Nissan Repair: Nissan 2.7 Turbo diesel transmission problem, shift problem, transmission shop

Question
I have a 1994 2.7 turbo diesel with auto transmission that has started jumping between the top two gears.  No problem in the lower gears but if you are cruising along at say 40 mph, it can't seem to decide which gear to stay in.  At times it will drop down a gear and run at high revs until you back off on the throttle.  Other times it will drop down a gear and then immediatley change back up. I have had the transmission flushed and oil replaced and this seemed to make the problem worse, but again not affecting the lower gears.

Answer
Iain,

THe problem could be that the clutches are slipping in the top two gears or that the overdrive sensor is defective.  That would cause 4th to 3rd down and upshifting.  You probably need the codes read to get a good understanding of what the transmission is sensing to cause the shift problem.  I would run the codes on the transmission and see what, if any are set.  A good transmission shop can check the pressures to see if the top two gears are leaking with a pressure gauge.  My bet is that the clutches are worn and the transmission needs to be refreched with new ones.