Lots of oil seals on a 306 need to know which one
use the dipstick
probably 10W40
5w40
10w40 is fine
The gearbox oil fill plug can be located, in your Peugeot 306 2.0, on the top of the gearbox nears the back. The plug can be removed with a three-quarter inch socket
4 quarts
Under the engine, towards the back of the sump.
with filter 3,7 without filter 3,2
I suggest you open the bonnet and look at the front of the engine below the exhaust manifold, it's very easy to see.
on the side of gearbox at top a remove ns wheel to see it its an 8mm hexagen shaped bolt
To change the oil on a Peugeot 306, first, warm up the engine to thin the oil, then turn it off and allow it to cool slightly. Place a drain pan under the oil pan, remove the drain plug, and let the old oil fully drain out. Replace the drain plug, remove the old oil filter using an oil filter wrench, and install a new one with a bit of oil on the gasket. Finally, refill the engine with the appropriate type and amount of new oil through the oil filler cap.
Several things could cause an oil leak in a 206 Peugeot including a bad cylinder head or a problem with a pulley oil seal. There could also be an issue with the rocker cover gasket.