Why do filter part numbers change?

[BeezFun]

The part number for the hydraulic filters on my tractor have been superceded 3-4 times during the time I've owned it. Why do part numbers get updated, it looks like exactly the same filter from the outside. Are they different inside?

 

[RickB]

Sometimes. Often it is a manufacturer change or even just a manufacturing facility change.

 

[Midniteoyl]

The part number for the hydraulic filters on my tractor have been superceded 3-4 times during the time I've owned it. Why do part numbers get updated, it looks like exactly the same filter from the outside. Are they different inside?

Mostly its a supplier change.

 

[BeezFun]

Mostly its a supplier change.

I had always imagined that a company like Kubota might have one or more suppliers for the same part, so supplier A might call the part an X42C and supplier B calls the same part made to the same Kubota spec a Z72D, and when Kubota sells it to me they make up a part number like HH720-12345. I would have thought they'd keep track of which supplier produced which parts by tracking the lot numbers they ship out. So if there are problems with a group of parts they can figure out which lot number and then which supplier they came from. It had not occurred to me they would change part numbers if they started buying the parts from a different supplier.

 

[Roadworthy]

Perhaps it's serendipity. For years my car and my pickup (a Ford and a Dodge) used the same oil filter by Bosch. Now they each have a different part number. One is very similar to the original pickup filter. The car filter is smaller in diameter. Either filter will work in either location. The engines haven't changed, only the filters. I guess it's one of life's unexplained mysteries.

 

[BeezFun]

There's probably someone in the company whose job is to keep track of the part number change history. In order to increase the size of their department they continually change the part numbers.

 

[RickB]

There's probably someone in the company whose job is to keep track of the part number change history. In order to increase the size of their department they continually change the part numbers.

Any well constructed electronic parts catalog will include access to the complete supercession chain for any current part with prior part numbers. This is often dealer-only info.

 

[jjeff]

It sure is annoying, I remember when I first got my 2850 no Kubota dealers close by spent a half hour or so helping the parts guy thumb thru books at Napa finally finding filters made by fleet guard equivalent to Kubotas.

 

[Midniteoyl]

I had always imagined that a company like Kubota might have one or more suppliers for the same part, so supplier A might call the part an X42C and supplier B calls the same part made to the same Kubota spec a Z72D, and when Kubota sells it to me they make up a part number like HH720-12345. I would have thought they'd keep track of which supplier produced which parts by tracking the lot numbers they ship out. So if there are problems with a group of parts they can figure out which lot number and then which supplier they came from. It had not occurred to me they would change part numbers if they started buying the parts from a different supplier.

That's why places like Harbor Freight have different SKU's for the same item; same 'model', same specs, different supplier.

 

[BeezFun]

Did some research on this, turns out there are manufacturing standards for when to change part numbers. I'd conclude from what I found that there is some material difference in the new oil filter I bought or they wouldn't have changed the part number. I can imagine if they want to use the same oil filter on 10 different engines and the newest engine needs a 2 micron filter and all the old ones only needed a 4 micron filter, they change the part number on all the old engines to use the new 2 micron filter so they can buy a million of one kind of filter and save money.

Here's the most succinct explanation I could find, there's a whole industry devoted to defining this kind of stuff: