87 auto trans problem

[carnut]

I have an 87 V6 Pathfinder with auto trans. Recently when cold, I had to manual shift if for a few miles until I built up some heat in the motor and trans, then if shifted normally. This has been going on for about a month now, then today I noticed it wouldn't shift into 2nd and 3rd (3 speed) until I get off the gas and almost let it idle into the next gear. Driving up a steep hill it would down shift into 2nd but wouldn't engage 3rd when enough speed was built up until I backed off the gas but then there would be very little power to climb the hill in 3rd.

After reading the cheesy Chilton manual, I suspect the modulator or vacuum line (if there is one, I couldn't see squat from the engine compartment, too many things in the way). I'll just crawl under it at a later date to see if any vacuum lines are going down to the trans.

Anyone familiar with this setup? It is a 4 wheel drive with auto hubs. Thanks in advance for any possible help!

[carnut]

Well, I tinkered with it for awhile, the vacuum modulator is buried in the maze of cross members and has a metal line from the intake manifold to the trans. On the same vacuum tee on the manifold is a mickey mouse setup for the cruise control, a skinny plastic sleeve that goes into another plastic union to a vacuum hose with one end having a larger diameter hole than the other(this is the second Nissan that I've found a hose like this, hence why I won't ever buy another Nissan again!)

I finally took it to a tranny shop that rebuilt my Camaro auto many years ago and they reported that the torque convertor is shot, hence missed shifts, etc. and also the case is worn out. They are going to have a machine shop try to sleeve it, or it's time for a new case. The trans shop also stated that Japanese cars have the weakest transmissions of all vehicles and that they rebuild a lot of Japanese trannys.