I’m looking for technical help or recommendations on: Gearbox Issues
Hi all, I purchased my first MX5 a few months back. From my research and testing driving of other ND’s of the same spec, I came to understand that the gearbox in these cars can be quite notchy/clunky when cold.
However, I’ve noticed that second gear has become increasingly more difficult to select over the past few weeks. The issue is particularly noticeable when cold, and improves ever so slightly after a few miles when some heat has built up in the gearbox. It isn’t slick by any means. Reverse and 1st gear are also not too pleasant to select most of the time.
I don’t know if the dealer I bought the car from changed the gearbox oil before I bought it, so my first instinct is to get that done. Would this help?
I’ve come to understand that these particular model of 2.0 ND (late 2015/2016) are susceptible to gearbox trouble. Mine was registered in January 2016.
I have an RAC used car warranty from the dealer for another 9 months. The car was back in their garage last week for an air con issue that was resolved. I made them aware of the gearbox issue when I was dropping it off. They said they checked it and couldn’t fault the gearbox.
Anyone got any ideas? Any advice on what steps to take next?
Worth getting the gearbox oil changed as the first point of call. Ford gearbox oil XT-M5-QS has an excellent reputation and may ease the symptoms you are experiencing or Mazda oil if you can get it. However the gearboxes are variable in build quality but a change in oil should help. Also check when the brake fluid was changed as the clutch fluid should have been done at the same time.
It is a bit of a characteristic of MX-5 gearboxes particularly noticeable as the weather gets colder. Failures are rare and you will know if it was that as you’re likely to lose a gear and have some bad noise…
As suggested take care to warm up, the specific oil used in the gearbox can make a surprising difference too, currently I’m running the Millers listed below to very satisfactory results.
I’m using Motul Gear 300 75w/90 and very happy with it. Very occasionally (once or twice a year) I might get cold start selection difficulty with first and second gears but it disappears within a mile of driving.
Ok I think the first thing to do is to get the gearbox oil changed. Is there much difference between Mazda Oil and aftermarket brands. Millers, Motul etc?
I’ll be sending the car to Mazda for a service soon and was thinking of getting them to change it. I would do it myself only I don’t have the facilities right now. Currently on street parking.
Mazda gearbox oil does have its fair share of critics in some circles but I found it to give the best and smoothest performance of the few that I’ve tried. The trouble is, I can’t find anywhere that has it available, so it’s onto the next stage and for me the Motul grade comes in a very close second.
It grieves me a bit because I sell oil for a living and I had to pay full retail price for the Motul. My various suppliers told me to use their “fix all” gearbox oil, but these and other well known brands just don’t do the job; you will get gear selection issues with a number of them. (None of the offending brands are mentioned above).
Mazda are not the only manufacturer with such issues; some Kia models have the same problem and I’m sure others do too. If your gearbox oil has been changed, do you know what went in?
Following on from the above. I went ahead and changed the gearbox oil. Millers Motorsport CRX 75w90 NT+.
Problem has surprisingly gotten worse. Now when cold, 2nd gear has become at times near impossible to select. Often requires going back to neutral and then trying to go into 2nd again. Very stiff going between 1st and 2nd. It’s as if the car is holding onto 1st at times when trying to get to 2nd.
No grinding however. 3rd gear can also be a bit an unpleasant clunk.
Problem eases significantly after 15-20 mins when the gearbox is warm but it isn’t perfect.
I’ve done more research and asked around and I’ve come to learn that this oil may be too thick … especially in the cold conditions we are having lately?
Interested to here if anyone else has had this issue. What steps would you take? Would you recommend an alternative gear oil?
I think you need a GL-4 spec oil in these. If it’s anything like the 6 speed NC gearbox only to GL-4 spec 75w 90 oil.
That oil IanH mentioned is just that, your oil is also to GL-5 spec, don’t think they like that flavour.
Millers oil finder suggests, all 75W-90:
EE Performance MTF
XF Premium MTF
Trident Professional MTF
It’s not obvious why any of those should be any better than what you have used but it might be worth giving Miller’s technical a call. They have been helpful to me in the past.
Frankly I don’t know what the dealer put in mine. But it is also ‘stiffer’ than before it was changed, to the point of being obstructive when cold if rushed.
Thanks Martin. I finally got your oil blend put into my gearbox yesterday and noticed an immediate improvement. 1st - 2nd and 3rd - 2nd is transformed! I would highly recommend this product (along with new Diff Oil for good measures).
Redline MT90 (75W90) is often recommended for this. It’s supposed to have the right level of friction to allow the synchro cones to do their job. It made a small difference to my NA but I wouldn’t say it was transformative. Mazda gearboxes all seem to be a bit baulky when cold, even the latest SkyActiv-MT.
