05 Tacoma Sr5 Hard down shift

I have a tacoma 4.0 4x4 with 236k on it, A couple weeks ago i developed a hard down shift at lower speed. I took it to the shop right away and they checked for codes. Nothing was detected there. Then they wanted to pull the pan and they did and they said the fluid was clean no debris. They reinstalled it and refilled it. IT still has the hard down shift. I talked with another mechanic that thought it may be speed sensors? Just seeing if anyone else has had problems like this??

 

anyone????

 

Best thing is to start with the basic info. You say theres 236k on the clock...when is the last time you did any service on the fluid? And if you've ever changed or flushed it, what specific fluid is in it?

 

They are thinking it is a valve issue or a solenoid....