5 speed notchy shifting

dmad_dood · Postby **dmad_dood** » Sun Nov 16, 2014 9:21 pm

Hi there everyone my na8s done 103XXXkm and ive noticed the gearbox isn't as sweet as it used to be.. When i change from 1st to 2nd for the first time of the day there will be a little crunch but that will only happen for the first change of the day.

Then throughout the day i will have a bit of trouble going from 2nd to 3rd no crunch or anything it just will be a bit notchy and not very smooth.

Finally since i got the car, going from 3rd to 2nd there has always been a noticable notch-iness no matter how i change down rev matching or whatever.

For reference i'm really gentle on my drive line i don't slam it through gears i always feel my way through the box, i don't skip gears, i dont dump the clutch or ride it, i dont stamp on the throttle and i always rev match.

Thanks,

Jonathan.

chrons_rotary · Postby **chrons_rotary** » Sun Nov 16, 2014 10:19 pm

dmad_dood wrote:Hi there everyone my na8s done 103XXXkm and ive noticed the gearbox isn't as sweet as it used to be.. When i change from 1st to 2nd for the first time of the day there will be a little crunch but that will only happen for the first change of the day.

Then throughout the day i will have a bit of trouble going from 2nd to 3rd no crunch or anything it just will be a bit notchy and not very smooth.

Finally since i got the car, going from 3rd to 2nd there has always been a noticable notch-iness no matter how i change down rev matching or whatever.

For reference i'm really gentle on my drive line i don't slam it through gears i always feel my way through the box, i don't skip gears, i dont dump the clutch or ride it, i dont stamp on the throttle and i always rev match.

Thanks,

Jonathan.

What weight oil have you used in the box?

dmad_dood · Postby **dmad_dood** » Sun Nov 16, 2014 10:23 pm

Good question, i havent done gearbox oil since i got the car. Would fluids make the diifference?

speed · Postby **speed** » Mon Nov 17, 2014 10:43 am

Change the fluids. If still notchy use a telflon paste

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dmad_dood · Postby **dmad_dood** » Mon Nov 17, 2014 2:01 pm

What weight oil should I use? Does it differ with age or mileage? Thanks.

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speed · Postby **speed** » Mon Nov 17, 2014 5:23 pm

I'd just use what Mazda recommends. Ask your auto parts store and check the listing with your own eyes

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speed freak · Postby **speed freak** » Mon Nov 17, 2014 5:46 pm

Dont quote me but isnt it something like 75w-90?

Iv seen that Castrol and Nulon is popular. Could also add some of the G70 Nulon stuff too when you change the oil, heard it makes a good difference.

speed · Postby **speed** » Mon Nov 17, 2014 6:37 pm

I prefer castrol as far as oils go and suspect that g70 is a Teflon paste.
The paste alone would more than likely fix your issue but since you haven't changed the oil, I recommend you do that first

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dmad_dood · Postby **dmad_dood** » Mon Nov 17, 2014 8:59 pm

Defiantly worth a go and see what happens from there. The gearbox oil is probably several years old and i'm assuming its done a lot of k's aswell.

where do i drain and fill from?

Thanks for the help,

Jono.

YanMa YatTai · Postby **YanMa YatTai** » Mon Nov 17, 2014 9:44 pm

Do a search here and the big forum for how to details. The drain plug is a PITA and square 14mm if memory serves. Get a square or 12 point socket, else get something massive and grips that sucka. Be prepared for much swearing. Oh, and make sure you can remove the fill plug first before attempting the drain plug. Then work out how to send fluid in there - pump or via a tube using gravity.

YanMa YatTai · Postby **YanMa YatTai** » Tue Nov 18, 2014 7:53 am

Bolts other way around. Square is fill plug

chrons_rotary · Postby **chrons_rotary** » Tue Nov 18, 2014 10:40 pm

Refilled my gearbox today with 75w90 Nulon smooth shift oil.
Square fill plug wasnt too hard to get undone, just used a big shifter.
Borrowed a hand operated oil pump from work, easy as to fill, and i imagine alot easier than trying to sort out a gravity feed tube.
I do recommend putting in the teflon additive aswell (G70 Nulon?) just to make sure.
If it is still notchy after this, start looking for a good condition 2nd hand gearbox, or be prepared to get it rebuilt.

dmad_dood · Postby **dmad_dood** » Tue Nov 18, 2014 10:44 pm

Did u notice a difference in shifting. I also took a look under my car today and I think I found the plug. Looks like the oil sump just under the gearbox.

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chrons_rotary · Postby **chrons_rotary** » Tue Nov 18, 2014 10:53 pm

dmad_dood wrote:Did u notice a difference in shifting. I also took a look under my car today and I think I found the plug. Looks like the oil sump just under the gearbox.

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Well to tell you the truth, my original gearbox (NA8) ate 2 teeth on one of the gears last week, so i replaced it with a lower km NB8A 5 speed and replaced the oil in that.
It does feel better than the NA8 gearbox before it died, though it still doesnt feel as smooth as the box in my dads NB8A, but i think his has had an easy life before he bought it.