4Runner gearbox slipping

Sounds familiar. I had a similar problem with my old Volvo XC70. The symptoms were almost identical. Have you noticed any gear grinding or oil leakage? Mechanical wear can do a number on those transfer cases.

Yeah, now that you mention it, I have noticed a bit of a grinding noise sometimes. Where did you end up finding the problem in your Volvo?

Turned out to be defective gears in the transfer case. It's like when you have worn out bicycle gears: jumping and just not catching right. I'd suggest getting it checked out by a workshop. It cost me around 330€ to fix the 4Runner. Better safe than sorry, especially with gear wear.

Thanks a lot for the advice! I'll take it to a shop and have them check the transfer case gears. Hopefully, it's a similar fix to yours. Appreciate the help!