Magnetic Drain Plugs

[Geo Hahn]

A friend had his TR3 gearbox turn into an IED when a long-ago broken 2nd gear tooth finally migrated to a place where it could jam up the works.

Many think you cannot remove the bellhousing from a TR gearbox, strictly speaking... you can. In fact he didn't even have to stop the car to neatly separate it. They searched the roadside but never did find the driveshaft.

Anyway, not wanting to experience anything even vaguely resembling that fate and knowing that broken teeth on the lower gears is far from unknown... I got a couple of those magnetic drain plugs.

Geez, these things are wimpy. Your average refrigerator magnet is more powerful. No doubt they are enough to collect a bit of tiny ferrous swarf but if there is a significant piece of metal loose in the works this thing won't be able to hold it out of harms way.

I'm thinking I'll chip out the magnet it came with and replace it (JBWeld) with a neodymium button magnet (very strong). Can anyone think of a reason why this isn't a good thing to do?

 

[HerronScott]

Ouch, your friend was still driving the car with a bad second gear?

Scott

 

[dklawson]

I can think of no reason not to do what you suggest. In fact, I just did this to the drain plug for the 1500 engine that will be going into my project Spitfire.

On the Mini, the gearbox IS the sump for the engine oil. It is imperative to use a magnetic drain plug there as you are dealing with engine and gearbox swarf at the same time. The standard drain plug there uses a rare earth cylindrical magnet bonded with something into a drain bolt. I've never seen one of those come apart. JB Weld should work fine.

 

[TR3driver]

Not sure which plug you got, Geo, but mine (from MMC) have been strong enough to trap and hold significant chunks.

Scared me silly the first time I changed oil in my Stag after installing the magnetic plug in the oil pan, as it came out with half of a timing chain roller stuck to it! (Stags are famous for losing timing chains, followed by the pistons getting overly intimate with the valves and a very expensive engine rebuild.) But after tearing the timing case down for inspection, I concluded that the piece had been rolling around since before the DPO had changed the chains.

Be sure you roughen both surfaces and wash them thoroughly with acetone, so the JB Weld can get a grip. The plugs from MMC appear to have been put together this way as well, so I'm sure it will work.

I rather suspect your friend's scenario is also what happened to the "Uncle Jack" Stag, although I don't think they ever found where the piece came from.
https://triumphtransamerica.org.uk/?p=269

 

[TRDejaVu]

You got me checking the ones that I just bought; yep they are wimpy.

I previously "attached" a computer hard drive magnet next to the drain point on my sump - very strong. I may cut up another one and replace it as you suggest.

 

[dklawson]

Randall... MMC? McMaster? I see they do have assorted magnetic drain plugs in NPT sizes.

 

[Gordon_Dedrick]

And if you get all the gears magnetized correctly with a REALLY strong magnet you'll end up with magnetic drive!
Gordon

 

[tdskip]

Randall... MMC? McMaster?

Yep - that is them.

 

[TR3driver]

Randall... MMC? McMaster? I see they do have assorted magnetic drain plugs in NPT sizes.

Yup, that's them. I particularly like the hex socket plugs, as they are much less apt to round than the square-headed ones, and easier to work with in tight quarters. Also less hanging out to get snagged on a rock.

 

[JohnB]

Does anyone have a link or an address for McMaster?
Google didn't help and I'd like to check out their plugs

 

[PatGalvin]

https://www.mcmaster.com/#

 

[TR3driver]

https://www.mcmaster.com/#magnetic-pipe-fitting-plugs/=6l2ij6

 

[JohnB]

Thank you gentlemen ........I was trying to link McMaster with auto parts......