Transmission issue?

10/23/2023 I got my transmission fluid changed @ 88k miles. Before I got it changed it was shifting hard going into 4th so I decided that it probably needed changed so I took it to Toyota and had them do it. They put 3 Gal of ATF in. The truck downshifts better and all that but idk if it’s always been there or because I don’t know how one drives with fresh fluid in it.. but I just noticed when I’m driving and get to about 4th gear then it shifts to 5th it lunges forward kinda like a push of momentum (throws my body forward a little)same thing for 5th going into 6th. Idk if it’s “normal” or not. Only performance mod I have on it is the KDmax tune. Maybe Toyota reset my transmission’s values? Is it because my transmission isn’t use to the new fluid yet? Or should I use this warranty I have? Or is it normal? Lol…. I know their transmissions are finicky at times and all that and I don’t see to many people have transmission issues. so idk just looking for some reassurance.

 

Hopefully they didn't put 3 gallons of fluid in the tranny!! The capacity is only about 10.7 qts dry and I doubt they drained the torque converter. That said, the KDMax tune changes the shift logic so there is a very high chance they will not warranty the transmission for shifting hard when you have changed the shifting characteristics of a stock trans. I have the KDMax tune on mine and I don't shift hard at all into 5th or...if I ever make it to...6th.

 

The accumulators are responsible for softening shifts. I doubt that is the issue though. More than likely, they got the fluid level wrong. I would get it rechecked.

 

It said on the service paper 3 Gallon. Idk if that was all used or what. I’m not worried about the tune. Simple enough to return it back to stock.

 

I’d be more concerned that they charged you and said they used 3 gallons when they should have used just under 4 quarts. So I would verify what they serviced in the transmission.

 

Chances are you got a fluid exchange (or flush). Which ever flushing machine they use requires 3-4 gallons of fluid to flush out the transmission and cooler lines. I recently got a fluid exchange and was charged for 4 gallons of WS fluid.