I am looking to gain some insight from you all about my transmission. The car has about 135k miles and I recently performed a filter and fluid change, as well as two drain and fills, as part of a (mainly) preventive maintenance measure. The only issue the transmission had was a slight flutter when shifting between 2nd and 3rd.

Since I changed the fluid, the shift from 2nd and 3rd became a bit different. Now when it shifts between the two, if I keep the throttle in the same position, the engine speed stays where it is and the transmission seems to hesitate getting into 3rd for about 3 seconds, the engine speed finally decreases, and unless I let off the throttle, it slams into third. If I let off the throttle, it seems to shift just fine and I can continue to accelerate. The problem is non-existent until the car is warmed to operating temperature... that's when the issue is noticeable.

Things to note:
I used Toyota T-IV fluid only.
Fluid is at proper level (about 2mm above HOT mark when at operating temp)

Could it be a dirty valve body? Did the new fluid detergent break away some sludge and it's clogging somewhere?

Any ideas or suggestions are appreciated. Thank you all.

 

I have the same problem. When it first occurred to me is when my trac off n check engine light came on. It kept slipping on the 2nd and 3rd too. So I had my mechanic who is a master tech at Toyota flush my tranny fluid 2 times. It was a real dark brown which means the owners before me may have not changed it in a long while or may have not changed it all. Once that happened the fluid turned back to its color which should always be red. That's how you can tell your tranny fluid is clean. But also when he check for my check engine light and trac off light came on it registered as my tranny going bad. 1st option was, I could replace my whole transmission or it said I could get by with changing my cylnoids. That would be my suggestion is to see if you can change those first before last resort of getting a whole new transmission. Also my gaskets were kind of leaking to so that I will have to replace in the near future. Hope I helped and have a great one.