Yes, I have. I hadn’t forgotten and was waiting until I’d done a few journeys so that I could give an accurate assessment. I now conclude that the gear change is better than before, especially when cold. Just to remind people the oil I used was Red Line MTL 75W-80 GL4. I’ve now moved on from thinking about gearbox oil and am just enjoying the car again, but at least I know what to get in the future.
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For an ND, this is the norm unfortunately. Nothing you have said raises a red flag to me.
Mine does seem to be worse with the Millers unfortunately.
It might be fairly normal but I’m sure the car wasn’t like this when I bought it. If it had been I would have taken it back. I certainly didn’t become too aware of it until after that 5th service.
For now I just compensate for it by adjusting my driving for the first few miles but I’m still not convinced it’s normal.
Awesome. Public service 
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My car is due in with my local guy on Monday for oil and filter plus a general look over. He has confirmed he has 75W/80 GL4 available but couldn’t confirm which brand. He says transmission fluid is usually lifetime (true of the diff according to Mazda I believe) but not necessarily true of the gearbox. He doesn’t get too many ‘enthusiast’ owners though but said he’d do the job if I am happy to pay.
I am slightly reserved as I am extremely happy with the performance of the shift but the car will be going in to its eighth year and the job should be sound preventative maintenance. In any case, I shall report back with what he uses and how I get on.
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I think the key thing to remember with the ND gearbox and differential is that they are known to run VERY hot, I think the gearbox casing especially doesn’t lean itself well to keeping cool. Regular oil changes and anything you can do to keep it cool are very much recommended, especially on a car enthusiastically driven.
Great so many forum users report back with their findings after changing. Helps others further down the line, ie, “If I have seen further, it is by standing on the shoulders of giants” ~ Issac Newton
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I was told a diff oil change is as important as an engine oil change, most especially if you are doing long distance motorway driving. That’s probably not the case with most of us, I do motorway driving if going on holiday mostly.
Anyways I’ve been changing mine every two years (diff) and gearbox say every three or 20k miles.
You don’t have to of course, I like as nice a clean oil as I can swirling around in the bits that it does.
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I want the diff done as well but have not been able to get my hands on the Mazda stuff and the main dealer quote was absolutely ludicrous.
I will get it done before next years big European trip one way or another. The car won’t have many long trips over the winter.
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Diff
I an in Northern Ireland unfortunately so unable to make use MX-5 Parts for fluid orders.
That’s a pity. Best of luck sourcing it.
I use Millers and the diff is a REALLY simple job (especially on a standard ride height car), can be done without a jack.
Put this in, always used it in my MX-5 diffs, under whatever guise it was before, GL4/5 spec. I’ve got some now to go in my ND1 diff.
Is this just the same stuff you use in the gearbox?
No, that above just the diff.
Now gearbox oil, well there are plenty of oil threads, some have been combined into one if you find them. One dedicated to the ND gear oils and engine oils you should be using. Opinions what’s correct what isn’t, what works what’s not so good rumble on. The oil that’s favoured ATM is 75w 80 or proper Mazda gear oil.
I’ve just bought some Castrol 75w 90 GL4 to use in mine, jury out whether it does the job, I can only report on that when it’s in. It’ll probably be a few weeks/months before I give it a go.
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Misread the 75W80 vs 90 on the bottle. I might try source a bottle of that over the weekend so my guy can do both on Monday.
Thank you.
Am I right in thinking that if the car drives fine once warmed up then there’s nothing physically wrong with the gearbox?
I did wonder if I had a problem with the 2nd gear synchro but after a few miles it shifts fine.
I’ll get it looked at when I’ve got more time but it’s a hassle as I’d need to drop the car off to be tested the next day. Otherwise once I’ve driven to the garage it’ll be behaving itself.
Seems to be the case. It seems some owners may just be more lucky than others if their 1st → 2nd cold shift is totally fine. Different techniques might come into play too. I ‘granny’ 1st to 2nd early doors. It’s a bit horses for courses- my up! gti 1sts to 2nds like butter from the off if it’s 20 degrees C or minus 2 degrees C. But then that effortless box might then have people saying it isn’t ‘mechanical’ enough etc etc
Sounds like mine, a little notchy when cold. It’s a bit deja vu with the ND, the only MX-5 I’ve owned which didn’t have a notchy when cold change 1st to 2nd was a NA 5 speed. One NB, two NC’s now the ND1 all 6 speeders and variable notchy 1st to 2nd changes when cold.
I can’t be that unlucky with these so I put it down to the way the box is. Magic potions (blended special oils) are available to stop this or to ease it, I live with it and have got use to it. I shall be changing oils soon,to what I’ve always used, see other threads/posts.