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How hot does gearbox oil get??
cliftyhanger - 25/3/19 at 11:40 AM

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


watsonpj - 25/3/19 at 12:21 PM

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


watsonpj - 25/3/19 at 12:24 PM

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.


Mr Whippy - 25/3/19 at 12:35 PM

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


joneh - 25/3/19 at 12:46 PM

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.


cliftyhanger - 25/3/19 at 01:15 PM

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]


coyoteboy - 25/3/19 at 02:35 PM

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

Even on your GT4? I have! That's why they had the gearbox cooling duct in from the front of the bumper cover.


FatChapChipChop - 25/3/19 at 02:41 PM

quote:
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


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 !!


AdamR20 - 25/3/19 at 04:25 PM

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]


cliftyhanger - 25/3/19 at 04:52 PM

quote:
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 !!


I hadn't seen the BGH advice. It was a nice flat bit at the lowest part of the case, so that@s where I drilled. And now I know why it is flat.


On the other note, the magnet has been in the oven at 180 for a couple of hours as the lady of the house has been out. All good so I am happy to use the magnet I have.


steve m - 25/3/19 at 07:15 PM

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


Angel Acevedo - 26/3/19 at 12:37 PM

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]


Dingz - 27/3/19 at 09:50 PM

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


snapper - 28/3/19 at 11:04 PM

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


AdamR20 - 29/3/19 at 10:33 AM

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