Caterpillar 346-6693 Air Filter (966F / 966F II, Square Housing)

One Element, Two Cat Numbers — Which One Is Yours

Cat sells the same square-housing primary element under two part numbers, and both are still live in the parts store: 346-6693 and 539-6920. Open either page on parts.cat.com and you get the same four figures — 8.016 in overall width, 8.327 in overall depth, 13.228 in overall height, shape listed as non-round — with the same type entry, primary, and the same material, moulded thermoplastic ends. The aftermarket agrees: Donaldson's own competitive-fit table puts one number, P636408, against the C34540/1, PA30275, AF4243 and WA10115 family that carries both Cat numbers, and the supplier catalogues that quote Baldwin PA30275 or Fleetguard AF4243 quote them against 346-6693 and 539-6920 interchangeably.

So why does the number matter at all? Because the machine lists are not identical. The 966F and 966F II wheel loaders sit on Cat's 346-6693 list. They do not appear on Cat's 539-6920 list. On the other side of the same split, the 963K track loader, the PL61 pipelayer, the 140 GC motor grader, the M314F to M323F wheeled excavators, the AP1000 and AP1055 / BG paver range and the TR16-C7.1 transmission sit on the 539-6920 list and not on 346-6693. If you are stocking a shelf for a mixed fleet, that is not a cosmetic difference — it decides which number you should hold.

What the Two Numbers Actually Measure

Non-round elements cannot be described with a diameter, and that is exactly why suppliers get this one wrong. Cat publishes three figures, and the third one is the one people forget: the height of the pleated pack, 13.228 in. An aftermarket catalogue for the same element reads 336.4 mm long, 202 mm wide and 215 mm high, which agrees with Cat's 336.0 mm, 203.6 mm and 211.5 mm to within a few millimetres. A supplier who tells you a 539-6920 element is a cylinder with a diameter has described a different part.

The safety element behind it is a different shape again: 346-6694 at 6.594 in wide, 1.484 in deep and 11.634 in high. It is thin, it sits inside the primary, and it is ordered on its own line. Cat's filters guidance on the secondary element is blunt — never clean it, and change it with every third primary change or as required. Blowing it out with compressed air pushes the retained dust deeper into the media.

Where This Element Turns Up Beyond Dozers

Buyers who file this number under "dozer air filter" under-order it. The same square air cleaner runs on the 966F and 966F II wheel loaders, the 953K track loader, the AP600F and AP655F pavers and the MH3037 material handler, and it is shared with the 2384C, 2384D, 2484C, 2484D, 559C, 559D, 579C and 579D knuckleboom loaders. For a 966F or 966F II working in aggregate handling, quarry feed or a port bulk yard, the air cleaner is doing the same job it does on a dozer — pulling dust out of an intake in a cloud of it — and the element behind it is this one.

What We Do Not Publish

No price, because the honest variable is quantity, lane and whether you take the pair or the full service kit. No hour interval, because that belongs to the machine manual rather than to a web page. And no claim that the two Cat numbers are formally superseded, because Cat still lists both: what we can show you is identical published figures, one aftermarket replacement number covering both, and two different machine lists. If your parts book says 346-6693, take 346-6693. Send the serial prefix off the PIN plate, the air cleaner group number, or a photo of the old element beside a tape measure, and we confirm the primary and the secondary, quote both, and ship in 3–7 days, FOB Shanghai or CIF to your port.

FAQ

Q: Is Cat 346-6693 the same filter as Cat 539-6920?
A: By the published figures, yes. Cat's parts store gives both numbers the same specification sheet — standard efficiency primary, non-round, 8.016 in overall width, 8.327 in overall depth, 13.228 in overall height, thermoplastic ends. Aftermarket suppliers treat them as one element too: a single Donaldson number, P636408, is listed as the competitive-fit replacement for both Cat numbers, and Baldwin PA30275, Fleetguard AF4243, MANN C34540/1, HIFI SA17479 and WIX WA10115 appear against both. The difference is the machine list, not the filter: Cat lists 346-6693 against the 966F and 966F II wheel loaders, and 539-6920 is not listed on those two machines.

Q: What are the dimensions of Cat 346-6693?
A: Cat's parts store publishes 8.016 in (203.6 mm) overall width, 8.327 in (211.5 mm) overall depth and 13.228 in (336.0 mm) overall height, shape non-round, media type standard, material thermoplastic plastic. Aftermarket catalogue figures for the same element read 336.4 mm long, 202 mm wide and 215 mm high, which agrees to within a few millimetres. Because the element is not round, measure width, depth and pleat height rather than a single diameter.

Q: Which machines does 346-6693 cover that 539-6920 does not?
A: On Cat's own fitment lists, the 966F and 966F II wheel loaders and the MH3037 material handler appear under 346-6693 only. The reverse also happens: 963K track loader, PL61 pipelayer, 140 GC motor grader, the M314F to M323F wheeled excavators, the AP1000 and AP1055 / BG paver range and the TR16-C7.1 transmission appear under 539-6920 only. Both lists carry the D6N, D6K2, D4, D5R2, 953K, AP600F and AP655F and the 2384C to 579D knuckleboom loaders.

Q: Do I need a second element with 346-6693?
A: Yes. 346-6693 is the outer (primary) element. The secondary or safety element that sits behind it is 346-6694, a thin non-round element measuring 6.594 in wide, 1.484 in deep and 11.634 in high, and it is a separate purchase. Cat's filters guidance says the secondary element should never be cleaned and should be changed with every third primary element change or as required.