Nissan Repair: transmission, lint free rags, dextron iii

Question
I have a 92 Sentra, manual, that has recently started having what I assume is a problem with the trans.  When accelerating quickly or climbing a hill, the engine rpm's increase as if the car were out of gear or it's trying to down shift like an automatic.  Clutch going out?

Answer
It sounds like the clutches in your transmission are going out.  But, you could have a clogged filter screen.  Many of the late model transmissions have a polyester filter screen and when the fluid gets old it gums up the works.  Before I would drop the money for a new transmission I would change the filter and fluid.  It should only take four quarts to change what you can get to.  There is much more fluid in the torque converter and lines.  But, for the purpose of getting the filter clean, to see if that is the problem, all you need to do is change the filter and fluid.   Buy a filter kit that includes a gasket, filter and buy four quarts of Dextron II or Dextron III.  Be sure that you keep things clean and use lint free rags and never use any kind of sealant on the gasket.  Tighten the pan back up to just hand tight.  You will see the gasket squeezing so do not over do it or you will get a leak.  ALso, tighten cross ways and work back and forth until all the bolts are tight.  Put in the fluid and start the car.  Then, after you get to operating temperature check the fluid.  You do not want it too high or the fluid will foam and cause air bubbles in the fluid.  Too low and the transmission will suck air into the system and that is not good either.  At idle, in part, at operating temperature, on a flat, level surface is where you want to be when you check the fluid.  Also, pull the stick and wipe it off and then reinsert and withdraw to get an accurate reading.