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Magnets on Outside of Oil Pan

Does it make sense to put magnets on the outside of your oil pan to collect metal contents? On either the transmission or crank case.

No. That’s why your engine and transmission have filters. Anyway, magnets wouldn’t have any effect on nonferrous metals like aluminum. If you’re concerned about metal pieces in your oil/transmission fluid you have serious problems.


Some transmission pans do have magnets.

But transmission pans are removed to replace the filter when serviced.

That gives an idea of the condition of the transmission.

The engine oil pan isn’t removed for regular service. So a magnet inside/outside the pan provides no benefit unless the pan is removed.



If there is enough debris floating around in your transmission or engine that a magnet on the outside will retain it you’ll be replacing the engine or trans very shortly. Your engine has an oil filter that’s replaced at every oil change. Many transmissions have a filter that gets changed when the fluid is replaced. That’s all you need.

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You used to be able to buy magnetic oil drain plugs for your oil pan. Maybe you still can. Every Chrysler product with an automatic transmission that I changed the fluid and filter on had magnets in the pan but you would not know about it unless you did your own maintenance.

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What about all the videos on YouTube where people cut open oil filters that had magnets on them, and there is metallic material on the filter where the magnets were. Like here for example:
So what I’m saying is why not just include magnets on the outside of the pan to do the same thing, given that we know they help on the outside of filters. I know that transmissions have magnets already installed on the oil pan normally. But is there a benefit to adding more either on the inside or the outside of the oil pan?


Why though?

John , if you want magnets on your oil pan just do it . If it makes you feel better , fine.

The magnet on the oil filter is collecting metal that would otherwise have been filtered out by the filter. No harm done, but no benefit, either.

Another reason I see no need - of the hundreds of problems we get asked about, I don’t remember any related to metal filings in oil that was changed as specified by the maker.

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The wet clutches in most automatic transmissions produce dust from the friction of the dozens of discs, much of which accumulates on the pan magnets. And I have always assumed that the difference in severe and normal duty service intervals on transmission is significantly determined by the level of wear and resulting metal dust generated. Transmission pan magnets are usually loaded with black iron from the plates and if the magnets become fully loaded eventually the filter will be plugged with the dust. And what happens then is expensive.

I do not recall on what particular car, but previously I found a strong magnet embedded into a transmission pan plug, it was quite convenient to check it when you drain/refill, as it was a good indicator of the wear

The transmission plug on my wife’s 96 Accord was magnetic.

But more and more vehicle engines are aluminum.

Magnets only attract ferrous metals. Failures related to crank bearings, cam bushings or saddles, etc will not be attracted to any magnet,
Problems with automatic transmissions are generally related to bushings, clutches, and rubber seals. None of this will stick to a magnet.
This could work with a manual transmission except that it won’t attract synchronizer material which is made of brass,.

Forget the idea. It’s pointless and as mentioned if you have a debris problem anywhere the life expectancy of that unit is going to be short.

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But what if it is metal that won’t be collected by the filter. Like something smaller than 20 microns, the magnet will pick it up but not the filter. Maybe put around oil filter, and add several more magnets to the transmission oil pan?

You can buy oil filter magnets.;_ylt=AwrJ7FTS51VeOiEAQJ9pCWVH;_ylu=X3oDMTB0N2Noc21lBGNvbG8DYmYxBHBvcwMxBHZ0aWQDBHNlYwNwaXZz?q=oil+filter+magnet&s_it=searchtabs&v_t=comsearch

But in order to see what magnet collected, you’d have to cut the oil filter open.

Who the hell wants to go thru that messy job?


Knock yourself out. Waste of time and money, in my opinion.

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I think it could do some good in some situations. I certainly don’t see how it could hurt other than the magnets falling off when going over a bump and bouncing around and damaging something else (or another car behind you). If you try it, be sure to remove the magnets before draining the oil, otherwise the metal debris stuck to the magnets will stay inside the pan. I’d guess a magnetic-drain plug is a better solution.