danny m wrote
i brought genuine vag stuff not cheap just under £50 for three bottles think it takes 2.3l?? part number G 052 171 A2 double check this is right oil for your car.
It really does depend on precisely which gearbox you have.
I copied this from another poster last year; it gives the OEM oil for six-speed boxes
"Quantity 2.6litres
Gearbox codes DRP / FMP / FHA / FHT / FEK / FEL / FGT / FGV / FZM / FZP / FMQ / EFF / ERF / FMH
Use Gear synthetic oil API GL4 SAE 75W in accordance with standard TL 521 71 (Spare no. G 052 171 A2)
Gearbox codes DRV / EFY / EUK
Use Gear oil API GL4 SAE 75W 90 in accordance with standard TL 521 57 (high performance synthetic oil)"
The Seat manual states
"* There is a new type of mineral gear oil API GL4 SAE 75W (Hypoid) in accordance with TL 726 /Y. This type of oil can onlybe used in gearboxes where it has been specified and must never be used in gearboxes that incorporate the previous oil API GL4 SAE 75W90 (Synthetic, high performance).
* Due to the incompatibility between these types of oils, they must never be mixed as the change the properties of the lubricant."
I read that as saying that contamination of either oil with the other will degrade it dangerously, even if you drain the gearbox. In fact it is difficult to drain a gearbox completely, there will be puddles of the old oil left trapped behind support webs and in the bearings.
For my car (TDI 110 Toledo) I could have EBF or EGS boxes: EBF uses synthetic oil, EGS the later mineral oil: otherwise they are identical, same ratios, same outer casing. I suppose its possible that the bearings might be different to take account of the different oil, but I'd be surprised if that were so.