[Strange Flavor]

Got my car back and it feels much smoother after the 3 flush. I haven't felt the rumble strip feeling again yet but there might still be a little shuddering still, can't tell if its a mind thing now. If it is there it is definitely not as bad as it was. The service guy said if I bring it back in a couple hundred miles he would just replace the torque converter if I wanted, he said he may still feel it a little too. Probably going to take him up on that offer.

[wrankin]

Originally Posted by grampa_ss

Question for you guys....

How bad is the shudder you guys are feeling? if I had it would I immediately know it? or is it something you have to try and feel?

Mine felt like you were driving a on a rumble strip

Bill

[Strange Flavor]

Originally Posted by wrankin

Mine felt like you were driving a on a rumble strip

Bill

+1

If not for this I would have overlooked whatever V4 shudder I was feeling. The Rumble Strip feeling every 10 to 15 seconds was VERY apparent and was driving me nuts. That being said, when it is in V4 now it does feel smoother. Random hard 1 to 2 shifts also haven't reoccurred, not that the hard shift bothered me. I guess the randomness of it was weird though.

[Speedy1975]

Update on mine

Second dealership did analysis with their scan tools detected more than acceptable torque converter slip and have ordered a replacement. Amazing these guys could diagnose the issue when first dealership claimed they couldn't even replicate the problem. If you're in the middle TN area, stay away from Murfreesboro Chevrolet. I'd not let them work on my lawnmower.

We'll see how long it takes to get it back, so far this is week three without the car.

[tcbracing]

Originally Posted by leadfoot93

I had my flush done yesterday, it was nice not having the shudder. But we'll see if it lasts or not.

Took mine in Friday and the dealer needed to order the Trans fluid, filter and pan gasket. Supposed to be in today so I should have mine done by mid week.

Had all of the same symptoms on this thread except for noise. Shudder was getting so bad that it would stay if I kept a light throttle on a slight incline in V4 mode. Little throttle tip in and back to V8 and it goes away, for the most part.

17,XXX miles. 50% easy/50% hard driving. Lot of paddle shifting.

[Wagnbat]

Mine started doing this just after 10k, just felt like a little bit of subtle warble/vibration... I'm at 12k now and it is clearly apparent that it is not normal and getting worse. Happens mostly in V4 when cruising at any highway/freeway speed in overdrive.

Just staying at one speed, over about 120 seconds will cause the vibration to start and then consistently grow until I change speed. Letting off the pedal or putting on the pedal ever so slightly is more than enough to get it to stop... For another minute or so, and then it's right back at it. Consistently changing gas-pedal depression on the highway prevents it from occurring.

I have an appointment for the middle of next week for Speedway Chevrolet to have at it.

[dray]

Found something that kinda helps. When the vibration occurs, if I hit the left paddle shifter, then it drops down a gear and goes to manual shift mode temporarily. Vibration goes away. It switches back to automatic mode on it own after a bit.

Wish I had got the manual, but my wife refuses to learn how to drive one.

[Klayman]

Originally Posted by dray

Found something that kinda helps. When the vibration occurs, if I hit the left paddle shifter, then it drops down a gear and goes to manual shift mode temporarily. Vibration goes away. It switches back to automatic mode on it own after a bit.

Wish I had got the manual, but my wife refuses to learn how to drive one.

If I am driving on the freeway, I place the shifter in manual, I down shift with the paddle to 7 then up shift to 8. then it will not go into AFM mode where the engine switches back and forth to 4 cylinders and 8 cylinders, It will stay in 8 cylinder manual mode all the time. 4 cylinder mode on a slight incline was the worst vibration I experienced. (May have to switch down to 7 and back to 8 twice.....I haven't done it since the flush...I'll try again today....but i was successful in keeping it on 8 cylinders for a 40 minute freeway cruise with CC on...and it will automatically downshift for you at a certain point while slowing down.)

I'm in the same boat....momma don't drive manuals....lol

[SuperSound]

Originally Posted by dray

Found something that kinda helps. When the vibration occurs, if I hit the left paddle shifter, then it drops down a gear and goes to manual shift mode temporarily. Vibration goes away. It switches back to automatic mode on it own after a bit.

Wish I had got the manual, but my wife refuses to learn how to drive one.

Originally Posted by Klayman

If I am driving on the freeway, I place the shifter in manual, I down shift with the paddle to 7 then up shift to 8. then it will not go into AFM mode where the engine switches back and forth to 4 cylinders and 8 cylinders, It will stay in 8 cylinder manual mode all the time. 4 cylinder mode on a slight incline was the worst vibration I experienced. (May have to switch down to 7 and back to 8 twice.....I haven't done it since the flush...I'll try again today....but i was successful in keeping it on 8 cylinders for a 40 minute freeway cruise with CC on...and it will automatically downshift for you at a certain point while slowing down.)

I'm in the same boat....momma don't drive manuals....lol

Klayman is right. The downshift then upshift is what keeps AFM from reengaging. But I can tell you both once the issue becomes bad enough, the shudder will appear in V4 and V8 modes, as well as shuddering while shifting on light accel. Then it started the shudder at interstate cruise speeds if there was any incline (V8 or V4). That's when it went in for service. My car went from occasionally shuddering to the above in about 2K miles.

[Speedy1975]

I'm curious why you guys are trying to find workarounds for an obvious TC defect LOL

Just get it fixed.

[Klayman]

Originally Posted by Speedy1975

I'm curious why you guys are trying to find workarounds for an obvious TC defect LOL

Just get it fixed.

Just something I did until I got the triple flush.....I had the rumble strips in V8 mode but it wasn't half as bad as the low rpm V4 shakes....

[Speedy1975]

Word. The dealer went straight to a torque converter replacement on mine. They tried some kind of software update first....never even mentioned a flush like I expected they would.

[Klayman]

Originally Posted by Speedy1975

Word. The dealer went straight to a torque converter replacement on mine. They tried some kind of software update first....never even mentioned a flush like I expected they would.

From what I have read, they have updated the TC and if you have an older model TC, they change it out.

[Klayman]

There is alot of discussion on the corvette forums about the A8 shudder and many believe that the Torque Converter (TC) is on the edge of design capacity and was built with inferior materials. So because of this, the active fuel management (AFM) causes undo stress on the transmission, TC and engine, by switching to and running in V4 mode, especially at low rpm's pulling a load on an incline. Many have installed AFM disablers that plug into the OBD port. This does not interfere with the programming, it just keeps the car in V8 all the time. I'm cautious to post links on the forum do to the moderators but if you google AFM disabler you can get them reasonably priced. I am waiting on how my flush works out hoping I can get a new TC first, but I will be getting one for my camaro for sure.

I don't think the fuel savings is substantial with AFM anyway. I would like to run in automatic V8 mode all the time. I will definitely compare MPG.

As far as I know, this does not leave any footprint on the ECM/TCM and can be unplugged when the car is not running.....hence, unknown should any warranty work be required.