rear matching note | The John Deere 8400 data shows front 14.9R34 and rear 18.4R46. When changing either size, front/rear rolling circumference and lead/lag need to stay within the correct range |
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 deere.com website for official information.







