C7 General Discussion General C7 Corvette Discussion not covered in Tech
Sponsored by:
Sponsored by:

Question

Thread Tools
 
Search this Thread
 
Old Jun 15, 2023 | 11:52 AM
  #21  
Dcasole's Avatar
Dcasole
Le Mans Master
10 Year Member
Community Builder
Liked
Loved
 
Joined: Oct 2014
Posts: 8,680
Likes: 2,729
From: Atlanta GA
Default

Originally Posted by TxLefty
I hope that is the case. Since the problem apparently appeared after the flush, a low fluid level could be a possible cause. If it is due to the issue in the Service Bulletin it would be an interesting coincidence.
Harsh shift engagement is not caused by fluid and there is a TSB out for converter leakdown which requires the removal and replacement of the valvebody but that only affected a small portion of transmissions

The relearn process should be done FIRST , this process runs the clutches thru a series of tests to determine how much presure to apply to engage and also measure the time on how long it takes to disengage each clutch . After procedure is performed the tech should do a drive cycle varying speeds etc as the TCM is now in a learning phase measuring the RPM , Preasure ETC that it takes to make a perfect engagement each and every shift and also when placed into gear .

Your trans might shift funky for 50 miles or so while it's in this learning stage , I recommend that you drive it like you stole it

Then I can assure your trans will engage smoothly and shift perfect

Dave
Reply
Old Jun 15, 2023 | 12:46 PM
  #22  
Squeaky Wheel's Avatar
Squeaky Wheel
Drifting
Veteran: Air Force
Liked
Loved
Community Favorite
 
Joined: Jun 2015
Posts: 1,871
Likes: 695
From: Lagrange KY
Default

Originally Posted by Dcasole
Harsh shift engagement is not caused by fluid and there is a TSB out for converter leakdown which requires the removal and replacement of the valvebody but that only affected a small portion of transmissions
Dave
AH, That’s it! That’s what I was thinking of in my post #2. Was thinking it had something to do with a part (valve body) needing to refill after a leak down overnight. So it’s a torque converter problem, not exactly a transmission one. My understanding is that can be a pretty costly fix.

Curious why starting out using the paddles seemed to alleviate the problem? Maybe because it was being held in 1st gear a bit longer before I shifted to 2nd? It appears that the 3x flush, had I had it performed, wouldn’t have helped any.
Reply
Old Jun 15, 2023 | 01:07 PM
  #23  
Dcasole's Avatar
Dcasole
Le Mans Master
10 Year Member
Community Builder
Liked
Loved
 
Joined: Oct 2014
Posts: 8,680
Likes: 2,729
From: Atlanta GA
Default

Originally Posted by Squeaky Wheel
AH, That’s it! That’s what I was thinking of in my post #2. Was thinking it had something to do with a part (valve body) needing to refill after a leak down overnight. So it’s a torque converter problem, not exactly a transmission one. My understanding is that can be a pretty costly fix.
No not converter problem its a valve body problem that allows the converter to leak down

Before you condemn anything , do the garage relearn that i mentioned above becaue there is a 95 % probability that this will solve your issue

Curious why starting out using the paddles seemed to alleviate the problem? Maybe because it was being held in 1st gear a bit longer before I shifted to 2nd? It appears that the 3x flush, had I had it performed, wouldn’t have helped any.
This is the tip off that i dont think you have any issues with converter leakdown and you need a garage relearn , yes it's because you are holding the gears and not allowing the TCM to shift it

Dave
Reply
Old Jun 15, 2023 | 02:27 PM
  #24  
Squeaky Wheel's Avatar
Squeaky Wheel
Drifting
Veteran: Air Force
Liked
Loved
Community Favorite
 
Joined: Jun 2015
Posts: 1,871
Likes: 695
From: Lagrange KY
Default

Originally Posted by Dcasole
No not converter problem its a valve body problem that allows the converter to leak down

Before you condemn anything , do the garage relearn that i mentioned above becaue there is a 95 % probability that this will solve your issue


This is the tip off that i dont think you have any issues with converter leakdown and you need a garage relearn , yes it's because you are holding the gears and not allowing the TCM to shift it

Dave
Thanks Dave. Good information that I wish I had known. I’m sure it’ll help others who may be encountering the issue. It’s a moot point for me now, as I got rid of the car 5 years ago. Have recently acquired a 2014 C7 2LT Z51 coupe with the A6. Much happier with it, although the ride is a bit harsher than the base 2016 was.
Reply
Old Jun 15, 2023 | 05:59 PM
  #25  
Gearhead Jim's Avatar
Gearhead Jim
Team Owner
Supporting Member
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Sep 2000
Posts: 25,029
Likes: 2,719
From: Far NW 'burbs of Chicago
St. Jude Donor '13
Default

I think there are several different issues with the A8:
Stutter/shudder under light throttle. The "redesigned" fluid is supposed to fix that, and it usually does.
Delayed/harsh engagement into D, usually on first drive of the day. Requires new part and expensive labor to fix.
Lurch on first 1-2 shift each day. That's the only problem we have, and the manual 1-2-1 shift mentioned in post #7 solves that for us. Any actual fix would have to be quick/easy/cheap, for me to bother.
Reply
Old Jun 15, 2023 | 08:09 PM
  #26  
Dcasole's Avatar
Dcasole
Le Mans Master
10 Year Member
Community Builder
Liked
Loved
 
Joined: Oct 2014
Posts: 8,680
Likes: 2,729
From: Atlanta GA
Default

Originally Posted by Gearhead Jim
Lurch on first 1-2 shift each day. That's the only problem we have, and the manual 1-2-1 shift mentioned in post #7 solves that for us. Any actual fix would have to be quick/easy/cheap, for me to bother.
Jim as I mentioned hard or sloopy shifts are 99% of the time fixed with the relearn procedure. This goes of not only the A8 , it also applies to the A6 .

Anyone with HPtuners GDS2 or some other high end diagnostic tools can perform the procedure. I had 1st to 2nd shift flair... on both my C6 and my C7 . Ran the procedure and it cured the issue . I have done it for several of my friends that has hard downshift or upshift complaints and we were able to correct it for them .

Dave
Reply
Old Jun 15, 2023 | 08:19 PM
  #27  
Gearhead Jim's Avatar
Gearhead Jim
Team Owner
Supporting Member
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Sep 2000
Posts: 25,029
Likes: 2,719
From: Far NW 'burbs of Chicago
St. Jude Donor '13
Default

^^^^^
Not a big problem for me. but I'll look into the relearn. Thanks.
Reply




All times are GMT -4. The time now is 07:55 PM.

story-0
2027 Chevrolet Silverado 1500 First Look: Everything You NEED to Know!

Slideshow: Is the 2027 Chevrolet Silverado 1500 the best Silverado yet?

By Michael S. Palmer | 2026-06-16 08:01:12


VIEW MORE
story-1
5 Best & 5 Worst Corvette Daily Drivers

Slideshow: 5 best and 5 worst Corvette daily drivers

By Joe Kucinski | 2026-06-15 10:32:13


VIEW MORE
story-2
The Headlights of Every Corvette Generation Explained

Slideshow: The headlights of every Corvette generation explained

By Joe Kucinski | 2026-06-15 10:17:14


VIEW MORE
story-3
5 Best & 5 Most Overrated Corvette Track Packages of All Time!

Slideshow: The 5 best and 5 most overrated Corvette track packages ever.

By Joe Kucinski | 2026-06-09 12:46:45


VIEW MORE
story-4
Every 2027 Corvette Engine Explained

Slideshow: Every 2027 Corvette engine explained

By Joe Kucinski | 2026-06-09 12:16:31


VIEW MORE
story-5
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette

Slideshow: A Jaguar designer's personal project imagines what a modern front-engined Corvette might look like if Chevrolet revisited the golden age of the Stingray.

By Verdad Gallardo | 2026-06-08 19:53:43


VIEW MORE
story-6
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-7
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-8
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-9
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE