Electric battery Earn £175 per month from your EV!
BMW i3 wrapped in adverts

Gearbox oil change done

Great, thanks! Hopefully that’s just how they are then.

Just having mine done pick up car 2morrow

oh man, good i came across this to remind myself if anything else - This is on my TODO list.
point 1.

And spring is here, so no more excuses…

Anyone in London (north, west?) who wants to do the same, maybe we pair up on this joyful task?
My drive at home is at 3-5% gradient. so isn’t exactly helping there either…

pps - i take it we care about the spec of the oil, not the brand - about about this one (because i have not heard of millers, nor that i am a mechanic)

The spec is the most important part. The one that you have linked has the extreme pressure additive, and matches the coding; it will do the job.

Make sure you have a length of clean pipe to reach between the filler cap and the entry point in the cabin access point.

I changed my oil tonight, took me 33 minutes and 55 seconds :smiley:
The results are amazing, its so much quieter and smoother on the throttle, its amazing.
My Twizy is just over 3.5 years old and a little over 3k miles, and the oil was really black.

I need to do this!

Its worth it for peace of mind if nothing else.
Cost and effort is minimal.

Just had the gearbox oil changed and new rear pads fitted (supplied by myself). Total cost £75, including 2 litres of oil (75W/90). My Twizy has done just under 15K miles.
Have to say there is no obvious difference in smoothness or noise level, as some of you have experienced. But looking at the colour of the used oil, it probably was worth the effort.

2 Litres of Oil???
Where did the other 1 litre go? :grinning:


1 Like

It didn’t actually use the full 2 litres. There were some leakages while the mechanic was experimenting how to put the oil in. I have got the rest of the oil.

Renault Mechanic?
Learning by soiling, or what? :wink:

Takes about 1 year to get rid of the “cat urine” smell after Renault had done that to my first twizy.
(The changed the gearbox and filled about 1,2 Liters into the new one. 10km later the Twizy was leaking a puddle of oil onto the pavement)

Next time try it yourself.
Takes about a hour and isn´t that hard to do.


Wasn’t a Renault mechanic. I made him watched the YouTube video first. Tried to put the oil in through the overflow plug hole first but he didn’t have the pump to force the oil in, so it was taking forever. Eventually he put it in through the breather tube. It was quite a job to get at it because I didn’t want him to remove the rear seat.
Glad I wasn’t doing it as I am not mechanically minded at all and I haven’t got the tools.

You can also fill up the gearbox trough the inspection hole.(As seen in the video at 1:26)
But this can get messy. Wenn 1 Liter is insert it will overflow at this ispection opening.

But since you mechanic marinated the gearbox anyways this might be the better solution for the next time :wink:

I did my oil change this weekend on a 1 year old stock Twizy having driven 10.000km and I have to say it was about time. The old oil was as liquid as water and relatively dirty. I preferred lifting up the Twizy and removing the baseplate and doing everything from underneath instead of taking apart the interior to fill the gearbox from the top. In my opinion, that’s also how most gearboxes are in fact serviced. Just drained the transmission and filled it up with a siringhe through the the what they here call the inspection hole but what in my opinion was also designed as a filling hole since it also serves as a deterrent against overfilling the gearbox. In my case out came slightly less than 1l and in went 1l and it didn’t overflow. The Twizy feels smoother and is in fact a lot quieter. I used the oil as specified in the Comex spec sheet.


@bcv92 is right. This is the way gear boxes and transmissions are serviced. Drain the oil through the “draining hole” on the bottom of the gearbox (it’s a screw with a magnet on the tip of it to attract metallic wear debris - don’t forget to clean it) and then just fill in the oil through the “filling hole”. Don’t make it more complex than necessary! :wink: I was a car mechanic and when doing service on the gearbox (oil replacement or just refill), we always filled up oil until it started to overflow on the filling hole (always accessible from the bottom) - this is so to say the reference. By the way, after having refilled 1 liter of oil, you can take a curved Allen wrench and measure the oil level of the gearbox just below the filling hole by inserting the short part of the Allen wrench into the filling hole and then downwards - holding the longer part of the Allen wrench horizontally.

I did it yesterday on my Twizy (25’000km) by removing rear bumper and base plate, lifting the Twizy a little bit on the left/rear side with a small car jack to have better access (don’t forget to tight the hand break, to immobilize the front wheels and secure the lifted car).

I think it was a good thing to do it (Motorex Gear Oil Hypoid SAE 80W/90 GL-5) - the gearbox is a little bit smoother and quieter, which is just normal - but don’t expect having no more gearbox noise. :wink:

It’s easy to fill from inside the car though. Just remove the rear seat and there is a hole where you can insert a hose.

@Zuikkis, sure, I believe you… but since you need to remove the bottom plate anyway to properly drain the oil, it make also sense to fill via the filling hole providing a very easy access and visibility on what you do.

Well it’s been a few months after I changed mine, but I couldn’t figure out how you would fill it from the bottom. I guess you need some sort of syringe to push oil upwards? And also very small hose, the inspection bolt hole is quite small (8mm?). But certainly there is not enough room to fill it by simply pouring from the bottle.

The top fill plug can be removed by twisting with hand, no tools required. Then just remove seat and insert hose through the hole, and you can use funnel to pour the oil in. It does not take more than 5 seconds to have the hose in correct place, because as you said, there is good visibility.

You can see the hole in the video linked above, at 2:00 position… In the red circle the top filling plug, and shining above it the hole from inside the car.