Strangely the standard glovebox manuals for mk2 Sprinters are largely devoid of any useful data in the fluids department. I am very used to going to a page in the handout that just tells you what you need. MB apparently feel the need to hide everything.
Looking into gearbox oil changes on a manual gearbox I’ve been told you need ~1.8L of oil and loads of people recommend genuine MB oil (MB part number A001 989 26 03 10). MB themselves stated the gearbox is apparently “sealed for life” however the oil really should be changed at least once every ten years! For third party oils it needs to comply with MB 235.10. I’m aiming to grab some of this from ECP: Febi Bilstein Transmission Oil (21829 Manual Transmission Fluid GL4 SAE 75W). There’s a great guide to changing the oil out on Sprinter Source.
Differentials oil on a 2005 Sprinter should comply with MB 235.0 and should be synthetic 75W90, you need 2-3 quarts for a differential.. I am aiming for TRIPLE QX Fully Synthetic 75w-90 LS – 5Ltr from the local EuroCarParts. Whilst doing a bit of research on the differentials I came across this great article which covers the whole process nicely: https://sprinter-camper.com/rear-differential-oil-change/