The Stovebolt Site Forums The Shop Area Engine Shop Magnets and Filters

Rainy weekend, that means a couple days in the shop darn it!

Changed hydraulic/HST transmission oil (shared system), engine oil, fuel and air filters on the Kubota. First time I noticed that one of the trans/hydraulic filters had a large round magnet on the top of the filter. It had a film of very fine metal shavings on it. Much like you see in the bottom of an automatic trans pan.

Truck point - a magnet was not on the engine oil filter, so assuming that doing so would not be beneficial to the engine oil system which is why we don't see these on modern vehicles or even SBC's....and by extension wouldn't help on our old trucks. Just catch the big stuff with a magnet on the bottom of the pan, or metallic plug. Makes sense?

You do see magnets a lot in automatic transmission, Allison uses them in the pans and on the filters. Having one on the engine oil filter sure wouldn't. I have seen magnets for oil filter, but never installed ones from a factor.
Makes sense to me,

Joe

The only places magnetic wear particles might come from on a stovebolt engine would be the camshaft, lifters, distributor gear, etc, and maybe a little internal wear in the oil pump. Most other bearing surfaces have soft metal running against steel, such as rod and main bearings, timing gears and such, and even if those parts wear, a magnet would be of limited benefit. Cast iron pistons and cylinder walls are magnetic, but wouldn't the wear particles from them be trapped by a bypass oil filter?
Jerry

I like the idea of a magnetic drain plug. I can look at it at every oil change and cringe if there is a bunch of iron on it.
Without that I can only guess what is in the filter.
Maybe I should rethink using a magnetic drain plug.
Sometimes ignorance can be bliss...
If I think about it, what am I going to do if I see metal on the magnet? Stop driving? Tear it down? Nope.
Carl

So are the magnets on the Kubota filters there just to indicate "if" there is any metal, and the filter actually catches the damaging particles? A feature provided to freak out Carl like people?

I have noticed that the drain plugs of various transmissions and transfer cases sometimes have a magnet, but they have no other filtration system.

Interesting topic.

The magnets are upstream of the filter material. I'm thinking the magnet catches the larger particles and let's the filter grab the even finer ones. The particles on the magnet were very fine, essentially a gray film. All in the design and understanding that metal to metal parts wear. We know our disc brake pads wear a little every time we touch the brake pedal, but most of us don't go high ratio when we see the brake dust on our fancy wheels.