02J, 02K and 02M 5- and 6- speed boxes have combined fill-and-level plugs. The car MUST be on a level piece of ground and not jacked up or the level indication will be wrong. Inspection pit or service lift is ideal - you can see this is meant to be done at a dealer, can't you? However, don't some DIY servicing places exist where you can rent a bay with a pit???
Gearbox ident: Gearbox code letters are on the data label in the boot. Mine looks like this:
Code:
G131 24-1 591210 EG Type
VSS ZZZ 1M Z 2B987654 Chassis number 2B987654
1M28 24 1M2=Toledo 28 24 is the complete model code
TOLEDO TDI 8 SIGNA
81 MNO C5M 81 KW = engine power
ASV EGS Engine code and Transmission code
LS5N ---- ---- KU Paint No and interior
Gearbox type and date code (three letters, five digits) stamped on top of casing; on my EGS box it's on the clutch housing flange next to the gearbox, forward of the plastic plug that seals the timing mark vision port into the clutch casing.
Fill/level plug
02J, 02M: front face of the gearbox,a hex-socket plug
02K: end of the gearbox casing towards the rear, a hex-socket plug.
To top up, (the SEAT way) fill so that oil is just dripping out, replace plug, jack up front, run engine for 2 mins with a gear selected, drop, open plug and top up again.
Oil spec
You have to know the gearbox code, as this will tell you what oil it was filled with at the factory. The types of oil (synthetic vs non-synth) used in SEAT boxes should not be mixed as they will degrade each other
Yours should be an 02K (DUW or FSQ) requiring 1.7 litres of API GL4 SAE 75W (Hypoid).
Transmission oil level is a check item on the 20,000 mile service.