Magnetic sump plug for gearbox - Dude - {P}
I am thinking of taking H.J`s advice and getting the gearbox oil changed after the first service, and would like to hear from any B.R. members who know where to locate a gearbox magnetic sump plug ?? Thanks.
Magnetic sump plug for gearbox - frostbite
Going back about 100 yrs to my schooldays, I believe you can turn your existing one into magnetic by stroking it with a good strong magnet.

Unless it's alloy, of course!
Magnetic sump plug for gearbox - Armitage Shanks{P}
You should be able to get a small magnet and Araldite it to the existing plug. Loudspeakers seem to have very powerful magnets, if you can find a scrap one.
Magnetic sump plug for gearbox - martint123
Araldite the magnet to the outside of the drain plug.

Count yourself lucky nowadays if you really have a drain plug.
Magnetic sump plug for gearbox - Dizzy {P}
For many years I have converted my various Triumph engine and gearbox drain plugs to magnetic by drilling a blind hole in the threaded end of the plug and aralditing a stick magnet into it. However, I've rarely (if ever?) found anything sticking to them so I'm not sure it's worth doing - except for peace of mind perhaps.
Magnetic sump plug for gearbox - Cliff Pope
For many years I have converted my various Triumph engine and
gearbox drain plugs to magnetic by drilling a blind hole in
the threaded end of the plug and aralditing a stick magnet
into it. However, I've rarely (if ever?) found anything sticking to
them so I'm not sure it's worth doing - except for
peace of mind perhaps.


That's because the bits that wear - bearing shells,thrust washers, selector forks etc, aren't made of iron or steel! And if you do chip a tooth off a cog it has probably done its worst before it finds the magnet.
Magnetic sump plug for gearbox - eMBe {P}
>> magnetic sump plug ?? >>


Can you explain what purpose you want it to be magnetic for?
(eg. Is it to stop falling out of your hand as you manouvre it? or is it a "snake oil" theory?)
Magnetic sump plug for gearbox - Andrew-T
eMBe - the plug collects all the swarf and steel bits worn off the engine innards, so they can be removed with more certainty during an oil change. BL cars had them in the 60s/70s, and the plug used to look frizzy with the bits stuck to it.
Magnetic sump plug for gearbox - Dizzy {P}
Andrew,

I think Cliff is correct in saying that most wearing bits will be non-ferrous. In any case, I assume that once the 'swarf and steel bits' have found there way to the bottom of the sump they are either going to stay there until the oil is drained or they will be taken out by the filter.

Were the BL cars of the '60s that you refer to Minis or 1100s by any chance? I think the situation with them might be different because they had the gearbox in the sump.

I've an idea that one of my Triumphs had a magnet as standard; perhaps Cliff will know as I think he also has a big Triumph.

One of our Perkins Engines customers also demanded a magnetic drain plug for a time but they took only about 50 engines per year and I assume that this was a case of a small firm prepared to pay a tiny bit more for 'belt and braces' protection.
Magnetic sump plug for gearbox - Dizzy {P}
Just realised that Dude was asking about fitting a magnetic plug to a gearbox, not engine. I think that is a sensible idea, though again my own gearbox magnetic plug was perfectly clean last time I looked. My gearbox is filled with synthetic oil which helps ensure clean gearchanges, thus avoiding metal chippings coming off the gears.
Magnetic sump plug for gearbox - Cliff Pope
I've an idea that one of my Triumphs had a magnet
as standard; perhaps Cliff will know as I think he also
has a big Triumph.


I have just drained and changed oil, axle and engine oils on 2 cars (2000 Mk1 and Volvo 240) and ONE of them indeed had a domed magnet inside, but I can't remember for certain which it was!
On reflection, almost certainly the Triumph box. It never collects any swarf though.
Also the Volvo overdrive sump has a large magnetic washer under the filter plug. Nothing has ever collected there either, despite 283,000 miles.

Conclusion:- they serve no purpose, unless to tell you your gearbox is already terminally ill.
Magnetic sump plug for gearbox - Dude - {P}
Thanks for your replies, it seems from what Cliff is saying that after 283k in his Volvo without any sign of swarf, that it is totally unecessary.!!!

If after that mileage without any signs of metal deposits, I am beginning to question the need to change the gear oil as well, and wonder if it is really needed with more accurately machined gears and the latest synthetic oils ???
Magnetic sump plug for gearbox - eMBe {P}
eMBe - the plug collects all the swarf and steel bits
worn off the engine innards,>>


So it was snake oil theory after all. Make sure you don't use Magnatec - it will stick to the magnet! ;-)

P.S. By any chance, do you also believe in those electronic/magnetic water softener devices on your domestic water systems? ;-)
Magnetic sump plug for gearbox - lezebre
When I changed the gearbox factory-fill after a year and a bit,
it was full of tiny bronze metal particles in suspension, and I was glad I'd followed the advice on this site to do a change after the 'running in'.
Magnetic sump plug for gearbox - none
All of the medium weight commercial vehicles I work on have magnetic gearbox and diff drain plugs. And they work.
MAN gearbox oil changes are recommended at 250,000km - so the manufacturer expects the box to last, and the drain plug plays a part.
Magnetic sump plug for gearbox - none
Whilst I'm still thinking about it, non drainable fwd Ford gearboxes have a magnet inside them.
Magnetic sump plug for gearbox - Cliff Pope
Just to clarify, I wasn't saying the gearbox has run for 283,000 miles without an oil change, far from it. In fact I am a firm believer in frequent oil changes in everything - it is the main thing that makes them last.
I was merely observing that the magnetic ring (separately accessible at major services on the Volvo) appeared to have been superfluous.
Magnet or not, it's changing the oil that is important, and of course keeping it topped up to level in between.
Magnetic sump plug for gearbox - GGH
I have fitted internal magnetic engine and gearbox/diff drain plugs to every car I have owned (since 1965). I mainly use a 3/16 rod magnet using an interference fit and loklited into the plug.

The BMC Mini had them fitted as standard, and I am told the VW Golf 086 type gearbox has them fixed to the inside of the casing as supplied.
Magnetic sump plug for gearbox - CMark {P}
Dude, "magnetic drain plug" gets around 41,000 hits on Google including www.magneticdrainplugs.com ! There is a lot of companies selling them including many tuning outfits. Plenty of vehicle and bike manufacturers used to/ still do fit them as standard and not just to gearboxes.

My 1986 Range Rover has one on its LT77 gearbox and it was pretty hairy last time I cleaned it a few months ago. Same for the automatic gearbox sump on the Grand Cherokee.

The presence of fuzzy metal particles and small amounts of paste is considered normal wear, larger chips are not and necessitate a further inspection.

eMBe, this is no snake oil theory. According to one webpage I found [1] "In one easy step, you can drastically reduce the wear and tear on your engine components [after fitting a magnetic sump plug]. After one oil change, you'll be a believer when you see how much "gunk" the plugs collect!" TIC.

Another website selling magnetic plugs [2] quotes: "Magnetic plugs are endorsed by the Society of Automobile (sic) Engineers as reducing wear.[3] "

Cliff, Why do you think so many manufacturers went to the trouble and expense of fitting these things as standard if they served no purpose?

GGH, wow, that is keen. What are your findings? You obviously find it useful, but why?

[1] www.sounddomain.com/sku/SPNALL90009000
[2] www.superplug.com/qa.html
[3] actually I think that should read Automotive. Tssk, these info-ads are hopeless really.
Magnetic sump plug for gearbox - Hugo {P}
Not Directly motoring related, but this will amuse the engineers among you.

Several years ago a colleague was trying to deal with the problem of swarf removal from a £0.5M CNC 5 Axis Machining Centre, built out of steel with a cast iron sump for weight. Although it had a filter to take the swarf out of the coolent, which recycled via the sump and was pumped out onto the job again, this arrangment was not completely effective due to the design of the machine.

He came up with the bright idea of ordering these huge magnets, had a tool fabricated to enable him to place them inside the sump and collect them again at regular intervals to clean the swarf off.

The idea was great in thery but after I sat him down and asked exactly how he was going to overcome the not insignificant magnetic force to remove said magnets from sump (never mind the swarf), he looked like all his christmases had been cancelled for life!

We came up with the idea of placing these magnets near the outside of the sump, with a block of wood in between, that allowed the light swarf to collect on the temporarily magnetised area of the sump, but allowed easy removal to kill the magnetism on the sump to allow easy cleaning.

This could be applied to larger mechanical applications involved with motoring etc - You see Mark it is motoring related!

H
Magnetic sump plug for gearbox - Cliff Pope

Cliff, Why do you think so many manufacturers went to the
trouble and expense of fitting these things as standard if they
served no purpose?

Becaue they must be cheap, and to save arguments and claims from people who didn't change the oil regularly?
IMHO oil changes are best, magnets a rather poor substitute for proper servicing.
Magnetic sump plug for gearbox - rg
CMark,

Ditto.

"A Very Old Mechanic That I have Known For Some Time" who served over fifty years on everything from R-R Merlins to Jags to Earth Moving Plant says that some sludge and filings is a normal find.

rg
Magnetic sump plug for gearbox - GGH
CMark

Apart from what you would expect to find on a magnetic sump plug, I have found the following interesting bits before it was too late.

1. Parts from the needle roller bearing from the transfer idler gear on a BMC Cooper S
2. Part of a Ferrari 275GTB (long nose) crankshaft timing chain sprocket.
3. Parts from the oil pump drive of a Merc 300SL Gullwing.
4. Half of a roll pin from the oil pump drive on a Dolomite Sprint.
5. Lotus Elan S4 SE Camshalf bearing cap dowel.
I have even fitted magnetic plugs to my Hayter and John Deer/Bolens lawnmowers.

I think they are worth fitting, I would not like to be without them.
Magnetic sump plug for gearbox - none
Back in the 70's I worked in a Skoda garage. We often used to get cars towed in with the owner complaining that since he'd changed the gearbox oil, gear selection was difficult or impossible. The Skoda drain plug was a tapered one and it was easy to overtighten it enough for it to jam the selectors.
DIY magnet fitters should beware.
Magnetic sump plug for gearbox - James_Jameson
Porsche fitted a magnetic drain plug to my 911; I believe this is common practice for Porsche.

 

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