Transmission flush DIY

[b57]

I'm not seeing any DIYs so I'm assuming its a straightforward drain and fill. For those who've done it, anything to keep in mind?

[S4Bennett]

I think the wrench to loosen the fill bolt was tight to the front axle. I’d make sure you can loosen the fill bolt before draining the fluid. ECS Tuning Magnetic Drain Plug is a good upgrade to monitor wear. Drain is a M22 crush washer and I don’t remember the fill.

[ven0m]

Perform the fluid change on both the trans and rear diff while you're at it. Trans requires API GL-4 gear-oil (due to the syncro-mesh), diff requires API GL-5 (due to higher friction loads). Best choice for example is MotulGear 75w90 API GL-4/5. As it covers both criteria and adds the GL-5 strong friction resistance characteristics to the gearbox.

The draining and filling is straight forward:
- lift the car absolutely level
- open fill plug (Hex 10 or 12 key)
- open drain plug (Hex 10 or 12 key)
- catch as much oil as possible (recommended)
- close the drain plug (no crush washers present)
- fill up the transmission/diff 2mm up until the fill hole (+/- 1mm)
- close fill plug (same as drain plug, no crush washers)
- grab a beer