if ANY work has been carried out on your front suspension, it is possible that the drive shaft will have popped out with consequent loss of oil. Mechanics will poke the drive shafts back in and say nothing because it takes additional time to drain and refill the box.
When I drained one of my cars (green), almost 2 litres came out. However the second one (silver) drained just half a litre and the third (yellow) one just over one litre.
Oil capacity: Gearbox drained: 2.0 litre (sources vary between 1.8 and 2.5 litres)
Oil quality: ESSO 75W80 EZL 848 or TOTAL 75W80 H 6965 - best bought from a Peugeot dealer
Oil level check: No checking of oil level (*)
Lubrication interval: Lubricated for life - I really worry when I read this! though we are told: (*) The sealing should be visually checked at each engine oil change interval.
Some garages can inject a specific amount of oil from underneath via the filler plug, or for home use, the gearbox can be refilled via the air vent hole on top.
Although there are various warnings, I found that changing the gearbox oil is quite straightforward. This is partly because there are no obstructions near the drain hole or fill hole as there are on other models which use the same gearbox.
You will need an 8mm square male drain plug tool - and a good socket spanner as the drain plug was in very tight. Jack the front passenger side (UK) high and support with an axle stand. Turn the steering hard left to make more room.
Loosen and remove the drain plug; drain the oil - the oil will come out horizontally initially so use a large bowl to collect the oil unless you want to lubricate your drive. When it has drained (I lowered the jack to ensure all the oil came out) - replace the drain plug and tighten.
the gearbox drain plug area looks oily because I had accidentally pulled the drive shafts out of the gearbox when changing the front suspension parts - this was where the oil ran down!
If at home, remove the air filter assembly.
To refill the gearbox takes 2.0 litres of Peugeot-supplied oil (see top of page) It fills through the gearbox breather hole - pull off the black plastic cap and the vent pipe is clearly visible.
I used an old rubber water pipe (inside diameter = ¾" = 19mm) which is self-supporting and fitted snugly over the breather pipe. I pushed a funnel into the end and it was a matter of a minute or so to fill the box. Don't fill too fast as the escaping air has to come back up the pipe and may splatter a bit - don't ask how I discovered this!
Remove the pipe, click the breather cover back into place and refit the air filter housing. Simples!
(1) input shaft. (2) release bearing guide. (3) clutch bell housing. (4) gearbox casing. (5) intermediate plate. (6) Bearing retainer (bearing retaining plate). (7) driving gear (5th gear). (8) secondary shaft. (9) synchroniser (5th gear). (10) driven gear (5th gear). (11) driven gear (4th gear). (12) 3rd/4th synchroniser. (13) driven gear (3rd gear). (14) driven gear (2nd gear). (15) 1st/2nd synchroniser and reverse driven gear. (16) driven gear (1st gear). (17) differential crown wheel. (18) satellite pinions. (19) planet wheels. (20) speedometer drive gear. (21) speedometer pinion. (22) differential housing.
is on top of the gearbox - access after removing the air filter assembly.
The original needs a long 22mm socket to remove. The replacement (shown) needed a more easy to find long 19mm socket.
Note: there are apparently TWO different reverse light switches: the one for 1.6 diesel gearboxes (2257.59) is shorter, 20mm measured from contact surface to end of moving tip - fitted to the BE4-5L gearbox.
The one for petrol (2257.53) is about 10mm longer - fitted to the MA gearbox on all the other models.