Stingray Corvette Forum banner

41 - 60 of 125 Posts

·
Senior Member
Joined
·
18,667 Posts
UPDATE: Got my C7 back the other day with a new TC. The ride home was much smother with the new TC. Driving with my finger crossed hoping I never feel that shutter demons presence again.
Glad it is fixed, and we all hope you never experience it again!
 

·
Registered
Joined
·
7 Posts
Did you get a new TC or a whole new trannie? I just had mine in and they did the flush thing. A title better but not fixed. I am callin them tomorrow to let them know and push for anew TC or trannie. Do you know if these new parts are redesigned or just a different same type? Thanks

Greg

UPDATE. I got my car back a few days ago after having the TC replaced. I haven't driven it much but the shudder problem appears to be gone. I hit the sweet spot for the shudder (1300-1500 rpm) and it was as smooth as silk. The car seems to drive much smoother. No rattles or anything either after having the back end off to replace the TC. So far I am a very happy camper. I will get some more miles on it to be sure. BTW the dealer (Lindsay Chevrolet in Woodbridge Va) did an amazing job and keep me posted all along the way. When I picked mine up he told me there were 6 others in line to have the TC replaced. He also read somewhere that approx. 30% of the vets out there have this problem. Good luck to all going through this.

Greg
 

·
Registered
Joined
·
340 Posts
Did you get a new TC or a whole new trannie? I just had mine in and they did the flush thing. A title better but not fixed. I am callin them tomorrow to let them know and push for anew TC or trannie. Do you know if these new parts are redesigned or just a different same type? Thanks

Greg

You might not feel the full effects of the TSB flush for 300 miles or so, as it takes time for new fluid to do it's thing. As for a new TC or transmission, it is my understanding that the fluid flush is successful the vast majority of the time & very few TCs need replaced. I think it is more an issue of the original fluid not getting removed from the TC (easier said than done) & the new fluid not being able to replace it & that is why only some TC need replaced.
I read your other post about the shudder & not 100% sure you have the same issue, as you are not getting the shudder in V8 mode. The TSB states the shudder is apparent in V4 & V8 modes- this was definitely the case with our car.

We are still actually ongoing with this TSB. the initial flush seemed to solve the issue, but then the transmission pan gasket developed a slow leak (probably from being removed so many times during flush procedure). The gasket was replaced, but in an honest error, the old style fluid was added back into the transmission- I just happened to spot it on the work order. The car is going back in tomorrow, to have a second TSB flush procedure done as well as having a new transmission filter & pan gasket (GM really needs to add that info to the TSB IMO). Hopefully, that will be this issue finally solved for our car. HTH & best of luck getting your C7 sorted.
 

·
Registered
Joined
·
835 Posts
You might not feel the full effects of the TSB flush for 300 miles or so, as it takes time for new fluid to do it's thing. As for a new TC or transmission, it is my understanding that the fluid flush is successful the vast majority of the time & very few TCs need replaced. I think it is more an issue of the original fluid not getting removed from the TC (easier said than done) & the new fluid not being able to replace it & that is why only some TC need replaced.
I read your other post about the shudder & not 100% sure you have the same issue, as you are not getting the shudder in V8 mode. The TSB states the shudder is apparent in V4 & V8 modes- this was definitely the case with our car.

We are still actually ongoing with this TSB. the initial flush seemed to solve the issue, but then the transmission pan gasket developed a slow leak (probably from being removed so many times during flush procedure). The gasket was replaced, but in an honest error, the old style fluid was added back into the transmission- I just happened to spot it on the work order. The car is going back in tomorrow, to have a second TSB flush procedure done as well as having a new transmission filter & pan gasket (GM really needs to add that info to the TSB IMO). Hopefully, that will be this issue finally solved for our car. HTH & best of luck getting your C7 sorted.
That really must be frustrating! Hope they get it right this time. I would be beside myself.
 

·
Registered
Joined
·
340 Posts
Thanks, but things can & do go wrong, so I'm not too concerned. It was an honest mix up & the Dealership is being really good about it. Hopefully it all goes well tomorrow, but I'm going to meet with the Tech beforehand to make sure we are on the same page.
 

·
Registered
Joined
·
1,303 Posts
I just sent an email to my SA at Classic here in DFW. Lost a stinking key fob off my key chain (still have the key) and am taking it in to get the new one programmed to the car hopefully on Friday. Sent this procedure and asked how much it will cost to have performed on my car. Transmission on mine sees on occasion a lot of stress because of the modifications I have made to the engine so doing this will give me some peace of mind putting the Amsoil fluid in and flushing everything 100%!!!!! Mine being a 15 it is time to change it anyway, at least per the Busa Dave schedule. :)


Unfortunately I am guessing it will be $$$$$$ but you have to pay if you want to play.
 

·
Registered
Joined
·
99 Posts
Just started noticing it myself at 8,000 miles. I figured it might have to do with a software update that they performed after I got back from Bowling Green. I may need to drop it off at the dealership before I store it to get this checked out.
 

·
Registered
Joined
·
7 Posts
Update. I took mine in and the dealer did the flush routine. It made it better but didn't fix it completely. Back at he dealer today. GM has sent them a new TC. I hope they get this fixed. Will update more when I have info. BTW this started on my 2015 at around 8k. I have 11k miles on it now.
 

·
Registered
Joined
·
99 Posts
Just started noticing it myself at 8,000 miles. I figured it might have to do with a software update that they performed after I got back from Bowling Green. I may need to drop it off at the dealership before I store it to get this checked out.
Update: Car is at the dealer today. Of course I was told that they were not able to recreate the problem. Now I bear the burden of proving to them the issue I am talking about. It happens frequently enough that I assumed they would experience it too. Something I was wondering was if this is something that happens when the car is switching between V4 and V8 mode, but I did see it happen when the car was in V4 mode. Not exactly sure what to do from here besides taking the service manager for a drive so I can show them what I was talking about. I'm also not sure if the problem is exactly the same as what other people have reported in this thread. For me it is more of a nuisance than what I would call a serious issue, but if it is a problem that can be fixed, I would want them to fix it.

BTW: They suggested that the car would be acting differently after getting the software updated when I returned from Bowling Green last month. Almost sounds like a cop-out to me.
 

·
Registered
Joined
·
99 Posts
Update: Car is at the dealer today. Of course I was told that they were not able to recreate the problem. Now I bear the burden of proving to them the issue I am talking about. It happens frequently enough that I assumed they would experience it too. Something I was wondering was if this is something that happens when the car is switching between V4 and V8 mode, but I did see it happen when the car was in V4 mode. Not exactly sure what to do from here besides taking the service manager for a drive so I can show them what I was talking about. I'm also not sure if the problem is exactly the same as what other people have reported in this thread. For me it is more of a nuisance than what I would call a serious issue, but if it is a problem that can be fixed, I would want them to fix it.

BTW: They suggested that the car would be acting differently after getting the software updated when I returned from Bowling Green last month. Almost sounds like a cop-out to me.
Update #2: Stopped by the dealer yesterday and did a test drive with the Vette tech (34 years experience) there. Of course the shudder didn't happen in the short drive we took (I'm guessing because the car was not warmed up), but the guy understood what I was talking about. He said that he would do a "trans shift-sequence procedure" on the car and we could see if that addressed the problem. Anyone know what this is?? He said it was not a software update, but a procedure that allows the car to learn how and when to do shifts. Hopefully, I will get the car back today and get some drive time in before I have to store it for the winter. Stay tuned, sports fans...
 

·
Registered
Joined
·
10,212 Posts
Update #2: Stopped by the dealer yesterday and did a test drive with the Vette tech (34 years experience) there. Of course the shudder didn't happen in the short drive we took (I'm guessing because the car was not warmed up), but the guy understood what I was talking about. He said that he would do a "trans shift-sequence procedure" on the car and we could see if that addressed the problem. Anyone know what this is?? He said it was not a software update, but a procedure that allows the car to learn how and when to do shifts. Hopefully, I will get the car back today and get some drive time in before I have to store it for the winter. Stay tuned, sports fans...
Yeah, that information was published in a TSB some years ago. It helps the clutches learn.

After that TSB was issued, GM came out with a way to help the clutches learn without having to do the drive cycle. They could be taught while in the shop, using a computer connection.

I hope what he is doing will help you, but I have my doubts.

Did they ever do the triple flush procedure for your torque converter?
 

·
Registered
Joined
·
99 Posts
They have not done a trans flush at this point. They suggested that after this Fast Learn procedure, I should drive it for a couple hundred miles and allow the trans to learn the shift patterns again. If I am still experiencing the problem after a couple hundred miles, they can entertain doing the trans flush. The challenge will be getting good enough weather to get that drive time in before I need to store the car for winter. We'll see. For what it's worth, the car did shift a lot smoother on the way home tonight.
 

·
Registered
Joined
·
25 Posts
my 2017 Z51 A8 doing similar to what you described. Dealer did the flush procedure - made no difference. 2nd dealer (convenience only ... no issues with other dealer, yet...) did extensive test drive and now believe the problem is in the torque tube installation. Unfortunately, another week before they can get to it.

a few points I notice on mine.
vibration usually goes away after lifting throttle (like downside of an overpass)
often starts on LH curves - but can occur on straights, RH also.
not speed related.

car had the t/c shaft TSB previously

All new tires - balance rechecked.
 

·
Registered
Joined
·
7,930 Posts
500 Miles after Flushing the transmission shudders have gone and smooth shifting.
Dgbenn1964, that is great news that your C7 Masterpiece is squared away for some wheel time.

SF
Rick
 

·
Registered
Joined
·
143 Posts
I experienced the shudder for the first time driving to a show on Friday. My 2016 Z06 is at just over 9000 miles.

It wasn't as bad on the drive home Sunday when it was cooler.

I'll be due for an oil change soon so I will talk to my service adviser while I'm there.
 

·
Registered
Joined
·
41 Posts
Three and 1/2 months later and all is still good.

I took the car in two weeks ago for the shudder and rpm fluctuation problems. The tech and I took it for a test run and it shuddered and the rpm fluctuated. I was in the passenger seat and was able to observe that the fluctuation corresponded with the shudder. I left the car for diagnostics, expecting that the triple flush of the torque converter would be the solution. Not so. Bowling Green told them the torque converter was the problem and to replace it. That is major surgery as the rear bumper is removed and the rear drivetrain is completely removed and put on a bench. Not only does the car now have a new torque converter, it also has new bolts to hold it together and a new cable running to the gear shifter. I suspect the torque converter is a new vintage, i.e. part number. The tech drove it for 50 miles to check it out and all went well. I have it back and it is running better than ever. Thanks to the team at Parks Chevrolet of Augusta for solving the mystery.
 
41 - 60 of 125 Posts
Top