Nissan Repair: Transmission Question, nissan maxima, costly repair

Question
I was driving my 1996 Nissan Maxima down the road and tried passing a car by dropping the automatic transmission down a gear (doing about 35mph). When I dropped it down I heard a snap and now the car will not move. It runs great, but nothing will engage. Even when in park it will coast backward. What part snapped and is this a costly repair?

Answer
Mark,

Either the shift selector in the transmission has failed or the shifter linkage has popped off.  Get the car on a lift and remove the transmission pan and look where the shifter connects to the transmission and then on the inside.  I have seen both a broken linkage and the shift selector inside broken before.  The tell here is the car will not stay in park.  That leads me to think the shifter or linkage is broken.