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Thoughts on putting a magnet inside a final drive?

skata

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May 10, 2007
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What do you guys think of placing a strong magnet on the inside of a planetary? To catch metal particles. Behind the cover. Or perhaps getting one of them very large magnets and just sticking it on the outside of the planetary cover?
 

56wrench

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Dec 4, 2016
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alberta
usually, the magnetic plugs used in gearboxes and planetaries are made with the magnet epoxied in and flush with the end of the plug. that would allow for 'fuzz' to stick and not be grabbed by passing gears provided there is adequate clearance. plus it is easy to remove periodically for inspection and cleaning
 

skata

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May 10, 2007
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I bought some fishing magnets off Amazon. And these are the smaller versions. I can't get it off without some serious prying. Should I leave them in there? 0929202158_HDR.jpg 0929202158a_HDR.jpg 0929202158b_HDR.jpg
 

Tugger2

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Mar 22, 2018
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British Columbia
Id stick with the threaded plug. If your finals are spitting out so much metal you need a big magnet to collect it they are gonna be toast anyhow.
 

hosspuller

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May take serious prying, but consider a bump or drop while traveling. Or a series of bumps over the years. Things that are tight at first seem to loosen over time. If it falls off, will it be captured in a safe place? Magnets in sumps have gravity to help hold them safely. That's the true answer to your question.

Edit to add: if the magnet is on a component... would the magnetism attract metal particles to meshing parts instead of allowing the oil to flush them away ? Seems the drain plug location is clearly safe.
 
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skata

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Magnet is on cover. Neodymium magnets lose very little magnetism over time, and take heat well. Even if it were to slide for some reason, it would still be on the cover where nothing will touch it. If you saw my other thread about having lot of metal particles, you'd understand why I want a magnet in there. A gentleman from a drive rebuild service told me that the wear wasn't too bad and to just change the oil frequently. So hopefully this magnet keeps the metal suspended in the oil to a minimum. So either this will work, or I'll be buying new drives soon!
even by grabbing the magnet with both hands, it won't move. It's amazing how well these stick. Supposedly need over 400lbs force to pull off straight. Amazon has bigger ones that go over 1000lbs force!
 
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Delmer

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Jan 3, 2013
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WI
Do you really want to take that cover off to clean the magnet? You can pull the plug and check it and clean it every hour if you feel like it.
 

skata

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May 10, 2007
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midwest
Do you really want to take that cover off to clean the magnet? You can pull the plug and check it and clean it every hour if you feel like it.
It's really not that hard to remove the cover. Zip the bolts off, hit the cover with a mallet, and it's off. I tried little magnets (1/2")on the plug ends, but they didn't grab real strong. And considering the amount of metal flakes I had in the oil, I wanted a bigger magnet.
 

Volvomad

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Jul 13, 2011
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Like Delmer said . A small secure magnet that you can remove easy and as often as you like is the way to go . It is like free basic oil sampling and will always be a benefit .
 

skata

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May 10, 2007
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I ran the machine for an hour, and decided to remove the cover just to make sure the magnet didn't move. I didn't really do a thorough cleaning of the planetaries, so there was still flakes inside. The magnet actually works good. And it didn't move. And no visible flakes in the oil. 1005201836_HDR.jpg 1005201836a_HDR.jpg
1005201845.jpg
 

Philip_Green

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skata

Senior Member
Joined
May 10, 2007
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1,541
Location
midwest
So while I had it off again, I asked a local machine shop to machine a recessed flat for the magnet, to better keep it in position. 1006201640.jpg 1006201640a.jpg 1006201640b.jpg
 

rsherril

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May 2, 2009
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Maybe put it on the outside of the housing near the drain plug? Lots of uses for magnets on yellow iron.
 
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