Changing the gearbox oil on a 2CV

One of the items we didn’t get a chance to do during the first service was changing the gearbox oil.  This forms part of the D – or yearly – service.  As with any oil change you’ll want the engine to be nice and warm so the oil flows well.

2CV gearbox oil sump plug

Looking from the front of the car the gearbox sump plug is just visible behind the clutch.  Access is good as there’s a vee shaped cut out in the under-tray through which you can get a 21mm sump plug socket.

Vee shaped notch in the 2CV's under-tray giving access to the gearbox sump plug

There’s plenty of clearance here to get at the nut itself.

2CV gearbox sump plug

With a catch pan in place the sump plug can be unscrewed and the gearbox oil allowed to drain.  At this point it’s a good idea to remove the 21mm filler plug on the off side of the gearbox.

The sump plug has a magnetic core that catches the inevitable metal shavings that are created by the gears.  2CV garbox magnetic sump plug showing captured metal fragments

Removing these was proving a bit tricky but I found that transferring them to my magnetic pickup tool – which seems to have a stronger magnet – helped as that was easier to clean.

Once the oil has finished draining the sump plug can be refitted.  This is where the sump plug socket really comes into its own.  The nut sits on the cork with all the thread showing which makes it much easier to re-locate the plug in the sump.

Sump plug socket with sump plug

When re-fitting sump plugs it’s always worth using a fresh washer if possible.

With the sump now plugged you can re-fill the gearbox with new oil.  It will take 0.9 litres of 80W/85W gearbox oil which is added through the filler on the off side of the gearbox.  The oil normally comes in a can with a tube and access is good.  Before you start make sure you’ve put the catch pan under the gearbox.

Filling a 2CV gearbox with oil

(Rather a blurry photo as by this point I’d got oil on the lens.)

When the oil is just coming back out of the filler hole (hence the catch pan) then you’ve added enough and you can refit the filler plug, again with a new washer.