Hi All.
After being a long suffering L322 owner I've now gone supercharged RRS. Found a rad leaking so decided to pull the front end apart and remove it all. Had the rads checked and repaired but my question is what is the cooler in the middle of the main radiator. It's oil based but doesn't feel or smell like gearbox, but too clean to be engine oil. Can anyone help with advising what it is so I can top it once it's all back together.

Thanks in advance.

Do you mean in the side of the main radiator itself? If so, that's the transmission cooling circuit. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Inside yes, actually part of the main rad. Appears to be two rads in one, very clever. No joins just two pipes coming out that are clamped with jubilees. I thought it would be transmission but there's no distinctive smell to the oil.

Inside yes, actually part of the main rad. Appears to be two rads in one, very clever. No joins just two pipes coming out that are clamped with jubilees. I thought it would be transmission but there's no distinctive smell to the oil.

Gearbox oil cooler from thr sounds of it

Thanks guys, will be going to the dealers on the morning for a litre of whatever it is. Not a lot came out.
Have to say my rad on my l322 was a lot easier to come out than this one.