emix

Hello, and thank you for your answer. Yes the Lexus dealer local to me, said they only replace the transmission. However I've taken it to a service specialized in gearboxes, they suggested it might be the valve block but they need to remove the transmission and check it themselves to be sure. There are no fault codes, which makes it really hard to pinpoint the problem.

Hello everyone, I'm new here, sadly my first post is about an issue I'm having witih my beloved 2004 SC430. I'll detail the problem below as the techs at my local dealer can't seem to suggest anything but gearbox replacement, I'm hoping to find a cheaper solution for my troubles. So it started happening a few months ago. When shifting from 4th to 5th gear the car jerks, the higher the rpm the harder it jerks, it kind of lunges forward for a moment. This stuff becomes quite violent at high speed. It also sometimes does it from 3rd to 4th. It only happens after the car is warmed up, never when cold. At first I changed the gearbox oil and filter, and indeed shifts are smoother but the problem hasn't gone away. Has anyone had similar problems that could me some advice on what was wrong? My car has only 90k kms, it's been in the family since it was new, nothing ever happened to it, and was always well maintained.