MX-5 OC Forum

I am sure that when Mazda brought the "prototype" Mk3 to the National Rally at Goodwood in 2005, the guy (from Germany I believe) said that the six-speed box was the same one used in the Mazda 6.

Hopefully Roadster Robbie, AT or somebody else with much more technical knowledge than me can confirm.

Rich M:

 

CambsMaz:

How does one get the console off - where is this "screw" you mention.  Is it at either end of the console - under the "grab handle" under the heated switch or at the back? Thnaks.

Hi,

You only need the long centre part off,

from drivers position,

remove gearknob by twisting anticlock ..... 

Thanks for that.  Box oil was changed at the weekend and seems a lot smoother so will put this on the list of jobs to do.  I just know I will break something!

Not the same box as Mazda6 no, maybe the same manufacturer. I think the NC has carbon syncro rings or something. I'll dig out my training manual and confirm.

Edit...

The carbon syncro rings are on the NC facelift not the NC. Text below from the NC facelift training manual

The 6-speed MT is the P66M-D that has already been used for the predecessor. Compared to the previous P66M-D however, it has the following new features:

–The cones of the 1st to 4th gear synchronizer rings are partially plated with carbon for higher durability and smoother shift feel.

–The diameter of the 3rd and 4th synchronizer rings have been enlarged (6 mm) for easier synchronization at high engine speeds.

 Hmm, so they've fixed the parts that weren't a problem...

Geoff Walton.au:

Thanks Rich

I'm totally out of touch with the Mk3, it's nice to add to the knowledge bank. The Mk2 6 speed has a totally diferent remote arrangement which shares the main gearbox oil

Hi Geoff, yes I was surprised with how little specific info there is about the Mk3 NC on this forum  Perhaps you will add my console removal post to the faq and we can build some useful stuff.

Rich M:

Hi Geoff, yes I was surprised with how little specific info there is about the Mk3 NC on this forum  Perhaps you will add my console removal post to the faq and we can build some useful stuff.

I guess it's because the bulk of the faq was written before the Mk3 became old enough for owners to get into DIY and problems started to occur which aren't covered by warranty. So I agree with you that we need to get more stuff on the Mk3 into the FAQ, I've copied your text and will knock soething out soon, did you take any pics by any chance?

Geoff Walton.au:

Rich M:

Hi Geoff, yes I was surprised with how little specific info there is about the Mk3 NC on this forum  Perhaps you will add my console removal post to the faq and we can build some useful stuff.

I guess it's because the bulk of the faq was written before the Mk3 became old enough for owners to get into DIY and problems started to occur which aren't covered by warranty. So I agree with you that we need to get more stuff on the Mk3 into the FAQ, I've copied your text and will knock soething out soon, did you take any pics by any chance?

Yes a separate Mk3 faq section would be good. No pics this time I'm afraid, I did think about it but it was freezing and I'd wasted half an hour trying to remember how that window switch connector came out... I did make up a few new swear words if you're interested... perhaps not

CambsMaz:

   

Thanks for that.  Box oil was changed at the weekend and seems a lot smoother so will put this on the list of jobs to do.  I just know I will break something!

No probs, I needed to write it down for next time  It would be useful to know which oil you used.

There are photos of MK2 centre console removal in the How To guide for fitting the MX-5 parts centre storage tray, which has been in Soft Top Hardtop (August 2010) but not yet put on the forum, I'll do it ASAP. I have photos of an NC facelift for a future guide.

 Is this the same for Mk 3.5's 6 speed.    Mine seems a bit stiff in the lower gears untill it warms up, then its ok

Rich M:

CambsMaz:

   

Thanks for that.  Box oil was changed at the weekend and seems a lot smoother so will put this on the list of jobs to do.  I just know I will break something!

   

No probs, I needed to write it down for next time  It would be useful to know which oil you used.

Used Castrol Syntrans 75W90 GL4

-H-:

 Is this the same for Mk 3.5's 6 speed.    Mine seems a bit stiff in the lower gears untill it warms up, then its ok

I would have said so yes. Robbie detailed the changes for your box above but they look like minor tweaks for the advertising machine as the box is good once warm and the higher gears are already fine hot and cold. The cold shifting difficulty is a known issue and we see Mazda were not brave enough to claim, "new synchromesh hub design for perfect shifting under cold conditions". That should be the norm by now, certainly our Mazda 2 and 6 are both fine even in freezing conditions. 

CambsMaz:

  

Used Castrol Syntrans 75W90 GL4  

ok thanks

Just to bring this up again and perhaps get some expert help form you guys. I have a 2010 sport obviously with the revised six speeder. The car is 18 months old with 13.5k miles on it. Over the past couple of thousand miles some of the gearshifts have been a bit less precise than they have been. First to second being stiff when cold is pretty much a given (I also has a 2007 sport so am familiar with the six speed box) however, second up to third almost feels as if it baulks a little then there is a small almost crunch and in it goes, if hammering on a quick shift from second to third can often end in tears, coming down the box fifth to fourth sometimes sticks and is less that precise. This was not the case with my 2007 six speed, the box in it was a peach.

Now, I head off down south the week after next and whilst I have no concerns that the box is going to do anything silly but I have provisionaly booked the car into the dealer to have a look but my gut tells me they will come away with the usual line..... well sir that's just a characteristic of the box, which whilst in part may be the case for the sticky 1-2 when cold, is certainly not the case for the other niggles.

I'm tempted just to drain the box and re-fill with RedLine MT90 75W90 and see how that goes but, as I recall, certainly on the Mk2/2.5, you had to make sure you undid the right plug or it would result in a very expensive clunk as the selector for fifth and reverse iirc falls to the bottom of the box, best avoided eh!

Can anyone tell me if the setup for drain and re-fill plugs is the same on the Mk3/3.5 and also perhaps comment on the little 'niggles' I am experiencing?

TIA

 The Mk3/3.5 6 speed box is different to the Mk2/2.5 so don't worry about that warning faq about losing the selector.

The filler is also on the vehicle left (UK passenger) left and easy to access on a ramp with just one cover off. Filler and drain are both large hex nuts 24mm or 15/16 AF so you won't have a problem there at all. Do have an oil gun/syringe available, dead easy with one and very difficult without.

Consider doing the diff too for what it takes but remember you'll need GL5 oil there.

I thought about Redline for the gearbox but couldn't decide between MTL and MT90 as I feel it's definitely a cold/thick oil problem and MT90 is quite viscous. Checking a few data sheets I went with the Castrol Syntrans fully synth 75W90 GL4 which meets spec and is quite light. A bonus was I could get it at Halfords easily. Anyway this oil described my cold shift problem exactly on the label and has been as good as it says in sorting it out. I'd already tried Mobil synth 75W90 in there and it was even worse than the original oil (whatever that was) so I'm convinced the oil plays a great part in this problem. Since then all I can say is no problem at all now, great box, very positive, a tiny bit sluggish for the first few shifts then superb.   

Rich M:

 The Mk3/3.5 6 speed box is different to the Mk2/2.5 so don't worry about that warning faq about losing the selector.

The filler is also on the vehicle left (UK passenger) left and easy to access on a ramp with just one cover off. Filler and drain are both large hex nuts 24mm or 15/16 AF so you won't have a problem there at all. Do have an oil gun/syringe available, dead easy with one and very difficult without.

Consider doing the diff too for what it takes but remember you'll need GL5 oil there.

I thought about Redline for the gearbox but couldn't decide between MTL and MT90 as I feel it's definitely a cold/thick oil problem and MT90 is quite viscous. Checking a few data sheets I went with the Castrol Syntrans fully synth 75W90 GL4 which meets spec and is quite light. A bonus was I could get it at Halfords easily. Anyway this oil described my cold shift problem exactly on the label and has been as good as it says in sorting it out. I'd already tried Mobil synth 75W90 in there and it was even worse than the original oil (whatever that was) so I'm convinced the oil plays a great part in this problem. Since then all I can say is no problem at all now, great box, very positive, a tiny bit sluggish for the first few shifts then superb.   

Hi Rich and thanks for your pretty comprehensive answer.

TBH I think I'll be getting my friendly geometry guy to do this for me, he has done servicing on our Focus to a high standard and I'm simply not up to crawling aroung under cars either with or without a syringe anymore. Unfortunately not an old age thing but a seriously knackered back.

As far as oil choices,a lot of chat about various oils on different forums. I was certainly of the understanding that the Red Line MT90 75W90 was almost considered the "fix" for the first into second issue on earlier Mk3 'boxes 2006-2009. What concerns me is that my issues seem to go past this but as I say, I'm concerned that the dealer will almost certainly give me the "but they all do that sir, it's a characteristic of the car" which as we know is simply unacceptable. Yes the 1st to 2nd is well documented but my issues as far as I know aren't but I'd like to try a change of oil before I push the dealer further.

I assume that this is the oil you mean? May well give it a go, what's to lose and it certainly is handy that halfords stock it. It's just a bugger that the box requires 2.1 litres therefore three packs required probably get away with two litres as I'm pretty certain that a drain down will leave some residual oil enough that the two litres will do the job.