Gearbox oil change

[PMB]

If you go under the car on your back from the front, pass the radiator, keep going past the gearbox, is the drain plug at the rear or side?

[PMB]

Sorry about the repeated questions, i sent it 4x times.

[Steve Walsh]

Number 15 in this pic.

I can get my car up on the lift later today and take pictures if you are still struggling

[PMB]

Steve, drain plug found, just need a hand made tool now to remove. Thank you for your help.

[Steve Walsh]

Well done, Good luck with catching the oil when it comes out, I probably caught about 70 percent of mine, the rest I mopped up later

[PMB]

Gearbox oil changed today. Steve many thanks for your help.
I caught 90% of the oil but what a mess on the subframe.
The plug was so hard to remove, I bet its the original oil looking at the colour of it.

[Steve Walsh]

Good to hear you had success


Steve

[pi14]

Dear Colleagues,

I wanted to change the gearbox oil in my C5 (X7), year 2017. I have manual gearbox type ML6C. But I could not locate the drain plug.
Fortunately, I found your conversation in this forum. I have some photos of the gearbox which I attached. I would much appreciate if you could confirm if I properly identified this plug. As you said, if this is the plug I need to do the tool since there is so little room...

Best,
Przemek

[GiveMeABreak]

Drain Plug

Quantity to refill DW Engine - after draining
Gearbox casing with fins: 1.9L
Gearbox casing without fins: 2.6L

[pi14]

Thank you Marc for the sketch.
I have already seen it but the plug is located in a place which is difficult to reach. It looks like designers did not want to have users to change the oil without taking the gearbox out. That is why I am asking for the confirmation if I am right.
Przemek

[GiveMeABreak]

It drains from the (1) in the picture, but requires the undershield protection to be removed to get to. It's filled from the top:

[pi14]

Thank you once again!
Przemek

[pi14]

Finally I changed the oil after 158000km (I am the seconed owner and I do not think that someone changed the oil before). I will summarize it, maybe someone find it useful.
First, I prepared the tool (see the photo). It was done from the square (8mm) rod, bent in 90 degree. The height is approx. 3.5 cm since there is limited space.
I drained the oil with help of the plastic bottle to make less mess.
It came out more than 1.9l of oil. It was black and looked liked the used engine oil (see the photo).
The drain plug is magnetic and there was a lot of metallic debris on it.
There is a copper washer 16x22-2.
I put 2l of the fresh oil.
I have no problems with the gearbox but I can fill the gears can be shifted more smoothly now.
However, looking on the color of the used oil and those debris, I think that changing this oil was a good decision even it is a little bit problematic and it should not be changed according to the service.

[MattBLancs]

]

Those are interesting pictures, I wondered why the 2.0 might be so different than my own 2.2 HDi!

But I think the difference isn't engine size - instead it is subframe differences. Mine has the aluminium subframe and it is much less in the way than yours which looks like a steel subframe! How odd they should differ so much!

I'll take a comparison picture next time I'm under mine with the undertray out the way to show the difference.

[pi14]

Yes, it is steel subframe.
Maybe this construction is only in the BlueHDI version of this engine, since when I started to look in the web how to change oil in the manual gearbox the setup was a little bit different. I mean, there were no collision to get the drain plug. This is only my guessing since I am not the mechanician