A6 odd shift issue
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From: Out Where the Buses Don't Run, Eglin AFB/ Niceville FL
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A6 odd shift issue
I have a 2006 with the A6 trans that I bought new. In 2009 I added a Vortech supercharger kit. I had the car professionally tuned right after and had them tune it on the conservative side as it is strictly a street driven car. I have had no issues until recently.
Here is the oddity. In "D" mode the car shifts through all 6 gears normally even under heavy throttle. In "S" mode when it goes from 4th to 5th it jumps back into 4th hard under throttle. If I let off it will shift back into 5th. At normal throttle it will also jump through 4th into 5th and then slam back into 4th momentarily and then shift into 5th. In paddle mode, it shifts normal.
There are no codes and looking at it through HP Tuners, everything appears normal as far as shift point settings are concerned. There is a weird squeal noise for lack of a better description when it does the 4-5-4 dance. The car has 31K miles on it with all but 13K supercharged. The trans fluid is original but the diff fluid has been changed twice.
Any ideas? Thanks.
Here is the oddity. In "D" mode the car shifts through all 6 gears normally even under heavy throttle. In "S" mode when it goes from 4th to 5th it jumps back into 4th hard under throttle. If I let off it will shift back into 5th. At normal throttle it will also jump through 4th into 5th and then slam back into 4th momentarily and then shift into 5th. In paddle mode, it shifts normal.
There are no codes and looking at it through HP Tuners, everything appears normal as far as shift point settings are concerned. There is a weird squeal noise for lack of a better description when it does the 4-5-4 dance. The car has 31K miles on it with all but 13K supercharged. The trans fluid is original but the diff fluid has been changed twice.
Any ideas? Thanks.
Le Mans Master
Joined: Apr 2011
Posts: 7,820
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From: Montreal
St. Jude Donor '13
I would think the 4-5-6 clutch pack is giving up as that is usually what goes first on these transmissions. Shift points don't change by themselves unless something changed on the car, so its probably not in the tune. When those clutches go you wont get any codes. You might check the oil for level and a burnt smell for clues, but probably time for a rebuild or replacement.
Let us know the outcome. Good luck.
Let us know the outcome. Good luck.
Thread Starter
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From: Out Where the Buses Don't Run, Eglin AFB/ Niceville FL
2025 C8 Z06/7/E-Ray of the Year Finalist - Unmodified
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I would think the 4-5-6 clutch pack is giving up as that is usually what goes first on these transmissions. Shift points don't change by themselves unless something changed on the car, so its probably not in the tune. When those clutches go you wont get any codes. You might check the oil for level and a burnt smell for clues, but probably time for a rebuild or replacement.
Let us know the outcome. Good luck.
Let us know the outcome. Good luck.
Thread Starter
Race Director
Joined: Jul 2000
Posts: 16,499
Likes: 2,384
From: Out Where the Buses Don't Run, Eglin AFB/ Niceville FL
2025 C8 Z06/7/E-Ray of the Year Finalist - Unmodified
2022 Corvette of the Year Finalist -- Modified
2021 C6 of the Year Winner - Modified
2020 C7 of the Year Finalist -- Modified
2020 C6 of the Year Finalist - Modified
I got the car back last night and completed the "learning" procedure today. The car now shifts like a new car. I'm happy to have S mode back again.
Melting Slicks
Joined: Nov 2013
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From: Memphis Tn
Thread Starter
Race Director
Joined: Jul 2000
Posts: 16,499
Likes: 2,384
From: Out Where the Buses Don't Run, Eglin AFB/ Niceville FL
2025 C8 Z06/7/E-Ray of the Year Finalist - Unmodified
2022 Corvette of the Year Finalist -- Modified
2021 C6 of the Year Winner - Modified
2020 C7 of the Year Finalist -- Modified
2020 C6 of the Year Finalist - Modified
Drifting
Joined: Sep 2009
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From: cinnaminson n.j.
St. Jude Donor '14
I suggest you double check on the new trans warranty. Gm wants dealers to deny power train warranty coverage if the car does not have the factory engine and trans programming. I don't see them warrantying a trans that's behind a non factory supercharged engine.
