Jerk/jolt/clunk when coming to a stop
 

Hello everyone! First off, I'm new to the forums and have already benefited quite a bit from reading through all the GS threads. Thanks to all the members of the forum for your feedback, advise, etc.

I am the new owner of a 2007 Lexus GS350 and I absolutely love the car. 70k miles and it has been well taken care of by the previous two owners. The question I have is regarding a strange subtle jerk when coming to a stop. This seems to be the most intense with a medium force stop but I can also feel it when coasting to a stop. It happens frequently and sometimes is less harsh than other times. I noticed it right after picking up the vehicle but I didn't really pay much attention. After driving the car for 2 months I notice it more. The jerk seems to be happening during downshifting and is at about 15 mph every time. It's not extreme but passengers typically notice it if I point it out. Then they can feel it every time it happens. The other shifts are smooth including accelerating and so forth.

I've read a few threads that mention it could be a normal downshift feature of the vehicle. I'm taking the car into the shop (not the stealership) to have the problem looked at in the next few days. I wanted to post to not only get feedback here but to also post a followup on what the shop comes up with. If it's a normal characteristic of the car then I'm ok with that. But I'm concerned there is a bigger issue.

I reset the ECU (pulled the ETC and EFI2 Fuses) about two weeks ago but haven't noticed a difference in shifting.

Any input would be greatly appreciated.

The World Standard fluid transmissions have no dipstick so it is possible that it was serviced and it is overfull. I would check the fluid level first because an overfilled trans. can cause harsh shifting.
I checked and found no TSB's for harsh shift.

THAT in particular is not normal, you were probably reading a local thread on someone hitting the "S" shift function. That is normal, as the downshift it gives him a slight jerk... no jerkiness. When you say downshift, are the brakes applied? It sounds like your brakes are in the equation and I would start diagnosis there.

Either way GL and keep us followed up OP!

Thanks, I'll definitely have that checked out if I can't get to it before I take it to the shop on Monday.

I tried to find the thread I was referring to but no luck. I should have mentioned a few things. The jerk happens when I'm applying the brakes and can also be felt when simply coasting to a stop and not applying the brakes. I updated my post because last night I coasted to a stop without any brakes applied and I felt the jerk. It almost feels like a downshift but the car sort of lunges forward. Not a violent lunge but it's not something I've felt in other cars.

Anyway, thanks for the info and I'll keep everyone updated on the outcome next week when it goes to the shop.

Do our cars have engine and transmission mounts that need to be replaced over time?

I personally have not heard of this being an issue in the GS but I could be mistaken.

Hey, did you ever find what was causing the downshift jerk?

I would do an induction cleaning and replace the plugs, and clean the throttle body. Could be carbon build up on the plugs, giving you a slight miss fire or hesitation

Are you sure it might just not be a suspension component? If a suspension linkage is broken like rusted through, you could hear similar things.

same issue....
 

So I get a jerk when coming to a stop. Took it to lexus and the did the recall and got pistons etc but problem still there. Then they tell me its the transmission (code shift solenoid B performace). I then take it else where to do a transmission swap but still have the same problem! Do I need to get the new transmission coded? What am I missing here?

Please help! any info will do. Thanks 2006 is250 rwd

Does it happen only when cold? I notice that when the car is cold I get some ruff downshifts, but after normal operating temperature everything is fine ( until i do some hard braking and I am in the power mode) Power mode does some hard downshifts, might want to keep it in normal. Also for sake of just trying, put it in snow mode see if you still notice same symptoms.

I'm on Sport shift most of the time in LA traffic and I get what you mean when the jerking happens from downshift from 2nd to 1st. As I get to learn the sweet spots on downshifting... I shift from 2nd to 1st around 2000rpm-1500rpm for that engine braking feel. I get that unexpected jerk if i downshift from 1000rpm and under. Hope that puts info on unexpected jerking cause it feels like i shat in my pants when that happens.

I have literally the EXACT same issue as the original poster. Right at 8 mph during deceleration, whether braking or even an idle roll, I get what feels llike a rough stall/jerk. I know it's not suspension or brake related and it only happens when stopping, never in acceleration.

Thanks in advance for any help you guys may provide

Same problem here!!!
 

Just a voilent jerk when coming to a stop ...any ideas of what it could be?

Sounds like the engine mounts, my old acura legend had the same problem till I changed out the mounts....it could be something else.