The Case IH Farmall DX21 tractor primary air filter part number is PA2684FN. The inner safety filter is 187472A1.
Case IH Farmall DX21 Air Filter Details
Primary air filter part number
PA2684FN
Inner safety air filter part number
187472A1
Outer air filter part number
AFS-0456F1
Air filter dimensions
Length: 10.4 in | Outside diameter: 2.4 in | Inside diameter: 1.8 in
Cross-reference part numbers
86519867, 86549701
Air Filter Service Interval Guide
Air Filter Service Interval Guide
Dusty use
100 hrs
Average
250 hrs
Light use
500 hrs
Listed Filter Size Check
Length
10.4 in
Outside diameter
2.4 in
Inside diameter
1.8 in
These are practical inspection/replacement guide ranges for the compact tractor category. Dusty work can shorten the interval heavily, so use the restriction indicator and operator manual first.
Case IH Farmall DX21 Extra Air Filter Notes
Engine model
Shibaura 1.0L
Engine displacement
1 L | 61 cu in
Engine horsepower
21 hp | 15.7 kW
Primary filter note
For the Case IH Farmall DX21, the listed primary air filter part number is PA2684FN. Match the number before buying because air cleaner setups can vary by engine, serial range and market.
Outer filter note
The listed outer air filter part number is AFS-0456F1.
Safety filter note
The listed inner safety air filter is 187472A1. Do not remove the safety element for normal cleaning; replace it if dirty, damaged or oil-soaked.
Fitment note
Listed dimensions: Length: 10.4 in | Outside diameter: 2.4 in | Inside diameter: 1.8 in. Use dimensions as a second check, not as the only buying method.
Filter size note
The listed dimensions point to a mid-size element length at 10.4 in and small outside diameter at 2.4 in. Use that as a fitment sanity check against the old filter.
Power range note
Use the power class to decide urgency. Higher airflow demand means less patience for questionable media, bad seals or packed pleats.
Engine airflow note
The displacement helps identify the engine family; horsepower tells you how hard it breathes under load. The element still has to match the canister.
Cross-reference note
Possible cross-reference numbers found for the Case IH Farmall DX21: 86519867, 86549701. Treat these as secondary checks after the primary filter number.
Service note
Clean loose dust from the air cleaner housing before pulling the filter. Never run the tractor with the filter removed, even for a quick test.
Case IH Farmall DX21 Air Filter FAQs
Does the Case IH Farmall DX21 filter size look right for its horsepower?
The useful read is not the raw size by itself. Compared with the 21 hp engine class, the listed element size is generous for the power class, so fit/seal checks matter more than chasing a bigger filter. Use that to decide how cautious to be in dusty work.
Should I order one filter or a full Case IH Farmall DX21 air-filter set?
For a full parts check, separate the service element from the safety element: buy the outer/primary service element first, then buy the inner safety element only if it is dirty, damaged or due. Do not accidentally order AFS-0456F1 when you meant the safety filter, or 187472A1 when you meant the outer filter.
Why should I compare the old Case IH Farmall DX21 filter before buying?
Treat PA2684FN as the hero value, not the whole truth. Serial range, engine swaps and different air-cleaner housings can beat a generic online listing.
Can I match a Case IH Farmall DX21 air filter by size?
A long, narrow element can still have different end caps across brands. Use size to narrow the search, then use the part number and seal style to make the decision.
Why does the full Case IH Farmall DX21 air-filter number matter?
The primary number format is a letter-prefix part number, while the page also has separate companion numbers. That is exactly where copy-paste ordering mistakes happen.
Why not stretch a dirty Case IH Farmall DX21 air filter under load?
Use the power class to decide urgency. Higher airflow demand means less patience for questionable media, bad seals or packed pleats.
Should I buy separate outer and primary filters for a Case IH Farmall DX21?
The presence of both outer and inner numbers means you should order carefully. A kit can be convenient, but only if it contains the correct service element and safety element.
Official information note
Mistakes do happen. Air filter specs can change by year, engine, serial range, market and air cleaner housing. Check the old filter, operator manual, parts book and official caseih.com website before ordering or installing an air filter.
