Quick answer:
The John Deere 3120 tractor primary engine air filter part number found is AM125424. Cross-reference filters include WIX 51056; NAPA 1056; Baldwin B7165; FRAM PH8172. Filter dimensions found include Height: 3.5 in / 89 mm; Outer diameter: 3 in / 76 mm; Inner diameter: 0.75 in / 19 mm. Service guidance is to check the air filter every 50 hours.
Primary air filterAM125424
Cross-referenceWIX 51056
Filter height3.5 in / 89 mm
Engine power29.5 hp
Service intervalCheck every 50 hours
John Deere 3120 Air Filter Specs
| Primary air filter part number | AM125424 |
|---|---|
| Secondary / safety air filter | AN403919 |
| Pre-filter | RE68048 |
| Cross-reference filters | WIX 51056; NAPA 1056; Baldwin B7165; FRAM PH8172 |
| Air filter size | Height: 3.5 in / 89 mm; Outer diameter: 3 in / 76 mm; Inner diameter: 0.75 in / 19 mm |
| Filter height | 3.5 in / 89 mm |
| Outer diameter | 3 in / 76 mm |
| Inner diameter | 0.75 in / 19 mm |
| Replacement interval | Check every 50 hours |
| Number of air filter elements | 3 elements (primary, secondary, pre-filter) |
| Engine horsepower | 29.5 hp |
| Engine displacement | 91.5 cu in (1.5 L) |
John Deere 3120 Air Filter Charts
Air filter dimensions
Engine horsepower
Engine displacement
Air filter service interval
John Deere 3120 Air Filter FAQ
| What air filter does the John Deere 3120 use? | The primary engine air filter part number found for the John Deere 3120 is AM125424. |
|---|---|
| What air filter cross-references fit the John Deere 3120? | Cross-reference filters found for the John Deere 3120 include WIX 51056; NAPA 1056; Baldwin B7165; FRAM PH8172. |
| Can I use an aftermarket air filter on the John Deere 3120? | The John Deere 3120 has 4 cross-reference filters listed, starting with WIX 51056. For aftermarket buying, compare brand part number, dimensions, seal shape and air-cleaner housing fit. |
| What size is the John Deere 3120 air filter? | The air filter dimensions found for the John Deere 3120 are Height: 3.5 in / 89 mm; Outer diameter: 3 in / 76 mm; Inner diameter: 0.75 in / 19 mm. Use these dimensions as a fit check, but treat the part number as the main match. |
| How often should the John Deere 3120 air filter be checked or replaced? | The service guidance found for the John Deere 3120 is to check the air filter every 50 hours. That is shorter than the reference average of 100 hours for this class, so it points to more frequent inspection rather than a long replacement-only interval. |
| How many air filter elements are listed for the John Deere 3120? | This page lists a primary filter, a safety filter and a pre-filter: 3 elements (primary, secondary, pre-filter). Replace each only with the matching part number for that position. |
| Why include engine specs on a John Deere 3120 air filter page? | The engine data kept for the John Deere 3120 is 29.5 hp, 91.5 cu in (1.5 L). Use it as supporting context only; the actual filter match is still driven by the air-cleaner housing and part number AM125424. |
| Should I order the John Deere 3120 air filter by size or part number? | Use AM125424 as the main match for the John Deere 3120. The cross-reference list helps find aftermarket options, while the measured dimensions helps avoid ordering a filter that does not seat correctly. |
Official information note
Air filter fit can change by engine, serial number, production year and air-cleaner housing. Check the operator manual, parts manual and official deere.com website before buying or fitting an air filter.

