Seat Mii Gearbox Troubles

I also have a Seat Mii. I had similar gearbox issues recently. Slipping and unclean shifts are a pain. Have you checked the transfer fluid level? Maybe an oil change could help?

Thanks for the quick reply! When you had the problem, was it gradual, or did it happen suddenly? And did changing the gear oil completely fix it, or were there other issues?

For me, it was gradual. The oil change helped temporarily, but the slipping came back. Turned out there were defective gears in the transfer case. I'd suggest getting it checked at a workshop.

The workshop confirmed the transfer case oil wear fault, like you said. There's damage to some internal gears. Repair is estimated at 330€. Thanks for the heads up, you saved me diagnostic time!