Notchy NC gearbox curiosity/history

Technical Area Engine, Transmission, Exhaust etc
2

Hi

Obviously read ton’s and suffer myself from the Notchy gear box 1st to 2nd,I can live with it and learnt how to change smoother,but did the NC have this problem when brand new from the garage if so why would you buy,and if not is there any owners out there that noticed when the problems started happening.  

3

My NC2 (bought new; 6-speed gearbox) has always been just a little bit notchy when cold, but always fine when warmed up.  It’s never been a problem for me - I just don’t try to rush the gearchange, pausing slightly in neutral between the gears, as I was taught to do by my driving instructor way back in 1982, always does the trick.

Then when it’s warmed through there’s no notchiness & quick shifts from 1st to 2nd aren’t a problem.

Gearbox oil’s been changed twice so far - 3 years old, 15,000 miles & 6 years old, 28,000 miles.

4

Have owned 2 NC’s from new, one MK3 and one MK3.5. 

Both were notchy changing 1st to 2nd when cold and were fine once warmed up. As other have mentioned just take it easy on the gear change until the oil is up to temperature. 

 

Interestingly its the same as above on my Toyota GT86.

5

Well it’s good to know that from new these cars where notchy, but i’m suprised that Mazda couldn’t rectify the problem it’s not like in 2006 and beyond we had to accept such things.

I’ve had a few new cars since 2006 and none have ever had an underlying trait that could potentially scare purchases off, which I would think would have scared me off back in the day spending 20K.  

6

My thoughts too.  But I’m used to it, and as others have found it is perfectly OK once well warmed up.

When I drove the NDs I was impressed by how smooth the gear changes were, but then as demonstrators they had probably already been warmed up by someone earlier. 

However the gear change on my 2015/16 Mazda3 is slick and fast (2012/13 design) at any temperature, and the clutch operating point is in the right place midway on the pedal travel too.

7

Do we not have any owners with no difficulties.

8

My NC 3.75 has always been a bit notchy when  cold, just like others who’ve posted. I bought it with 8k on the clock.

i am actually a little relieved to hear it’s  (probably) a general trait, rather than just in my car.

 

9

Guess the majority of us had made our mind up on the MX 5 , so no matter what niggles it had we were buying an MX 5. But if it was my everyday car I wouldn’t have bought a car with a notchy gearbox 

10

It was the same on my 1998 1.8is Mk1, 2000 1.8is Mk2, my 2003 1.8 Montana, 2006 Mk3 and my 2015 Mk3.75. I think they’re all the same. The recalcitrant 1st to 2nd change on a Ferrari when cold doesn’t stop people buying them if they can afford one.

11

I owned a Mk2 imported RS with the 6 speed. First job was to change the shift boots, gear and diff oils. It made a big difference to the gear change but still notchy from cold, as others have found that’s the 6 speed trait, just adjust your gear change to suit it.

12

Proud to be member of the “Notchy Club”  2012 NC sport tech PRHT.

I put it down to the car having a bit of character and quite enjoy giving a talk to anyone that I lend the car to about its little quirks and warming it up and testing the brakes for pull and power.

13

Im in the garage trade 

trust me loads of different makes and models of vehicles have notchy gear changes when cold 

its just one of those things especially in the winter months 

it never bothers me as a rule as i never drive a vehicle with any zest when cold anyway i always give them time to warm up 

14

Makes sense.  ‘Notchiness’ will be exacerbated by using more force behind the movement of the lever and making a faster change.  Gentle sustained force on the lever allows a momentary pause in neutral and lets the layshaft speed drop a bit more which means there’s less for the synchro to do, so less resistance.

It’s usually 1st to 2nd that’s the ‘problem’ because (looks at gear table for 2011 MX5 - see below) for a given road speed the engine (and therefore the layshaft) has to lose 50% of its rpm on changing from 1st to 2nd, much more than the differences between higher gears.

That’s my theory anyway. I’m no expert, I just try to drive as smoothly as possible.  I can certainly create notchiness by making that 1>2 change too quickly, but I don’t get it when I slow it down a bit. 

Another factor in the feel might be that the MX5 gear change is very direct - typical front-wheel-drive cars have a remote gear change involving cables and levers at the gearbox end so the feel is more cushioned. 

Changes in rpm from gear to gear:

1st to 2nd  -50%

2nd to 3rd  -36%

3rd to 4th  -24%

4th to 5th  -22%

5th to 6th  -17%

 

15

Thanks guys for coming back with your comments. Normally all you get is mines fine so at least we are suffering together.

16

Is this a problem peculiar to the six speed box or does the five speed box also suffer? My 57 plate Icon has a five speed box and I don’t seem to notice a huge problem

17

Think it’s more a six speed issue but then again with owning a six speed I only ever read on six speed issues.

18

It’s in the buyer guide for 6 speed only, so 5 speed doesn’t appear to have this additional “character” (yes my 6sp 2012 PRFT has it, diff and gearbox oil being done this week along with the underseal treatment at MX5 restorer so will report if makes any difference), and as others have said I get the temps up before any spirited driving so no great hindrance to me anyway.

 

19

Does the engine temperature have an effect on the gearbox warming quicker.

20

I think that it does exist on the 5-speed box as well. At least it does on my Mk3.5 PRHT (2010 and bog standard apart from bling) which I would describe as ‘notchy’ going from 1st to 2nd gear. By this I mean that there is a sort of step half way so you can’t snatch it through in one movement but have to make an almost imperceptible pause halfway through the change pulling it from 1st and squeezing it into 2nd. It is a technique quickly learned and I certainly have never regarded it as either a problem or a fault. For me it is just a characteristic and I would even describe it as quite satisfying to feel it slipping neatly into gear. In no way has it ever detracted from the enjoyment I get driving my MX-5.

PS. No difference between hot or cold by the way.