My 94 850 has 74,000 miles and was recently serviced (10,000 miles ago) including tranny flush/service. yesterday I went to back out of the driveway, the back up lights came on but the tranny didn't engage, after checking the fluid which was in good shape (red and slippery), I tried it again, finally after revving the motor up to around 2500 rpm the tranny engaged but roughly then disengaged again. I tried cycling the shifter lever 30 times or so but it still doesn't work right. the only gear position that I get any response in is 3, or D but even then the tranny feels like it's slipping and once I let off the gas it comes to an immediate stop kind of like the e brake is on (which we never use). I cringe at the thought of taking it to a mechanic (would have to tow it). any ideas????