Hey, have a 2018 IS300 RWD with the 8 Speed trans. When ever the trans downshifts from 8th to 7th gear it always thumps really hard to the point i can feel in the drivers seat. It does it whether the car is in drive or if Im in manual mode and downshift with the paddles. Does it both ways, but in manual mode if I let off the throttle, downshift and then get back on it, its perfectly fine. It only does this from 8th to 7th gear downshift, every other downshift and upshift is fine. This normal??

 

no. are you still under warranty?

 

I agree with davyjordi, this is not normal. I would take it to the dealer ASAP. Especially if it's only the 8th-to-7th downshift.