TOY 15

Have a 2017 Z06 convertible 2700 miles WITH dealer installed MRC upgrade, (200 miles ago all city driving) first time on highway and car acts if it is on a continuous railroad track Really noticeable rough ride even in TOUR mode
Don't believe it is a torque converter issue since there is no noticeable "clunking" when it shifts gears in full automatic mode
idle is constant with no wide fluctuations
Dealer is at a loss, hesitant to provide 3 fluid changes

Anyone else have this problem? Solution?

Warp Factor

Your post is very confusing!
What is it that you want to know about? Magnetic Ride Control, automatic transmission issues, variations in idle speed, or wheel alignment issues?

RegnaR

Is it speed dependant? Sounds like you might have some bent / cracked wheels

tertiumquid

The MRC needs some driving time to readjust itself so that may be your problem. If you had the rough ride before you did the MRC and did the MRC to get rid of the rough ride and still have it, then you're probably into the TC caused scenario.The clunking is not usually present as part of the torque converter problem. The triple flush and a re-flash of the A8 will likely fix the clunk and possibly the shudder (that's probably what you're feeling) if you catch it early enough. The TC rumble feeling will start around 25-30 mph and continue up to 80 mph. It's like driving on a rumble strip but not quite as bad...just annoying as hell. It seems worst between 40-50 mph. If your car has been doing this for a while, it's likely damaged the TC. If it just started, get it triple flushed now. If the dealer is hesitant, tell him to look it up; there is a service bulletin on this very problem. .The cause on the 15-17 cars was the original viscosity of the transmission/TC fluid. If the dealer won't do it, find another dealer; this is a known and widespread problem with the A8 in those years. One other possibility is what another poster mentioned and that is one or more bent wheels. If you recently hit a pothole or even a small pavement ridge, it's likely you bent a rim. Many of us have found our wheels to be bent and cracked and didn't even know it until they were put on a force balancer. One of mine was actually egg-shaped enough to where it was wearing the high spot on the tire more than the rest of the tread. Three were cracked and bent....in 6K miles, no tracking and no known hits on anything.

tertiumquid

PM'd you with a TSB link