Here's a weird one; I just bought a lovely Dark green (C) 4 cyl. 1994 900S 86,000 miles, convertible with a possible transmission curse. It seems that most of the time, though most notably when the car is warm, Reverse does not catch. When you move from Park to reverse there's no clunk, or reduction of idle speed associated with an autotrans engaging. The transmission works in Neutral and Drive etc. The second time this happened, ( the first time I stuck my foot out the door and pushed Fred Flinstone Style)I put it in park as the car was rolling very slightly. That seemed to have jarred something; reverse would then engage , though it was now a bit sluggish going into drive. I've been able to reproduce this at will. I showed it to my girlfriend and she used that trick once, only she said that afterwards the car would not engage in Drive. I checked the fuild and found it to be red, I rolled some betwen my fingers and it felt fine - no metal shavings etc. This car has had this issue in the past. the previous owner had the Bands adjusted which he said solved it. 'Til now. It's stumped anyone I've spoken to. I'm hoping someone out there might have been through something like this and lived to tell about it...
judd