A question that seems hard to find an answer....
Type 9 box, bolted to an ST170 engine (in my spitfire)

I ask as I managed to smash the magnet in the bottom of the b=gearbox when I drilled for a drain plug (oops, I forget to check inside the case once the box was stripped) and so want to get a new magnet, but needs to be different size/shape. And magnets have different temp ratings.... (the really high temp ones are mega money)

Ta

Hi
we use neodymium and samarium cobalts both good for 150C+ and we have some development ones in different sizes,orientations what are you looking for and I'll see what we have.

Pete

should have said i recommend the Neodymium as the SmCo are quite brittle and fire shrapnel everywhere if you let them lose and they hit something.

I've never been burnt touching a gearbox casing, it gets hot but not that hot...

Are you smashing it around the track or pootling to the shops?

I also imagine it depends on the viscous rating of the oil, thicker stuff will get hotter. But as an educated guess 30-50 degrees in normal shopping mode. Around 60 degrees on metal is very hot on the bare hand, never been burnt by my gearboxes.

Yes, it does trackdays, autosolos plus long fast autobahn stuff (it absolutely drinks fuel over 100mph) and alpine passes. So not for tootling about

Watsonpj, thanks for the info. I have some smallish magnets here (had them for donkeys years) and they seem strong enough, and are about 8mm diameter and 5mm thick. I left one in boiling water for several hours, no change to magnetic strength, but didn't like being held just over a gas ring, fell off in a few seconds but that is probably 200 degrees or so. I will try one in teh oven this evening when we cook dinner!

I think most boxes have a magnet to catch the general swarf that is generated in a gearbox. Handy on a drain plug as you can see if there are any big bits (like circlips or teeth, one reason I gave up on Triumph mechanicals)

[Edited on 25/3/19 by cliftyhanger]

quote:

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Originally posted by Mr Whippy
I've never been burnt touching a gearbox casing, it gets hot but not that hot...

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quote:

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Originally posted by cliftyhanger
A question that seems hard to find an answer....
Type 9 box, bolted to an ST170 engine (in my spitfire)

I ask as I managed to smash the magnet in the bottom of the b=gearbox when I drilled for a drain plug (oops, I forget to check inside the case once the box was stripped) and so want to get a new magnet, but needs to be different size/shape. And magnets have different temp ratings.... (the really high temp ones are mega money)

Ta

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You will likely see 140degC ish gearbox oil temp at somewhere like Snetterton, not far off that on autobahn!

[Edited on 25/3/19 by AdamR20]

quote:

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Originally posted by FatChapChipChop


Bit late now, I know .. But, why drill the casing when a tapping into the sandwich plate will do it (with a BSP tap) as per BGH ?

Cheers !!

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When ever I have the sump off anything, I chuck /place a couple off these in the sump from ebay,

https://www.ebay.co.uk/itm/N35-Neodymium-Disc-Magnet-8mm-10mm-12mm-15mm-20mm-diameter-rare-earth-magnet/202345297625?var=&hash=item2f1cb836d9& ;enc=AQADAAADAFjVrDbVsZ8oH%2F8PNHtt9VX4%2Fw7FZcmMuqsX8uaFEduVeGryPcOvuHAkYCWMxNw8bopGlF1dKqyQ7c8ZlS5wGCaw8Ybz7dgT6d4EzkNLba7oxfypaDVtXw8YUyOI8yupeM3s5 9qMoz3YdCo4qDFm7EM1O4vNQA3VIMNEJP8HMasOSJDm93xNcYs0lRtnclf3t%2Fr2cAk6z5MyW%2F4levXh%2BMQI7OmuTpW584Po6aYzfC%2FD%2FKjHt9QGdCPtOuAOdhp4aeCVbCy%2FJ5YNj1j 4bpnWLD5eW7v%2BkE4LtQc4Oj1oA8atD8x10oJj8%2FP97Dw%2FmMrVO49zMrCbvB6bk4ti72koUrxAHBJR1sxXUEA7yKpvDuRor0s0lz1U778Ek7BHx6nZhTHHc70qCpCwSyOAlUEJdlWpSieCbUZ OscAHSbi5sa2WOu6a447RIZmKKUfUM3cxuNYMqpX6DcfrEYOfBkh8rsrTnDhfYp9fEdNRg75xcGGGtPknlAYBCGKLIxL9K9TaIszpcJ3qo6ghQuH8b2YDGjOw70pHCtw31x%2BEi8lDu97HiD6oOnj W5SFG2IZUi4YCgA4PbpOKgEm7wYRnYgf4qYDXg0TCf9Wcew9d%2FXZn42EI2iVGizOi4hZRQTk4wK2XQCsMRGNv6sh%2F42S7NdQEnFIzBptB%2BXFnd0dEndcyIoo%2BCl2d5t6u7p6UWaGwKyPlA fCHaudmtI2bBAiZD%2B1CrcirH4y2MGxPIqENifFvmiMkGml0sRflBscCDWdEbTHV%2Bm0kZAu47rbVZJbSNNbHb5v1Ybyfs8h7D3SpeXGTn%2BE%2B87%2Fdxfnw6WMpjSwHy2BCr4L8r45iIyZf5 797P5liFPzqOTDh6a2PN1i9KlHrAbyTFFhef0Kv%2F7jhu19fWh3YLavd6uVIb3n5P0ww6CMZZTOdKFzleOjTjsDurWqVuesVX8W1m4SLrGZO9q0p%2BXbu3MIPv68bMCvmm%2Fp3P5lQNNe8zZM7V 2yPSWRIRzCMO%2B%2FbtzklSI1Czx2aR6XYvzwfww%3D%3D&checksum=2023452976252a3aa7b5b09b4bd3871174cd91141f80

Maybe too late, but on a 2011 Dodge Journey I never saw more than 75° C even on twisty uphill driving with a LOT of Up-down-up... gearchanges...
That is on the Transmission Oil Temperature indicator.

ETA: And that wit 4 Adults and full summer vacation gear on board.

[Edited on 3/26/2019 by Angel Acevedo]

I think the mineral oil will be breaking down at 140 c

I’ll cut through this a bit.
Engines have magnetic sump plugs, simple magnets nothing exotic, unlikely the gearbox will get hotter than engine oil

Engine oil has a cooling system to help it though (and a filter, and a pump to keep it moving round!).