Nissan Repair: 90 maxima auto transmission, cottman transmissions, nissan maxima

Question
My 90 Nissan Maxima v6 3.0l shifts smoothly through the 1st and 2nd gear, but when I accelerate the rpsm raise to 3,000 to 4,000 and the 3rd gear does not catch.  Somebody told me it could be the solenoids, is that the problem?  If it could be, where are they located and how do I go about replacing them?

Answer
Hi Alberto,

I assume the check engine light is on? Either way, it seems you are in fail safe as the computer is protecting the transmission against further damage. This will give you a 1-2 shift and reverse only. Solenoid and speed sensor problems need to be identified by a transmission specialist and are located inside the transmission. Do not waste your time with a general repair shop. Cottman Transmissions will diagnose your car for free if you have one in the area.