Car Jerks When Pressing Gas Pedal While Moving In 2nd Or 3rd Gear

[vv1981]

I've searched the forum and someone mentioned flex couplings, but their problem was during shifting... for me there is a noticable jerk whenever i just touch the gas pedal while the car is moving and is probably in 2nd or 3rd gear. probably 3rd. the stronger i press on the gas pedal the bigger the jerk. There is no jerk while moving slow in 1st and its very smooth in 1st.

There is also a noticable jerk while shifting from Drive to Reverse or back into Drive. However, no jerk while shifting from Park into Drive.

I guess the transmission is starting to go? this has been occuring since i got the car with 200 000km. it has 223 000 now and the condition is the same, unchanged, not worse or better. The car is a 1997 LS400.

any ideas as to what i need to look into, or what this can be attributed to?

Thanks to all for your help.