Ian_D

2010 R3 40k. Replaced gearbox oil with Redline MT90 at 15k. She's done a few track days, but these have involved 3rd & 4th, rarely 2nd, and I've always been careful to give the gears time to change.

My gearbox is unusually stiff & notchy when shifting into 1st & 2nd, particularly from cold. I now double declutch every time, but it remains very notchy.

Could this be an issue with the gearbox oil? Would changing to a different oil help?

NotAPreppie

Notchy or grindy?

If notchy when cold, change your gear oil and see what happens. Could just be the oil breaking down.

Ian_D

Thanks.

Notchy. No grinding. Today (outside temp 50F): 3rd was a little notchy, 2nd notchy and 1st not too bad.

I'm happy to change the oil, looking at the standard specification of GL-4 SAE 75W90, but probably won't be able to do it for a couple of weeks.

UnknownJinX

If you had a few track days then that might explain why the oil is breaking down.

You can experiment around different oil. Everyone except for me would recommend the Motorcraft XT-M5-QS. I personally had better luck with Motul Gear 300.

TeamRX8

iTrader: (25)

That’s just MT90 imo, which I generally try to discourage people here from using. Choose one of the two mentioned above. I never used Motul, but trust JinX recommendation for it. I never had any issue with Motorcraft like him either despite considerable time riding a 10k rev limiter for racing situations.

Ian_D

Thanks. I can't get hold of the Motorcraft near me, so the Motul Gear 300 it will be.

UnknownJinX

TBH I think I am the only person here that didn't like the Motorcraft so I might just be an outlier. It could be a bad batch or something.

Motul is good, but just like any other fluid, if you go tracking with it then it's recommended you change it sooner than a car that's not tracked.

Brettus

iTrader: (2)

If you don't have any luck with the Motul ...try this stuff . It might not be the best thing for g/box life on track but if your box is gone anyway ...... it will help with your issue .................. till it dies

https://www.rx8club.com/series-i-tec...-fluid-270351/

Also while i think of it ....if it's just first and second ...could it be misalignment of the shifter plate ?

Soravia

NC2/3 Miata uses same transmission. In cold Colorado winter, I put in GM Spec ACDelco fluid to keep the 1-2 shift going smoothly before it warms up.
GM fluids are very thin. I recommend ACDelco 10-4016 if you're in cold weather places. Mix half and half with Motorcraft XT-M5-QS if you are in between. If in hot climate, use XT-M5-QS

TeamRX8

iTrader: (25)

and every noob with their magic potion concoction is a qualified expert, if only life was so simple.

for some people being silly isn’t enough, they have to go out of their way and make it as inconvenient and complex as possible to be extra proud of doing such a good job at it.

wannawankel

Redline working well for me Summer and Winter - I used Redline MT-90 as a replacement around 40K miles and I've got about 19K on that same fluid. No issues.

mamdurer

I absolutely need to warm it up in cold Colorado winters or the gearbox will be very stiff into 1st and 2nd. A minute warming up in cold weather doesn't hurt engine longevity either.