Changing the gearbox oil on a Caterham (Mazda 5 speed)

IMPORTANT INFO - I'VE BEEN MADE AWARE THAT THE SMALL "DRAIN PLUG" ON THE SIDE OF THE GEARBOX IS NOT A DRAIN, APPARENTLY YOUR GEARBOX WILL NEED REBUILT IF YOU UNDO IT.
Another winter service job, changing replacing the oil on my gearbox. Caterham 2016 310S with a Mazda 5 speed box.

[@Faburisuh]

I recently changed the gearbox oil of my 165 with Suzuki engine & gearbox. The access to the filler plug is harder than on your 310. To fill it in, I used a bigger hose that I connected to a funnel. It allows to fill it very quickly.

[@ianfid]

Nice one and keep the videos coming. 👍🏻

[@StuartSutherland-1]

Thanks

[@RichardHaigh]

Box takes 1.6L in the main section and has 300ml in the gearstick section. You can suck the 300ml out and then get 1.9L in, but it's a lot of hassle. Better replacing the 1.6L more often :)

[@KrisFLton]

Just about to do the same to my Mazda box - with the same oil! Very helpful - I'd not yet found the forum posts... Can I just clarify your warning above about not undoing the small "drain plug" ? Assume that is the lower bolt on the side, not the square one accessed through the footwell - the one you didn't undo right? Thanks in advance!

[@StuartSutherland-1]

Correct. Apparently if you take it out something dislodges and you need to rebuild the box ☹️

[@KrisFLton]

@@StuartSutherland-1 Eek! Best not get that wrong then! Did the MTL oil improve things? Mine is quite stiff and notchy at times.

[@StuartSutherland-1]

@@KrisFLton my gearbox is 100 times slicker and faster to change gear at high revs now - but I’m pretty sure that’s the light flywheel I fitted at a similar time. For me it was just good to service the gear box.