I had my transmission rebuilt back in 2008 and it seems like I might need another rebuild. A couple of questions:

1) what is the theory behind replacing the solenoids first to see if that fixes things?
2) which solenoid kit should I get the one for 1990-1999 Isuzu's, or 2000 and up Isuzu's?
3) where is the link to the company that was offering heavy duty rebuild kits?

Thanks for any input :-)

My tranny problems this time came all of a sudden on a road trip pulling a very light trailer. It made it 3.5 hours going 80mph all the way there with no problems, but then when I was coming back to Houston it would not shift out of 2nd gear and tranny light started flashing. I got on the highway and by turning the engine off while rolling in neutral going about 40mph I somehow got the tranny to shift up to 3rd and OD once and then set the cruise control and then the tranny would pulsate RPM's anytime it got close to needing to down shift. The downshifts were harder and more inconsistent then normal. I cleared the code from the computer while driving in OD and it did not come back until I slowed down and it shifted back down to first. I checked my transmission level the next time I drove it, and it was a little low. I topped it off and it did not help anything, it is still throwing the tranny code immediately and will not shift out of 2nd gear until it redlines and even then it normally just stays in 2nd. This time when I clear the code it comes back immediately. The code is not coming up as anything recognizable. Sometimes it just says "?" For the code. Regardless the VX is not drive-able at the moment. Should I try the solenoids? Or just get the HD rebuild kit and have it rebuilt or find that company that rebuilds them and buy a rebuilt on?