transmission trouble

04 tacoma 4x4.pulling boat suddenly wont shift to second gear.automatic. rps go way up at 20mph.shut off motor suddenly everything worksfine.eight weeks later same thing happens.shut off motor several times with no improvement. Let sit for twenty minutes and alls good again.no problem now but afraid to pull boat.driving truck fifty miles daily with no more problems. any ideas? Is this a transmission problem or a sensor problem? Thanks

 

Change fluid and see if problem goes away. If not, take it to a transmission shop.

 

sounds like something is getting HOT...

 

I checked fluid level and it was good and looked good.the rpms shot up at twenty mph.the engine hadn't cooled down the first time it righted itself.i feel like somethings not telling the transmission to shift.it feels like a clutch slipping.this truck has never leaked fluids of any kind .all levels look good

 

I would be checking for codes . You have a computer controlled transmission . If the computer sees a problem with a solenoid or any sensor for that matter , it may not upshift .
input or output speed sensor or possibly a shift solenoid comes to mind
Got some info posted here that may help

http://www.tacomaworld.com/forum/te...warner-340-series-transmissions-write-up.html

 

Went to autozone today showed a transmission sensor code.going to shop tomorrow. Thanks for insights