Hello, folks,
 I'm trying to get some possible reasons why my 96 Saturn SL2 won't go into
reverse when the engine is warm.  If I put it in reverse right after I start
it, it'll back up, but if the engine has had time to warm up, it doesn't move.
It's like it's in neutral.  The car also shifts a kind of hard.  
 I've checked the automatic transmission fluid, and it has enough, and the
fluid isn't burnt.  I had a Grand Am that did the same thing, but never figured
out why.  The thing is, with the much lighter Grand Am, I could just put a foot
out the door an push the car backwards.  Saturns weigh more, though, so I can't
push it as easily.
 The car has about 145,000 miles on it, and it's always had a shifting hiccup
accellarating between 35 and 45 miles per hour, at least for the 8 months I've
had it.  But now, this new issue, and the "Service Engine Soon" light it on
 What might be the problem?  Could it be something simple/cheap, or am I
looking at $800 worth of transaxle repair?  I'm not sure the car is worth that
much, but I still owe a little more than that on it.
 Any ideas or advice on this would be greatly appreciated.  Thanks for any
help,
 Tedrick