- Engine Models this resource applies to
- BRM Engine
In this document, VW claims the reason for the special drain and fill procedure on the 0A4 family 5 speeds (Mk5 and newer MQ250 5 speed, which is an evolution of the 02J and 02A before it) is because the whole drivetrain is mounted more upright than they are on older generations, which might be plausible, but the real main reason is a change in the casting of the bellhousing.
The bellhousing has added a piece of casting from the underside of where the pinion shaft bearing plate bolts to the bellhousing to where the case magnet lives at the very bottom of the case, greatly reducing how effective oil drains into the differential region of the case. This is why you MUST remove the lower shift pin to get as much oil out of the transmission as just removing the normal drain plug does on the 02J/02A MQ250 gearboxes.
Once more, since the drainage is so poor into the differential region, you now must not use the fill plug to get the correct amount of oil in the transmission, but you should fill from a higher point than that with the exact specified amount.
On 0A4 5 speeds, this means 1.9 to 2 quarts being filled from either the reverse light switch hole, or just removing the entire shift tower and filling from there.
For 02S 6 speeds, which use 0A4 case halves but have an extended back cover to accommodate the extra gear, it should be closer to 2.2 quarts.
The bellhousing has added a piece of casting from the underside of where the pinion shaft bearing plate bolts to the bellhousing to where the case magnet lives at the very bottom of the case, greatly reducing how effective oil drains into the differential region of the case. This is why you MUST remove the lower shift pin to get as much oil out of the transmission as just removing the normal drain plug does on the 02J/02A MQ250 gearboxes.
Once more, since the drainage is so poor into the differential region, you now must not use the fill plug to get the correct amount of oil in the transmission, but you should fill from a higher point than that with the exact specified amount.
On 0A4 5 speeds, this means 1.9 to 2 quarts being filled from either the reverse light switch hole, or just removing the entire shift tower and filling from there.
For 02S 6 speeds, which use 0A4 case halves but have an extended back cover to accommodate the extra gear, it should be closer to 2.2 quarts.
- Body styles this resource applies to
- MKV (Golf, Jetta, NB)