Mini Paceman Gearbox Slipping

I have encountered similar issues. Gearbox slippage can sometimes indicate a transfer case issue, particularly given the mileage. Have you checked for any transfer fluid leaks around the unit?

Thank you for the information. I will inspect for oil leakage. If there are no visible leaks, could the defective gears still be the problem? What would cause the gear grinding noise even without oil leakage?

Yes, even without apparent transfer case oil leakage, defective gears could still be the root cause. Internal mechanical wear can occur over time regardless. The 'gear grinding' noise you mentioned may be a telltale sign of this. I would advise having a workshop inspect it to confirm.

I appreciate your insight. I took your advice and had it inspected. As suspected, there was significant mechanical wear within the transfer case. The transfer case oil showed evidence of particles, and the gears were indeed defective. Repair including parts and labor came to approximately 330€. Thank you again for your help.