My RS 1.4 turbo 6 speed auto works great going up through the gears, but it get "clunky" at low speed when automatically downshifting. It sounds loud and has a very detectable feel and shake when it gets to 3rd or maybe 2nd and 1st gear. Turning into my neighborhood from a 50 mph street then braking down to 15 mph to go around a corner and then a little acceleration really makes the tranny hunt and grunt with noises and lurches. Anyone else have this experience?
6 sp auto downshift problem
- Thread starter okcbob
- Start date
I have a 6 speed auto that does the same thing, LT here though, not an RS. Seems to be "rough" downshifting when slowing to a stop aggressively, or slowly, usually "acts up" worse after I drove it aggressively, and seems to stay "worse" for a few drive cycles afterwards until it relearns my usual pattern of "nice" driving, if that makes sense. Dealership told me back when I was at 500 or so miles that the transmission was "learning" how I drive? I'm at 6500 miles now....getting pretty annoyed at this "learning" process.
SonicBoy24
New member
THE PROBLEMS WILL SOLVE THEMSELVES.
As these cars learn how you drive and adapt accordingly, the car will learn to smooth out the shifts. I had this problem for the first three months or so, then it went away.
Also, using Manual mode helps it learn a lot quicker. That's all I ever use when I drive.
As these cars learn how you drive and adapt accordingly, the car will learn to smooth out the shifts. I had this problem for the first three months or so, then it went away.
Also, using Manual mode helps it learn a lot quicker. That's all I ever use when I drive.
ungawd
New member
The answer is: 24lb flywheel. When decelerating, the ecm will stall the torque converter at programmed speeds to downshift. During this stall the tq converter/transmission will slow at a rate greater than the oversized flywheel. After the downshift occurs the torque converter will reengage at an unmatched speed to the flywheel. The only resolution would be to swap to an appropriate mass flywheel. The one we have is most likely dual-mass for fuel efficiency.
DOwnshifting issues
I just purchased a 2012 automatic 6speed chevrolet sonic about a week ago and while gliding to a stop I am experiencing a jerk from downshifting 33 to 28 mph and 22 to 15 mph (2nd and 3rd gears). From what I gather from this forum when I bring this car back to the dealership they are going to tell me this is normal activity. Does anyone else have the same experience? What do I do?
I just purchased a 2012 automatic 6speed chevrolet sonic about a week ago and while gliding to a stop I am experiencing a jerk from downshifting 33 to 28 mph and 22 to 15 mph (2nd and 3rd gears). From what I gather from this forum when I bring this car back to the dealership they are going to tell me this is normal activity. Does anyone else have the same experience? What do I do?
Blue hedgehog
New member
How many miles on your car? Mine seemed to slow down rather quickly when new and downshifted harder probably due to the engine still breaking in.
24lb flywheel on a automatic?
Autos have a flex plate or sometimes called a drive plate that the torque converter is bolted to. The torque converter is the heavy rotating mass on the back of the crankshaft. Flywheels are on manuals.
Blue hedgehog
New member
I'm at 19k. I'd say the 1st 4-5k it was a lot more deceleration than now. I know with the decel fuel cut off these cars slow down a lot faster than older cars that didn't have dfco. Next time I go out for a drive I'll try to pay attention to the downshift rpms and get back to you. It may be the computer hasn't learned your driving style yet. Maybe that's the normal downshift points I have no idea.
Chevrolet Customer Care
New member
snap0803,
Are you still experiencing this concern? We can certainly have your dealership reach out to you in regard to this concern. Please private message me your name, VIN, phone number, and dealership name.
Erica Tiffany
Chevrolet Customer Care
Are you still experiencing this concern? We can certainly have your dealership reach out to you in regard to this concern. Please private message me your name, VIN, phone number, and dealership name.
Erica Tiffany
Chevrolet Customer Care
Blue hedgehog
New member
I wasn't able to get numbers coasting to a stop from 6th-1st due to too many people on the roads. But here's what I have.
6th-5th=41
5th-4th=28
4th-3rd=18
3rd-2nd=15
2nd-1st=9
I can feel the 6-5 5-4 and 2-1 downshifts. The 4-3 and 3-2 shifts I had to put it in manual mode and watch the numbers to tell.
Also mine doesn't downshift till the rpms drop below 1200 in the higher gears. Lower in the lower gears
6th-5th=41
5th-4th=28
4th-3rd=18
3rd-2nd=15
2nd-1st=9
I can feel the 6-5 5-4 and 2-1 downshifts. The 4-3 and 3-2 shifts I had to put it in manual mode and watch the numbers to tell.
Also mine doesn't downshift till the rpms drop below 1200 in the higher gears. Lower in the lower gears
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Mine is exactly the same. the shift at 28 mph is the most pronouced jerking motion. almost as if the transmission isnt catching at the same speed as the engine
Hey guys,
Any time I coast to slow down or stop, my automatic will downshift which jerks pretty uncomfortably a couple of times before coming to a stop. I think it's around 26 MPH and then a 2nd time before the stop.
If I put it in Neutral and coast to a stop, it's perfectly smooth and comfortable. Is there something wrong that the dealership can fix? I hate how hard it jerks when slowing down. It makes it impossible to drive smoothly and comfortably. Thanks!
Any time I coast to slow down or stop, my automatic will downshift which jerks pretty uncomfortably a couple of times before coming to a stop. I think it's around 26 MPH and then a 2nd time before the stop.
If I put it in Neutral and coast to a stop, it's perfectly smooth and comfortable. Is there something wrong that the dealership can fix? I hate how hard it jerks when slowing down. It makes it impossible to drive smoothly and comfortably. Thanks!
Chevrolet Customer Care
New member
Hey there,
I apologize that you are experiencing these concerns with your Sonic. If you would like any assistance into the dealership, please feel free to let me know in a PM. Hope to hear from you soon!
Patsy G
Chevrolet Customer Care
ChrisJ
Active member
To those who keep critizing and jumping on people for calling a flexplate a flywheel, I hope you have never called a part of a car a drive shaft as its technically called a propeller shaft.
I also hope you never called something a wheel well on the back up a pickup as it's technically called a wheel house. And to those who keep saying gas pedal, it's an accelerator pedal! I've heard people refer to the center support bearing between two propeller shafts as drive shaft hanger bearing, and a generator is an alternator, and the rest of the world started calling condensers capacitors in the 1950s. Flexplate, flywheel, whatever. The round disc thing that connects to the crankshaft hub?
So now with that said, let's do like others have in the manual threads.
OMG the transmissions a piece of junk! When will GM fix this!?!?
Just in case no one got it, that was sarcasm. The 6 speed auto is a fine trans, it may have occasional hiccups but I believe the failure rate is extremely low.
I also hope you never called something a wheel well on the back up a pickup as it's technically called a wheel house. And to those who keep saying gas pedal, it's an accelerator pedal! I've heard people refer to the center support bearing between two propeller shafts as drive shaft hanger bearing, and a generator is an alternator, and the rest of the world started calling condensers capacitors in the 1950s. Flexplate, flywheel, whatever. The round disc thing that connects to the crankshaft hub?
So now with that said, let's do like others have in the manual threads.
OMG the transmissions a piece of junk! When will GM fix this!?!?
Just in case no one got it, that was sarcasm. The 6 speed auto is a fine trans, it may have occasional hiccups but I believe the failure rate is extremely low.
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Sneakerfix
New member
Mines failed this past week wave plate is the issue from what my dealer said it's a issue with other GM transmissions. Picking it up tomorrow also it's a 2011 cruze
