Volvo Repair: 850 volvo transmission, volvo transmission, transmission unit

Question
In driving in traffic I noticed some slippage went to turn around and no reverse it was as if I was in N nutural.  97 wagon with 173K. I was in the E mode and switched to the S mode. Everything was normal and I made it back to my house.  Then I put it in E and the transmission acting up switch back to s and every thing was OK. What do you think?
Thak you for you time and consideration.  Paul

Answer
you will need transmission unit you can rebuild it but i don't recommend that you rebuild just replace it with used one or new i can ship you new one for around $3000   or i can get you used transmission with 1 year labor and parts warranty  for $1800  im in chicago  i can send you transmission  to your location  but there in not much that you can do than just to replace it  the engine on the car will go over 300000 miles if you do oil changes on time if you like the car it is worth fixing/replacing  the transmission