Hi guys, I got a 95, obd2, 343 trans, fzj80. 277k not account for the last 30k or so of bigger tires. Truck sat for about a month when I was doing some dailying and work on my vw. Had to jump the truck to get it to run, drove great 45 miles. Got off the freeway and felt like it was in second start, which I've hit on accident many times(my dog actually not me) got a code 753 shift solenoid. Was a little mad at it because I'd clear it and immediately back as soon as it failed a shift. Wouldn't go into second at all, kind of try then immediately click passed. So truck sat for a weekend and I fired it up again that Monday and it shifted fine no code. Drove it the next day and as soon as it warmed up bam won't do second again. Found a couple threads on it but there doesn't seem to be a ton of info on this problem. I put a shift solenoid in it didn't fix it so I put a new battery in it didn't fix it (definitely was having voltage issues from the old battery) found the one common thing was the plug so I got onto it and cleaned that good and checked the pins for being pulled out and corrosion, all good. Now before I throw a trans at this thing is there anything else I'm missing? Ps I have a shop and am very well accustomed to working on my vehicles obviously. My thought now is I got some seal issue or something going on inside the trans or valve body not holding pressure when the oil warms up. Not sure I don't work on the internals of transmissions. Any help much appreciated, still not convinced it isn't electrical since this all happened after it sat for a while and the battery died. Ran and shifted fine before
