Anyone having any issues with the drive train in a GLK350? I'm the original owner and started having issues with the vehicle at 49K when MB had to fix a leak on the transfer case. (This in addition to trying to fix a valve cover leak three times) since that time I started noticing a whining sound which is getting louder. Several mechanics indicated it may be a bearing in the transfer case. Now, at 84K, they are telling me I need a new transmission, transfer case and torque converter at $6000+. Of course, its not covered by the original 50K warranty. does this sound reasonable? ps I'm the original lessee and purchased it off of lease at 65K.