Sometimes when I really get on it, the transmission shifts down or jerks hard on the Bonnie. It'* been doing this for quite some time and the car has over 60k miles. I haven't changed the fluid or filter (?) yet, probably should - is there any other ideas what may be causing this, other than a rebuild? Possibly a Tech Service Bulletin? Thanks.
Yes this is in the 2001 SSEi. The hard shifting doesn't occur all the time - sometimes between first and second gear (or second and third?) - it jerks the car during moderate to hard accelerations. It doesn't do this during normal everyday driving. Sometimes it does it more when the car is cold or being warmed up than when it is hot.
I haven't put any additives in the transmission.
I may take it to the local transmission shop to change the fluid and filter - could it be starving transmission fluid through the filter if plugged (?)
There is a TSB regarding the 4t65E-HD transaxle regarding the valve body which may be the symptom your experiencing. I don't know the extent of the it but it involves drilling either a hole or enlarging an existing hole in the valve body. Common symptom is hard shifts out of the blue.