Pre purchase inspection by an independent source, or walk. Too many other Vettes out there.

 

When driving the car, take it on a level highway where you can set the cruise control to 60 mph, 70 if possible. Run it for about 10 miles in automatic mode and see if you feel any shudder (some people say it is similar to running across rumble strips). GM disengages the Torque Converter Clutch (TCC) whenever AFM switches between 8 and 4 or 4 and 8 cylinder operation. AFM tends to activate whenever a car traveling at a constant speed encounters a slight rise or dip in the road. On a rise, the TCC will more than likely disengage while the engine switches from 4 to 8 operation and disengage again on a subsequent dip and the engine switches from 8 to 4. You may not notice the slight rises or dips but the car will. Whenever the TCC disengages and reengages, you might notice the shudder.

You may also notice the shudder when the transmission downshifts as the TCC may disengage when dropping from one gear to another, such as when slowing for a turn, stop, etc.

To prevent AFM from activating, place the A8 in Manual Mode, then use the paddles to shift the transmission gears up and down.

I don't have an A8 but have been hearing about the shudder problem since 2015. My car is an M7, and I have placed it in Eco Mode and used cruise control to hold the speed at 70 mph on a level highway. AFM would activate on rises and dips and I could see the tachometer moving up and down several hundred rpm whenever it happened (drops during 4 cylinder operation/rises with 8 cylinder operation. On the M7, the change is almost imperceptible since the clutch is always engaged.

The Range Device prevents AFM from activating, so the TCC doesn't disengage/reengage as often. 40+ years ago, when the TCC was first introduced, they weren't locked so would disengage/reengage all the time, causing some shudder. That is why the automakers started using locked TCCs.

Bill

 

Just wanted to update. I wasn't able to strike a deal with the cars i was looking at when I created the post. The first car sold 30 minutes before I arrived at the dealer, 2019 stingray 1LT, 17,000 miles. The second car sold the night before my appointment with the dealer, 2017 stingray, 1LT, 22,000 miles. The 3rd car was over 300 miles away, tried negotiating thru email but the dealer wouldn't budge on the price so I bowed out, 2017 stingray, 2LT, 17,000 miles. 4th time was a charm. I got what I believe was a great deal on a 2017, stingray, 2LT, 4,200 miles. We had to drive over 300 miles to get it but so far everything seems to be OK! We rented a car so we could ride back together and it was a blast!!

Thanks again for the great advise and help with this purchase.

 

Well, we are waiting for pictures.

 

[img alt="Only pic i have so far.
"]https://cimg4.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/960x1280/_1099912302614402093_a1b03b9028cc689abf7 5fdae33d6bbbc92afe199.jpg[/img]
Only pic i have so far.