Peugeot 806 Gearbox Slipping

Sounds familiar. I had a similar issue with my 806, although it wasn't quite at that mileage. I noticed some gear grinding sounds before the slipping started. Have you checked the gear oil level recently?

Thanks for the response. No grinding yet, just the slipping. I haven't checked the gear oil level, to be honest. Is it easily accessible? And did checking/changing the oil help in your case?

On mine, it was more than just the oil level. The gear oil was contaminated with mechanical wear debris, indicating internal damage. While topping it off might give temporary relief, it's likely a sign of worse to come. I'd suggest taking it to a workshop to get it properly diagnosed.

Thanks, I appreciate the advice. Took it to a local workshop as you suggested. Turns out it was defective gears in the transfer case, causing the oil wear as suspected. Repair came out to 330€. Thanks again!