NC 2.0 6 Speed gearbox.
Are these 2 oils okay to go with?
Is the Castrol Syntrans Multivehicle 75W-90 the stuff to go for the gearbox
No idea for those. Sure someone else will.
I use Total Transmission Dual 9FE 75W 90 Manual Gearbox Oil.
Recommended by Total and safe for the soft metals used in the box too.
Used for both diff and gearbox.
If it helps 
Yep both perfect for the NC. The universal diff oil should be for GL-5 which it is.
The 6 speeds take a tad over 2ltrs so buy X 3 bottles for that, 1 bottle will do the diff in that oil type👍
I am trying to reduce the notchy shifts between 1st and 2nd gear in the 6 speed box, always good to have other options, so thanks.
Perfect 
I had mine changed by Roddisons in Sheffield, they mentioned to check the temperature range of the oils if you are doing track days. The standard oil has quite a low temp range and can degrade if it gets too hot. They know their stuff and have had temp sensors fitted.
I think standard oil is fine for road use.
However it was quite cheap to get them to do it.
1 Like
Ask 10 people about gearbox oil and you’ll get 10 different answers.
You’ll only need 2ltrs unless you’re throwing it on the floor.
We do one which eliminates the cold change issue.
What you will find is that nobody will agree on any one other oil apart from ours. For every person that says XYZ works for them you’ll get people who say it didn’t for them.
I have never heard from anyone (who tried it) say ours didn’t work. You’ll get people who haven’t tried it saying it doesn’t work 
This what you’re up against with human nature.
I was recently approached by a chap on a FB thread who said he had the Syntrans stuff in and his cold changes were terrible, I found it to be no good when cold too, same as any other. I said as you’re a random FB character would you like to do a test whilst the weather is cold and report back on here? He said he could and reported back on FB last night to say his changes had greatly improved straight away.
1 Like
Sounds good this stuff but my mechanic wont fit unknown oils as he can’t guarantee the work. So went for the Castrol stuff and will see. Turret is dry so might be part of the problem.
Yes if that’s dry it won’t be helping, but it wouldn’t change from hot to cold though.
2.1ltr for the 6 speed gearbox. I had to buy an extra bottle to complete the fill.
I know the manual says 2.1, but i’ve never been able to get that in.
In real life terms .1L is neither here nor there when you think about it.
I will be taking my 2014 Sport Recaro to Roddisons for its bi-annual gearbox & diff oil
changes once Covid restrictions are over. Hopefully at the same time as the next
Roddisons Tech Evening.
I am not sure what gear oil Paul uses but it works & works well even in the recent minus zero temperatures.
Just resurrecting this old thread on gearbox oils and cold shifts. I’ve just been reading a thread about gear oils for the ND and it seems even though the manual says 75W-90 the cars actually come with 75W-80 and that is what Mazda dealers themselves use. Was just wondering if this same theory could also work for NC boxes to help cold shifts?
Just to confirm I’ve got an NC 6 speed and am about to change the gearbox oil. I currently have no cold shift problems at all so the last thing I want to do is change the oil and give myself a problem I didn’t have before!
On a recommendation, I changed from Total to Castrol and have no regrets whatsoever.
No cold shift issues with mine.
Stick with the GL4 only.
NC 3.75 6 speed box.
Thanks, yes I was planning on using the Castrol I just thought this was an interesting theory. I think I’m a bit paranoid about introducing a problem I don’t already have! 
I did when I first changed it to Total.
Then back to normal good box with the Castrol.
Thanks that’s good to know, I’m sure I’ll end up using the Castrol