Transmission Shock

jrh10 · March 14, 2003

Hi

I have an IS300 that goes into 2nd gear with an almighty thump that jerks the whole car - it does not happen everytime but perhaps 50% of the time. It makes it uncomfortable to drive and passengers can even feel it.

My dealer is reprogramming my engine management system this weeked with new settings that are supposed to eliminate what Lexus call "transmission shock"

Has any one else suffered this problem?

Jon

Veece · March 14, 2003

My IS200 which I have only had for about three weeks, has a very bad 1st to 2nd gear change (could just be me ), It makes a really bad clunking sound, as if I have just hammered the gear in without using the clutch (which one is the clutch again :duh: ), This happens about 75% of the time.

I will probably mention it when I finally get around to visiting my local dealer, I'm kind of waiting until my wheels start getting a bit worse, so I can get a warranty job on them.

UKPulse · March 14, 2003

A month or so ago I drove an 1yr old IS300 SportCross for a while and gear changes were fine - no jolt. Same with my current IS300, but then I've only covered about 250 miles in it.

So what does this re-programming of the ECU actually do? Is it masking some underlying mechanical problem, and why does this only happen on some '300s? Or maybe they all get like that after a while? . I'm hoping this isn't a problem I have to look forward to

/edited

agalbraith · March 15, 2003

The gear change on my IS300 is *marginally* jerky for a couple of minutes while the engine warms up. After that, it's incredibly smooth.

How old is your car? If it's a software fault, there'll be other cars made at the same time with the same problem. However, it's entirely reasonable that a software change will solve the problem.

Is there any pattern to the 50% of the time when it jerks? (i.e. engine speed, accelerator position, engine temperature, loading (ascend/descend).

Alistair