For some reason I think this might affect a lot more vehicles than just the 2008 Sonata 4 Cyl.

DESCRIPTION:

Some Sonata 2.4L vehicles with automatic transaxles may experience a vibration,
shudder or booming noise at 38-42 mph in 4th gear. If so, follow the procedure to
update the ECM and TCM.

APPLICABLE VEHICLES:

Model: 2008 Sonata 2.4L (NFA) vehicles with automatic transaxles

Yes for sure, I just had this happen to me today in my v6. A shudder is that best way to discribe it.

This post has been edited by PaulW: May 26 2008, 07:14 PM

Exactly, shudder is a great word.

...But then they claim it to be limited to the I-4 and only 2008.... Weird... Why only 2008 cars?

As posted before, I was trying to listen/feel it when coasting at around 40-42mph and all I could hear is a VERY faint, umm... yes, shudder.... But this was so subtle and faint I would've never noticed it if I didn't really try to.

I dunno, maybe some one high enough up the totem pole bought one and they had enough clout to get a TSB made for it. When Gracie does it I can feel it more through the pedals than anything else. If it's the same thing, and it sounds like it could be.

TSB = ?

Ha, I'm watching TBS right now. All TSBs are pinned at the top.

Technical Service Bulletin. You can find them all here if you'd like to have a look. Whenever I post up a new one, or someone sends me a new one, I put them there. :57:

Hey do any of you guys ever get a shudder when going from reverse to drive when the car is cold? I get it about 1 in 15 to 1 in 30.

Paul

Is it a shudder or a jolt?

I'm not sure what would cause a shudder.

A jolt could happen if you didn't come to a complete stop or if the engine idle is above 1,000 RPM (you mentioned that the car was cold). The higher RPM would "jerk" the transmission into the forward moving gear in a similar way as when you are still rolling in reverse and shift to drive. The latter (IMO) would be considered normal behavior.

That seems the most likely culprit and I doubt there's much you could do about it. How many miles do you have on your car? It may disappear with a transmission flush.

I have had this since day one. at almost exactly 40MPH with the throttle position slightly accelerating - the car shutters like its in too high of a gear (its at the point where is just shifts to OD). I was thinking it was something that I had to live with, but now I see perhaps not. Anybody have the car flashed yet?

it has happened in almost every car I have owned.. at 40 or 45, the car wants to shift into the higher gear, but its just a TAD too slow to really stay there... if you are still accelerating past that speed, it goes right by it with hardly a notice...

i personally think this is just a problem with cars in general... thankfully, i dont have the issue much since i am either going 35 en route to the highway (a mile from my house) or going 65-70 on the highway, so I dont feel it too much...

Yea, and even other makes. I'm hearing lots of complaints on the Toyota forum too. When the torque converter locks up at ~ 45mph, it's like the engine is suddenly in too high of a gear for the engine RPM. Thus you get the shudder/lugging/booming sound.

I notice it in my 06 too, but since the V6 has plenty of torque, it's very slight.

And thanks again MH for keeping the TSB site. Much appreciated!

It's a shudder for sure, not a jerk. I pull out of the drive way in reverse, but it into drive nice and slow while I'm at a full stop and sometimes I feel a "shudder shudder shudder". Sometimes only once and it's over quick, sometimes multiple times. I have also experienced it coming from a just park to drive as well. It seems like it's almost having trouble getting into gear. I had my transmission serviced at 24k when I bought the car used and I've also had the adaptive values reset by the dealership. It didn't help at all.

Paul

What is the fix? Remapping the shift points??

when you had the trans serviced what fluid was used?

Our 08 I4 is in the TSB...but we dont have any "shutter". I do notice a "dead spot" though right around 40 where the car should not be in 4th...it sort of just hangs out there until you get the toque at around 45+ mph or you mash it hard enough to drop to 3rd.

We are taking the car in to have them make the door locks lock automatically...so I will bring this up since they will be flashing anyway.

I took the car in, it was flashed as the TSB states and it completely cured the issue. Talking to the mechanic after he test drove the car post flash, he stated that he doesnt think it changed the shift points - however he noticed that the torque converter that used to lock in at 39 MPH now locks in at 46 MPH. in switching to the shiftamatic thing, I see it is in 4th gear at 35-37 MPH when gently accelerating so it had to be a harmonic that the TC was transfering - now that it still floats to 46 MPH, no vibration. I havent notices any significant MPG loss and Im a bit anal about that stuff to.

Excellent news.

My wife wants me to take the car in to have the locks changed to auto lock...so we will knock this out too.

When you take it in ask them if it's the same thing that the other years are doing, including the V6 models, if you would. Not that they'd know but it might be worth a shot.