Toyota Repair: drivability problems., output shaft, drivability problems

Question
hello,I own a 91 4 runner that has a speedometer that goes crazy on occasions and lately when it does,the car seems to pop in neutral.No power,i pull over put in park and back into drive,sometimes works.the trans oil and filter was changed and still acting up.Could the speed sensor be bad?is this an easy fix.THANKS

Answer
Possibly the speed sensor, it's relatively easy to replace, it's on the transmission tailshaft housing and has one 12mm bolt on it. Is the check engine light on? Normally the speed sensor doesn't cause the transmission to into neutral or seem to do so, the transmission may be slipping which would be another concern since the slipping of the clutches will cause the output shaft to stop rotating, the speed sensor receives it's revolution signal from this output shaft.