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Discussion Starter #1
Hey Guys,

Wondered if anyone was experiencing the following 2 issues:

1. Ping from Exhaust - I know its common that the exhaust will make a ping sound during cooldown but I can hear my pinging while sitting at stoplights or driving normal. It happens all the time and I crawled underneath the truck it appears to be coming from the muffler. I saw an article where this was an issue in 07 but the dealership told me that GM said this ping was "normal" and not to mess with it. Anyone else have this sound?

2. Downshift from 4th to 1st - I noticed the new 6 speed downshifts hard in town driving situations. Out on the interstate its smooth but when it downshifts going thru different stoplights you can feel it in the cab. The dealership said this was the torque management and that Allison actually builds these 6 speed transmissions similar to the diesels. Any truth to that???

Thanks
 

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Have you ever spoken to Customer Assistance regarding these concerns? I would be happy to look into this further. In order to do so, I will need your VIN and current mileage sent to me via private message. I look forward to hearing from you.

Tricia, GM Customer Service.
 

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Hey smokerace, I recently purchased a 2011 Silverado z71 4x4 and was wondering the same thing on the transmission. I've only noticed that mine, on a few occasions, when I come to a complete stop, all of a sudden you can feel the whole truck jerk forward when the transmission shifts down and almost feels like it is slamming into gear. It kind of concerned me a little but have never looked into it. Was wondering if this was normal?
 

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I just purchased a 2011 1500 LT 4x4, and the 6 speed seems to shift very poorly. It does jerk when coming to a stop sometimes. Also, it seems to hunt around
alot, like it isnt sure which gear it should be in. My truck has 150 miles on it... Hopefully its something that is correctable. Its actually quite annoying
to drive this truck around town like this, but it seems to be a common problem with the 6 speed from what ive read.
 

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rebeals and tawd77,

I would also be happy to look into this further for you as well. Please feel free to send me your VIN and currrent mileage. It may also be helpful to have your name, address, and phone number. You can also contact me via private message if you would like. Thank you in advance.

Tricia, GM Customer Service.
 

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I have noticed the heating/cooling sounds on my 11', it actually made me stop the other day when I got out and shut the truck off. I'm at 2000 miles, and will give it a few thousand more for everything to go through enough heat/cool cycles to stabalize.

I have experienced the hard downshift only once, and I happen to be watching the AFM and it happened during a transition from V4-V8. If you notice, you'll always be in V8 mode when stopped. It is possible that it's a programming thing, or could be a combination of the AFM and 6speed working together in a certain scenario.
 

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Discussion Starter #7
Thanks for the posts guys. I have always been a Chevy man. I got 187,000 miles out of my 2001 Z71 and it didnt shift nearly this hard. For my truck its fine out on the interstate but when you are going to a stoplight around town it seems that it shifts from 4th to 1st so rapidly its like the shift points are messed up or something.
 

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Thanks for the posts guys. I have always been a Chevy man. I got 187,000 miles out of my 2001 Z71 and it didnt shift nearly this hard. For my truck its fine out on the interstate but when you are going to a stoplight around town it seems that it shifts from 4th to 1st so rapidly its like the shift points are messed up or something.
I would have it checked, that does not sound normal, nor I have I experienced it like that. It was more of a hard downshift (like defueling in a diesel), but not like a missed gear.
 

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Did this ever get addressed and fixed? Please update if you can, thanks. :great:
 

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2011 6speed 5.3 4wd--I have this problem,jolting ,clanking when slowing down. complained since day 1 and told its learning and will go away, been to 4 dealers and no help. customer service told me they don't warranty noises which is only part of the problem, its just the extremely annoying one. I can't explain in words how much this has been pis--ng me off,brand new vehicle and I was real clear to the dealer that I'm not having this when it started,I don't want a brand new truck that drives like this." oh just keep putting on miles,it will go away. I truly can't stand this truck,gm has let a long time customer down bad.
 

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2011 silverado Z71 5.3 6 speed 4wd I have a grinding noise in the transmisson when the truck gets to 20 it goes away if I press on the gas but comes back when I ease off the mechanic can hear it but cant tell me 100% if I have a problem or if this noise is normal? Has anyone had this noise?
 

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I guess I'm lucky. I haven't experienced any of those issues. Mine shifts like a dream with one occasional exception....every once in a blue moon (has happened about three times since I bought it in October) I get this Gawd-Awful CLUNK when I hit the gas and then back off. Maybe I'm just catching it when it intended to upshift or something. It's rare but it'll scare hell out of you. BTW, mine's a 4x4, but NOT a Z71. Don't know if that makes any difference.
 

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I got the head of the chevy garage to go for a ride he not only heard the grinding in 4 gear but 5th and 6th as well as soon as I reach cruising speed it starts up. He stated he will look up and check with chevy for any information dealing with this type of noise keeping my fingers crossed!
 
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