I feel like my shift times are taking forever, especially under heavy throttle. Its almost like the gearbox just hangs and takes 2-4 seconds to shift.

I've been researching the forums, and thought the clutch re-learn would help - that didn't. Also been reading threads to see if its just a worn clutch, and doesn't sound like that either. Car is April 2010 with 14k miles.

At this point, I'm wondering if it could be software or something else mechanical. Any ideas?

I can take to the dealer under warranty, just trying to avoid wiping my aftermarket ECU tune (which could be the ultimate issue, but the issue came about 2 months after the tune).

Sorry to say this but 14k is about when I have seen clutches go. Not saying that is whats wrong. But it might be slipping.
Notice any drips? Have seens a few shifter units leak.
Is the ECM tuned or the TCM? If the ECM then you dont need to worry about any reflashes. There are some updates for the TCM that might help.

Thanks for the quick response. I believe the ECM is tuned, not the TCM but am checking. I will likely end up taking it to the dealer. Keep you posted if they find a solution.

I had no issues with my last vantage in 23k miles
I did find the shift was a lot better if you lift slightly just before it changes

Hey, met ya at the C&C - I have the silver vert, same year. Anyway I've always felt as if the shifts have been slow on the car. So I got the SS remap and shortly after I had similar issues and thought it was from the remap, however it was a clutch failure - just bad timing. I say this because my clutch went out at around 16/17K, so that's a strong possibility even at 14K...which even at 16/17K I was upset after what I had researched on the forums also.

Thanks for letting me know. I just spoke to the tuner, and he said to try disconnecting the battery overnight to reset the computer. Said he sees this a lot on MB AMGs - after several weeks of daily driving, the computer adapts and the shifts slow down. So he said the battery reset works every time.

That being said - does anyone know if the battery disconnect switch will work?

BTW if it is bad often doing 3 or 4 clutch learns together improves it.
Makes sure aircon is off when you do it!

Quick update - the dealer flashed the TCM (transmission control module), and noticed that the clutch re-learn procedure was not working. They resolved that and ran the re-learn several times. Shifting seems to be better, though weather is really nasty today so couldn't push throttle to test it out during rush hour.

Thanks for all the input here.

How much does a clutch replacement cost..I have a 2009 AM V8 with same problem.. I purchased the car with 10000 miles, and have the same problem.

Unfortunately clutch replacement ends up being $5500 to $6000.

They tend to wear fast, especially with the Sports Shift, but they've also been known to fail. My 09 broke a clutch spring, but since it was still under warranty it was covered.

I'd really like to know how the "clutch re-learn procedure was not working". That sounds like a great way to have the clutch wear faster without ever knowing about it.

Do you guys have any info or experience with the transmission remap that is offered by RSC?

I have it and its very good. Shifts become significantly faster and smoother. Driving in D is also better because it holds shifts longer.

What year is your vantage? My understanding is that the sportsift was upgraded in 2009.

ASM1 had a software update on the MY09 cars
It was replaced by ASM2 in the S and MY13 cars

The TCU wasn't taking the relearn because it was the old software, dealer updated the software so they can reset all specs with there AMDS(haven't talked with them, but this sounds about right)...then they got stuck most prob because of the reset it resulted in no drive because the clutch spec was reset to new spec which is 1300bits..if your above 1600bits but less than 1700bits a couple clutch relearns will get the car functioning again...in all honesty, if all this is right on the money.. and I was in ur shoes, I'd be putting that clutch cash aside with that mileage...average mileage I replace the original ASM1 clutch is 10,000km-20,000km's, new units have been revised to solve issues..I don't see any V8V's here over 40,000km so I couldn't tell you when the new revised unit would wear out on ASM1..