The John Deere 8970 tractor tire size is front 20.8R38 and the rear is 710/70R38.
Front tire20.8R38
Rear tire710/70R38
Front/rear setupDifferent front and rear tire sizes
Tire pressure18 PSI, 35 PSI
Rim diameter38 in front/rear
Ballast50 gal
John Deere 8970 Tire Size Details
Front tire size
20.8R38
Rear tire size
710/70R38
Front/rear setup
Different front and rear tire sizes
R1 ag tire size
20.8R38, 18.4R46
Front tire construction
Imperial radial
Rear tire construction
Metric radial
Front section width
20.8 in
Rear section width
710 mm
Rear aspect ratio
70%
Front rim diameter
38 in
Rear rim diameter
38 in
Approx rear overall diameter
about 77.1 in
Tire pressure
18 PSI, 35 PSI
Loaded rear tire ballast / fluid capacity
50 gal
Tire size alternatives / conversions
30.5-32, 710/70R38
Tire Size Comparison Chart
Front rim diameter comparison
This model
38 in
Average
17.1 in
Low
4 in
High
50 in
Rear rim diameter comparison
This model
38 in
Average
25.5 in
Low
0 in
High
50 in
John Deere 8970 Extra Tire Notes
Tire size note
The John Deere 8970 uses different front and rear tire sizes in this data: front 20.8R38 (38 in rim, 20.8 in width) and rear 710/70R38 (38 in rim, 710 mm width)
Pressure note
For the John Deere 8970 with front 20.8R38 and rear 710/70R38 tires, the pressure values captured in the answer are 18 PSI, 35 PSI. Tire pressure is load-dependent, so use this as a reference value rather than a universal setting
Ballast note
For the John Deere 8970 rear 710/70R38 tires, the ballast figure captured in the answer is 50 gal. Liquid ballast capacity can change by tire brand, fill percentage, wheel setup and ballast fluid type
Front/rear matching note
The John Deere 8970 data shows front 20.8R38 and rear 710/70R38. 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.
