I rencently had a problem with my super reliable 1985 Nissan Maxima. I drove somewhere with no problem, but when I left, the (automatic) transmission would not shift out of first to second gear no matter where the shifter was set. It slips some when set to D (drive), but not really when set to 1st. It has been that way ever since. The history of the transmission is as follows: I bought the car @ about 80k miles. All has been well. I flushed the transmission with Mobil 1 synthetic ATF at 155k. Now at about 162k things are broken. For this particular problem, the service manual says the following are possible causes in order of probability:

1. Control cable2. Throttle wire3. Oil quality4. Control valve5. Govenor valve6. Band brake7. Oil passage leak

I've checked and adjusted items 1 and 2 with no success. I checked the fluid level carefully for item 3. It is not burned or particularly dirty after 7k miles and synthetic ATF. Items 4-7 require some significant disassembly. I am probably capable of the following items if needed:

A. Have transmission professionally flushed.B. Replacing the valve body with a remanufactured unit.C. Inspect and replace governor shaft assembly.

As these items all require some significant time and/or money, is there one I should try first or is it most likely a failure in the clutches/brakes that I won't want to mess with? Is it time to dump the reliable Maxima? Any suggestions or experience is welcomed. Th

I would lean towards it being the valve body. But the problem is you just never know until you get in to it.