joining the thread. My 2014 QX60 (122K miles) makes a louder than usual "whining" noise when accelerating (sounds like a manual shift that s running in a too low gear and needs to shift up). It drives smooth, just feels heavy and louder than usual. It s been going on for a couple of months, took it to 2 mechanics, no one seemed to find an issue. Got diagnostics done by Infinity yesterday ($240): they pulled out the transfer case plug and found burnt sludge, metal shavings and no fluid. There is no explanation why this happened. Possibly a leak, but I never found fluid. Recommendation is to replace the transfer case ($7K). It does not make sense to me to keep putting money in this car and think I should just trade it in and cut my losses (I already replaced shocks, struts, oil cover gaskets, front and side engine mount, catalytic converter, radiator, etc...). I've taken really good care of this car and did all the maintenance and replacements to date. I loved my QX60 but am super disappointed it did not hold up better and has such a low residual value at the end. I thought it would have lasted me much longer with less issues.
Update: I'm currently at a local shop with a mechanic I trust. He flushed the transfer case as good as he could and filled up the fluid. I ll keep an eye on the fluid but will be looking for a new ride soon.