Saturday, February 26, 2011
Special Reader Donation: Magnetic Drain Plugs
Back in December, long time BMW owner and enthusiast Jim Craig found my blog one day and sent me an email to say thanks for the coverage. Like many readers do, he offered some suggestions for various issues I was having at the time and promised to send me a donation to help out. But instead of money, this self-described "maintenance junkie" offered to send me some of his handywork -- a set of drain plugs and a power steering cap bonded to strong magnets I could use to extract ferrous metals from my differential, engine, and power steering system.
I received the following parts a couple weeks later:
- Two differential plugs
- One engine oil sump plug
- One power steering reservoir cap
- One transmission fill plug (manual transmission only)
The differential drain plugs are the current style equipped with a gasket and do not require a metal sealing ring. The plugs are identical and are designed to replace the existing drain and fill plugs. Jim suggested that I could swap out the fill plug whenever I want and then swap the drain plug at the next oil change, so that's what I plan to do.
The oil drain plug should capture its share of ferrous metals from the engine oil. And if you're wondering why it's essential to use a magnet in a system equipped with a filter, it's simple: paper filter media captures particles as small as 25-30 microns, while magnets can attract particles as small as a few microns.
While the vast majority of the wear metals in the power steering system are non-ferrous in nature (aluminum, mostly), the gears are ferrous and I'm confident that any particles captured by the magnets will be unable to cause further damage to the power steering system.
As for the transmission fill plug, this is for the manual transmission only as the automatic transmission is already equipped with several magnets in the pan. I won't be able to use this (well, unless I wind up doing that auto to ZF 6 speed swap) but I present it here to show the complete set.
Which brings me to point out that while Jim is not mass producing these, he has offered to sell them as a set to interested parties for $50. Considering the cost of the raw materials I think that's a very fair price. If you're interested in buying a set, contact Jim directly for more information, and feel free to mention you learned about the set here. In the interest of full disclosure, I have received no compensation from him other than the original donation of this set of plugs, and will not benefit in any way from the transactions.