The shifter knob on my 2003 lincoln aviator broke off. the shifter was locked in place in drive and you are unable to shift into any other gear except the gear you're in. it seems that a very cheap plastic piece broke under the shifter knob and the dealer quoted me $1200 dollars to replace the entire shifter assembly. i have checked online and seen that this is a very-very common problem among owners. there is no recall for this issue, but this is surely a severe safety issue. i am not sure how many complaints it takes but this is a horrible safety issue. also, this vehicle has a whole array of front and rear differential issues along with a severe clunking noise when the vehicle is 1st put into reverse, drive or downshifts after acceleration. *tr