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I had that happen the other day--I think the A8 got confused and couldn't decide if it should shift up or down.
On occasion when coasting up to a stop at about 10-15 MPH then applying light throttle had my A8 make a very jerky sudden down shift to 1st gear. It has happened more than a few times, and feels like it gets caught between gears. Engine starts to rev up and then suddenly it drops to 1st gear. I have 19,000 miles on my car and this just seems to be an idiosyncrasy. I wonder if others have experienced this?
Unfortunately I think what you are experiencing is "normal". I fall back on that old joke about telling the doctor that when I move my arm in this way it hurts and he says, so don't move your arm in that way. You know what makes it happen, don't do it.
I drove a manual for a few years in traffic and I found it gets old (I know, I know, this is sacrilege for some people...)
The performance of the A8 is simply amazing, and the bark that comes from a shift at 6500rpm in Sport mode has brought many surprised gasps from my passengers
Guess you are referring to Spring Mountain when you say "they said"
I've been looking for the appropriate place to voice my complaint with the paddle shifter. Maybe this is not it, but here goes.
Unless you never move your hands from 9 and 3, how the hell can you actually use the paddles when on track or in an autocross?
I think these paddles were driven by Marketing playing keep up with the Joneses, just like they did when they pushed "drilled rotors" on the C6Z.
A much more useful shift mechanism would be a floor mounted shifter that has a gate allowing a forward or rearward bump to make the shift. I know where that shifter is. the paddles are hard to locate and I've even bumped an upshift accidentally.
I'm not a newbie. Autocrossing since 1965 and road racing since 1989.
Other than this, this car is incredible. Looking forward to July 4 when I can take it to Waterford Hills and do a direct A-B to the C6Z I ran there last year.
You have more experience than me but I just learned this past weekend to shift when the wheel is straight. Or at least when my Hands are at the 3/9. Up or down keeps the car balanced. I was trying to shift coming out of turns and could not find the paddle with the wheel turned, esp those 180's. I now up shift once the car is pointed at the next gate again getting my hands back to 3&9. I also learned to downshift at the same time I'm braking before entering a turn, again, it helps to balance the car. The z51 is a monster autocross car.
I created this thread last year and most didn't seem to understand the benefit of having a manual mode on the shifter as well as having paddles. I can't understand why the ATS has this feature on the same A8 transmission but not on the flagship GM sports car. It cannot cost much more money or add much weight to include this existing GM feature into the Corvette.
On occasion when coasting up to a stop at about 10-15 MPH then applying light throttle had my A8 make a very jerky sudden down shift to 1st gear. It has happened more than a few times, and feels like it gets caught between gears. Engine starts to rev up and then suddenly it drops to 1st gear. I have 19,000 miles on my car and this just seems to be an idiosyncrasy. I wonder if others have experienced this?
Hi sharpseadog,
Unfortunately, we are unable to speculate if this is a normal operation as we are not technicians. We can suggest contacting your dealership and bringing this to their attention as you are still under warranty. If you would like our assistance in reaching out to them, please let us know. We are happy to assist the best way possible!
My Corvettte has been at the dealer two weeks come Friday. It's the second time it's gone in for a stutter while it'sin V4 mode. The last time I took it in they told showed me a TSB and said it was normal. I know it's not normal as it's a definite hickup that occurs every two seconds or so while in V4 mode which is very intrusive and annoying. They called me last week and again tried to tell me it was normal.
I went over and took it out with the service manager, not a service writer, and put it in V4 on cruise at about 57 mph. Sure enough ever two seconds it feels like the car looses forward momentum. I'ts almost like an engine miss, except the engine sound doesn't change and it doesn't do it in V8 mode. The service manager acknowledged it shouldn't do it and it was annoying, but he had no clue what could cause it. I think it's the A8, but we'll see.
Only have ~800 miles so far on my A8 but I'm really impressed with it. The upshifts at WOT are one of those things in life that everyone should experience at least once, IMO. Totally diabolical
I have done 8 track days and car overheated every day (A-8). Only went into limp mode two times on hot day but power steering quit. Dealer installed a new vent under the car for the electric power steering motor (ISB), if you have this problem. Not nice feeling to have the power steering quit on track! My 2016 C-7 overheated on days where the temperature was below the quoted 86 degrees (e.g Laguna Seca and Sonoma). I drive the car 300+ miles to/from the track with NO problems what-so-ever! GM needs to make upgrades available through ISB's to backup their claim that the C-7 is a trackable car.
On occasion when coasting up to a stop at about 10-15 MPH then applying light throttle had my A8 make a very jerky sudden down shift to 1st gear. It has happened more than a few times, and feels like it gets caught between gears. Engine starts to rev up and then suddenly it drops to 1st gear. I have 19,000 miles on my car and this just seems to be an idiosyncrasy. I wonder if others have experienced this?
I will answer this when I pick up my car, hopefully next week. It has been at the dealer since Sep. 1 when I took it in for a fuel leak. Since they had to drop the tranny they were supposed to perform the TSBs related to the check valve and torque converter.
I will answer this when I pick up my car, hopefully next week. It has been at the dealer since Sep. 1 when I took it in for a fuel leak. Since they had to drop the tranny they were supposed to perform the TSBs related to the check valve and torque converter.
Hope they get you back on the road soon. Ever since I read your posts on the fuel leak I could swear I smell gas in my garage. But there are two other cars in there so who knows. I think its just me being paranoid, I hope. Having a gas hot water heater in the garage I'm a little paranoid about fumes..
Hope they get you back on the road soon. Ever since I read your posts on the fuel leak I could swear I smell gas in my garage. But there are two other cars in there so who knows. I think its just me being paranoid, I hope. Having a gas hot water heater in the garage I'm a little paranoid about fumes..
For sure. Gasoline vapors in a closed garage with an open flame is not a good situation. From what I understand there was a run of cars with defective fuel pumps or seals. Can't confirm if this is true.
For sure. Gasoline vapors in a closed garage with an open flame is not a good situation. From what I understand there was a run of cars with defective fuel pumps or seals. Can't confirm if this is true.
There has been a few C7s on the forums now with fuel leaks, one was just built and delivered recently so I dont know if its a pattern or just random vendor QC issues/crap parts.
Time will tell I guess on the fuel leak, hopefully they get your trans straightened out. Knock on wood my A8 has been OK for 5K miles (july '15 build).
the A8 would have been acceptable in the later C6 generation cars. At WOT the A8 is great..quick snaps into gears but that's where the positive feedback ends...
Around town, or using the A8 paddles the car feels lethargic. No flame suit on here. Anyone who hasn't tried the ZF 8 speed in a Chrysler product, BMW or Jaguar needs to before challenging my statements. By comparison the A8 is dog poo and is the weak link in a fantastic drivetrain.
The Zf 8 speed has proven you certainly dont need to go dual clutch to have a great automatic all the time
Dads C7 with the slugish, confused at times A8...Zf8 Speed in the Jag is damn near flawless.
Last edited by NiteriderFRC; 09-24-2016 at 02:42 PM.
I have just under 7k miles on my '16 Z51 with about 250 miles being track miles over 3 days - 1 in May and 2 this month. Temps were in the 70's both days and I did add the Z06 intake scoops for whatever additional air flow that may provide.
I have had no overheating problems and the A8 shifts great on the track. I have tried the manual mode and the auto-performance shifting mode. The instructors at Spring Mountain provided excellent instruction on driving/shifting the A8 in manual mode, so that's all I use on the track now.
The only issue I notice on mine happens when I first pull out of the driveway with the 1-2 shift hanging up a little. Other than that, no problems. True, in normal driving the tranny feels/shifts like any sedan and I would prefer a much more firm shift, but I'll live with it.
When we had a Mustang with an A6 I had a custom tune put on it and the guy who did had the shifts firm enough for it to grab some rubber shifting into 2nd & 3rd under hard acceleration. If GM won't do it, perhaps a custom tuner could on the C7 A8. Of course that would probably void the warranty.
I had a 2015 Scat Pack Challenger with the ZF 8 speed auto and it is was a much better trans than the C7 A8. I'm sure the ZF in the Jag is the same. At least as far as just driving around town, at WOT the C7 A8 works decent, but it has a lot of low speed weirdness. Hard to find fault with the ZF, rock solid and really fun with the paddles even at lower throttle and RPM.
A lot has to do with trying to get fuel mileage numbers up too. I also liked that once you put the Challenger in sport or track mode it shut off the cylinder deactivation. It would be nice to be able to shut off the V4 stuff on the C7 without an aftermarket tune or the battery killing range device.
Originally Posted by NiteriderFRC
the A8 would have been acceptable in the later C6 generation cars. At WOT the A8 is great..quick snaps into gears but that's where the positive feedback ends...
Around town, or using the A8 paddles the car feels lethargic. No flame suit on here. Anyone who hasn't tried the ZF 8 speed in a Chrysler product, BMW or Jaguar needs to before challenging my statements. By comparison the A8 is dog poo and is the weak link in a fantastic drivetrain.
The Zf 8 speed has proven you certainly dont need to go dual clutch to have a great automatic all the time
Dads C7 with the slugish, confused at times A8...Zf8 Speed in the Jag is damn near flawless.
06-15-2016, 06:40 PM
Unexpected down shifts
