Gearbox Tunnel hot to touch?

Not sure it’s related but ever since I took my NB to a track day the gearbox tunnel feels strangely warm (as hot as a mug of tea when I touch the surface).

Should I be worried?

Is the gearbox due an oil change? Or low (I can’t see any leaks from below, but it may already be low?)

Mines been like that since I had it if you do long runs in it, never been an issue other than makes cabin very hot especially if you have hard top on. If it’s happening over short runs could be exhaust blowing hot gasses onto underside of tunnel. (Fitted air con to mine to get over cabin temp issue)

Check the rubber gear gaiters :sunglasses:probably perished :astonished:
New available from mx5parts or other specialists


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I’ll go with what Bally says above, they’ll get very warm on track days too I guess.

Thanks all.

Will take a look. But is the theory behind it being the gaitors that the heat leaks out from this and even to the side of the tunnel (where I can feel most of the heat)?

Is it worth at all draining and refilling the oil from the turret? Mines a 6speed.

You won’t have turret oil in the NB 6 speed box, 5 speed yes👍
Most definitely check the gaiters, a good chance they are perished, they all need replacing at some point.
Plus the fact the exhaust runs right under the tunnel area so there will be some heat coming in under the console anyway.

Perished gators will let heat in. The exhaust also runs down there and possible it is too close to something.
They do get hot though, try racing one with no insulation!

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Hi @Maverick1111,

As the other guys have said check the gaiters, I had the exact same issue and mine were toast, replaced them and the heat is much lower. Also, as an amazing side effect, the car cabin is also now much quieter!

While you’re in there, extract the old turret oil and replenish it with new, and you will find 1st and 2nd less clunky to change into (only needs like 80-100ml).

I would usually agree to the turret oil change, but the OP doesn’t have it in his. :+1:

oops, my bad sorry missed that.

Thanks for all the tips!

Given my six speed doesn’t have turret oil, will it help changing the gearbox oil after checking/replacing the gaitor (in terms of shift feel?)

Likely yes.
Castrol 75W/90 GL4 is fine.
BUT make sure you can undo the refill nut before the drain nut and make sure you do not confuse the drain nut with the one that will allow selector forks to go walkies.
How to change gearbox oil writeup - Mazda-Menders

Apparently there’s a write up of how to change the gearshift boot on this forum’s thread but no amount of search attempts is bringing it up. Would anyone know where it resides?

If you type in to Google something like Mazda MX-5 NB gear shift boot/gaiter change you will come across all manner of links on the subject. Best ones are the videos on YouTube, some are US made videos for the Miata NB but are very much the same, even the Mk1 NA is the same procedure just differs on how you remove the centre console.

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