A8 - the dreaded shudder
#1
Pro
Thread Starter
A8 - the dreaded shudder
I have a 2016 C7 Z51 A8 Vert with a little over 30K miles. I really like the A8 transmission but on a recent trip from Houston to Dallas I first noticed the "shudder" from the A8 which felt like a wheel going in and out of balance. I also noticed the A8 started grabbing second gear rather harshly at part throttle acceleration.
I took the Vette to my local dealer, Lone Star Chevrolet, with a copy of the TSB# 16-NA-175 bulletin which outlines the A8 shudder issue and remedy.
The first step is to do the triple-flush of the transmission. If that doesn't solve the issue, it is my understanding that TQ converter replacement is next followed by A8 replacement if the converter replacement is not successful.
The question I have is " How many folks with A8 shudder issues had the problem solved with just the triple-flush?"
I'm wondering if I should expect to at least see a TQ converter replacement before the issue is resolved.
The dealer has been a good service provider over the past 15 years so I don't expect any problems from them, I just am wondering what I should realistically expect before my A8 shudder is resolved.
Any feedback on your particular A8 shudder experience is greatly appreciated.
I took the Vette to my local dealer, Lone Star Chevrolet, with a copy of the TSB# 16-NA-175 bulletin which outlines the A8 shudder issue and remedy.
The first step is to do the triple-flush of the transmission. If that doesn't solve the issue, it is my understanding that TQ converter replacement is next followed by A8 replacement if the converter replacement is not successful.
The question I have is " How many folks with A8 shudder issues had the problem solved with just the triple-flush?"
I'm wondering if I should expect to at least see a TQ converter replacement before the issue is resolved.
The dealer has been a good service provider over the past 15 years so I don't expect any problems from them, I just am wondering what I should realistically expect before my A8 shudder is resolved.
Any feedback on your particular A8 shudder experience is greatly appreciated.
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Felon123 (11-02-2018)
#2
Race Director
I have a 2016 Z06 that had the shudder. It has been pretty much resolved with the triple flush that was performed last year.
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tomlink (07-09-2018)
#3
Racer
My 2017 GS has the shudder resolved with the flush procedure but the rpm fluctuations persisted.
I got rid of the car last month and the whole experience really took the excitement out of owning the car. It really was a beautiful car, but I felt like this was just a bandaid fix and eventually would give me problems in the future.
best of luck
I got rid of the car last month and the whole experience really took the excitement out of owning the car. It really was a beautiful car, but I felt like this was just a bandaid fix and eventually would give me problems in the future.
best of luck
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#4
My daughter owns a 2016 C7 with the 8-speed auto. It has 13,800 miles and now has the shuddering problem. The 8-speed auto in the C7 is a HORRIBLE transmission even without the shuddering. The paddle response sucks and feels like a slush-box accept at full throttle. My son owns a 2015 Scatpack Challenger with a ZF 8-speed auto and the V8-V4 feature, and that transmission is light years ahead of the 8-speed in the Vette. I have a 2014 F-type Jaguar with the ZF-8speed auto and it performs very similar to the one in my son's Challenger. I also own an Audi S4 with the 7speed dual clutch transmission. The ZF 8-speed transmissions in my son's Challenger and my Jag up shift and down shift almost as quickly with the paddles as the dual clutch in the S4 and do not feel like slush-boxes, unlike the 8-speed in my daugher's C7.
I still own an 02 Z06 Vette and a 95 LT1 Vette. I like the quick shifting ZF transmissions in my Jag and my son's Challenger and have no desire to own anymore stick-shift cars. I doubt I'll consider another Vette unless they source their auto (or dual-clutch in the C8??) from ZF or somebody that has a reputation for building quality automatic or dual clutch transmissions. GM designed automatic transmissions historically suck (I owned a 79 Trans Am with a Turbo 350 and a 1980 Pontiac Phoenix with some **** auto tranny - turbo 200?? - except for the turbo 400 which was good in its day) and the 8-speed auto in the C7 continues that sorry legacy.
I still own an 02 Z06 Vette and a 95 LT1 Vette. I like the quick shifting ZF transmissions in my Jag and my son's Challenger and have no desire to own anymore stick-shift cars. I doubt I'll consider another Vette unless they source their auto (or dual-clutch in the C8??) from ZF or somebody that has a reputation for building quality automatic or dual clutch transmissions. GM designed automatic transmissions historically suck (I owned a 79 Trans Am with a Turbo 350 and a 1980 Pontiac Phoenix with some **** auto tranny - turbo 200?? - except for the turbo 400 which was good in its day) and the 8-speed auto in the C7 continues that sorry legacy.
Last edited by resipsa; 10-05-2018 at 11:33 PM.
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tomlink (10-06-2018)
#5
Pro
Thread Starter
Lone Star Chevy did the triple flush which seemed to eliminate the shudder. The A8 still seems to select shift firmness at random and is slow to respond to throttle-induced downshifts. Seems to have a mind of its own sometimes. I’ve been advised that I still probably need to get the torque converter replaced to eliminate the problems.
I still like the A8, it is not that different from my Jeep ZF 8-speed (I don’t paddle shift). I’m hoping a converter replace will fix the gremblins.
I still like the A8, it is not that different from my Jeep ZF 8-speed (I don’t paddle shift). I’m hoping a converter replace will fix the gremblins.
Last edited by tomlink; 10-06-2018 at 09:17 AM.
#6
Burning Brakes
Member Since: Jun 2018
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I don't mind the A8 in my '17 GS so far, but I definitely do prefer our '18 Charger Scat's A8. We love that car period.
As long as I don't end up with any TC problems, I'm perfectly happy with the Vette But I agree, the paddles are S. L. O. W.
As long as I don't end up with any TC problems, I'm perfectly happy with the Vette But I agree, the paddles are S. L. O. W.
#7
Racer
i have 2017 z06 only 800 miles thus far. have not noticed this issue. hope i never do. but anyway not knowing of this issue as of yet. i do love this car
#8
Drifting
I had the triple flush on my C7, 2016 Z51. The shudder is gone but I doubt this is a long term fix.
So I installed a RANGE device to stop the v4 and torque converter from locking and unlocking so much.
The second advantage is when applying throttle at cruise you don't have to wait for the v4 to switch to v8 and then a
downshift.
Sucks to have to delete a function you payed for but-so be it.
I am much happier with the shifts and drivability now.
If you need to go to the dealer for any other work the RANGE devise unplugs-no detectable change to the car.
So I installed a RANGE device to stop the v4 and torque converter from locking and unlocking so much.
The second advantage is when applying throttle at cruise you don't have to wait for the v4 to switch to v8 and then a
downshift.
Sucks to have to delete a function you payed for but-so be it.
I am much happier with the shifts and drivability now.
If you need to go to the dealer for any other work the RANGE devise unplugs-no detectable change to the car.
#9
Racer
My 2016 Z51 with just under 30k miles is at the dealer now for this.
The first time I took it there, the tech just did some updates to the software and said it was fixed.
He was obviously not a very good mechanic, because I noticed it after about 5 miles on my way back home.
I don't have word yet and what they plan to do.
Hopefully they will just go ahead and replace the torque converter.
I'm more worried about what kind of accelerated wear all that caused in my transmission.
The first time I took it there, the tech just did some updates to the software and said it was fixed.
He was obviously not a very good mechanic, because I noticed it after about 5 miles on my way back home.
I don't have word yet and what they plan to do.
Hopefully they will just go ahead and replace the torque converter.
I'm more worried about what kind of accelerated wear all that caused in my transmission.
#10
Instructor
Even if you have never had the shutter, you will unless you:
1. Have the original fluid flushed out and replaced with Mobil 1 LV which the current GM recommendation.
2. Run a Range AFM disabler or use HP Tuners to shut it off.
Bonus: use HP Tuners to zero the slip tables in the TCM in addition to the above
Once you get the shudder, you’ve already started damaging the torque converter... a triple flush is just prolonging the issue until you are outside of warranty...
1. Have the original fluid flushed out and replaced with Mobil 1 LV which the current GM recommendation.
2. Run a Range AFM disabler or use HP Tuners to shut it off.
Bonus: use HP Tuners to zero the slip tables in the TCM in addition to the above
Once you get the shudder, you’ve already started damaging the torque converter... a triple flush is just prolonging the issue until you are outside of warranty...
Last edited by Joshinator99; 10-16-2018 at 12:47 PM.
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astaggs (02-13-2019)
#11
Thanks to all of you who outlined the issue with the shudder, which I originally spelled wrong. My C7 is in the shop now for that and I have made him aware of the bulletine and the remedies.
Thanks to all
Thanks to all
#13
Instructor
Just bought a 2015 Z51 with 27K miles on it...what should I be looking for? What does the shudder feel like and when does it happen? I have about 2 months left on Warranty is there anything I should be doing?
#15
Shudder feels like you are running over speed bumps, like the ones as you enter EZ pass. Shudder occurred when I would be traveling at a steady speed, like 50, go down to 48, then return to 50, during the return I would feel the shudder. Like running over several speed strips. My Z51 is being fixed as we speak and I only have 9,000 miles on it. Hope this helps.
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2Intense (11-03-2018)
#16
Race Director
That video posted above has nothing to do with the A8 shudder, it's the warbling sound with the base differential, and can happen on M7 cars too (but people notice it more on the automatics because it occurs at around 1500rpm and manual drivers tend to keep the revs higher than this.
A8 cars that have the electronic differential do not suffer from the warble, only the base model Stingray.
A8 cars that have the electronic differential do not suffer from the warble, only the base model Stingray.
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2Intense (11-03-2018)
#17
I was just at the dealer for this issue with studder. They didn't even teat drive the car. They are going to order the new ATF oil and will change it three times this Friday. I was also told that GM will not be replacing the TC's any more since this is not the issue. This includes replacing the tranny filters as well. It is a fluid issue and they will replace the fluid as many times as need until the spring of 2019. Then there should be a ECM update to fix the studded permanently.
I don't know if the issues is causing any damage to the tranny itself which is why GM is not replacing or inspecting the tranny oil filters for metal. I'm going to ask the master mechanic who will be doing the work about inspecting the filter for metal shavings.
I will keep you posted on what I find out.
I don't know if the issues is causing any damage to the tranny itself which is why GM is not replacing or inspecting the tranny oil filters for metal. I'm going to ask the master mechanic who will be doing the work about inspecting the filter for metal shavings.
I will keep you posted on what I find out.
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2Intense (11-06-2018)
#19
Pro
Thread Starter
A8 shudder issues should be covered under power train warranty. Make sure you google and download a copy of GM TSB #16-NA-175 bulletin which specifically addresses the A8 shudder issue - bring it with you to the dealer service dept.
#20
Burning Brakes
I just had a 2017 Grand Sport at the dealer for the shudder. They did the trans fluid flush and it did not help. A technician monitored the torque converter while driving and showed that the converter was still shuddering. He said they are not allowed to replace any more converters until a new one is released in a few months. Then it can be replaced with the new converter.