Evan Zlock

I have a 2011 Silverado with the same specs. Purchased one March 2011, loved the truck, so much so that when it got melted by my house burning down I called the dealer and ordered an identical truck. They found one spec for spec, so I bought it. Since day one it has exhibited behavior like you have described. In fact the first thing to cross my mind was that the trans feels clumsy and confused. Of course the dealer found no codes when I took the truck in. And refused to even acknowledge the issue. Told me what I thought I felt was the Active Fuel Management system and it was functioning properly. Apparently they forgot that I had recent experience to the contrary. It is typically a subtle shudder and they just said they didn't feel it. Unfortunately my driving style and the roads on which I spend the majority of time allow me to encounter this hundreds of times a day. Bought this truck mid October 2011 now has 15000 miles on it with no noticeable change. Truck is just how it was delivered. To be fair to the dealer I have only complained about this one time. I'm self employed and just now coming into my slow season so I can devote time and effort to this.

Chevrolet Customer Service

<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <wontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]--> Evan Zlock,

Is your vehicle a 2500HD-3500HD? If so, the transmission control module software may need to be updated.

Louis
GM Customer Service

super6

Evan;

sounds like my experience exactly...it is like the tuning on some/most of these is so "OFF" that it makes the driving experience really stink. I continue to have this problem...have since I can remember. I have been in this truck since June of 2010. I have 60K on it now and it still does it all the time. The dealer, unfortunately, just plugs it in and say "well, no codes, so you are fine". I know that. It is not broken. It is not malfunctioning. These 6 speed tranny's just are not tuned correctly. I have been checking into an aftermarket tuner called Blackbear Performance. Seems like they have had great results getting these vehicles to perform properly.
This just makes me more frustrated as an aftermarket company can get the truck to work, but the company that made it can not/will not do anything. This is not acceptable to me. GM Cust.Service has been very professional with me and is doing what they can. On my case, they have gone to the GM engineers...no luck, no "re tune" available. The dealer is no help because there is nothing broken...and they are not set up to retune the truck.
From what I have found it is either a TPS (throttle position sensor)...very unlikely, TMS (torque management system)....this could be it as it is what Blackbear turns off or down considerably, or a Transmission Tuning concern...which has to do with shift points. I have been reading a lot of forums, and apparently this is pretty common (the confused tranny that will not shift correctly as I described above) on the 1/2 ton w/5.3l and six speed. Seems like it is worse on the 3.08, and 3.42 rear ends, which makes sense as it is a bit taller gear to pull for the tranny as it relates to the final drive.
I have hours and hours of my time into this with multiple dealer visits...no help...no solution. I did put a new air filter in, and it seems to be a bit "snappier" pulling through the dead zone of the tranny and the completely gutless range of this engine (1200--2100rpm or so)...when you get past 3k, this thing rocks and rolls...but down low...it totally sucks.
Let me know if you find a solution through your work on this...hopefully GM will come out with a re-tune of this 6speed very soon.
Jake

super6

Louis;

It is not a 3/4 or 1ton...Evan said it is the "same specs" so that would be a 5.3l with the 6speed and a 3.42 rear end.

woogie1667

do u guys still have the original air filter system on your trucks?
because i just put in airaid cold air intake and i don't notice the tranny problems as much. alot more HP. could it be not enough torque from engine????? just a question because i'm not a mechanic

Evan Zlock

Louis, the truck is a 1500. Evan.

Evan Zlock

Jake, what do you mean by aftermarket tuner Blackbear Performance? What do they offer or do to remedy the situation? And yes I agree, this is unacceptable. Evan.

super6

Air Filter: Interesting you mentioned this. I just "re-charged" my K&N Filter...stock filter housing with a K&N drop in. Seems to really have helped A LOT! Still has bog...and I am not ready to make a judgement as to whether or not this is the solution, but seems much, much more responsive. Will let you know after another week of driving.

BlackBearPerformance is a custom tune deal out of California. Justin is the guy who I have been talking with. He is very, very sharp and has tuned over 1000 of our trucks. He knew about everything I was talking about and has a custom tune to fix these problems. It is all over the forums and it seems like guys are very, very happy with how their vehicle is set up after he fixes the bugs in the tranny tuning (and dials in this 5.3l so it performs to its capabilities!). While this is a very awesome way to go, it still makes me mad that the company that made the truck (GM) can't do anything to make it run right, but an aftermarket company can for just a few hundred dollars. This is what I am "shoveling" right at GM and asking, respectfully and forcefully, that they fix it! Will let you know what I find out...check it out at
Black Bear Performance :: Custom Tuning Solutions for 96 and newer GM Vehicles

Jake--MN

super6

Woogie1667;
Yes, I noticed a huge change after refreshing my K&N. Still considering a system like the one you have. Do you get any intake "drone" or noise...much more than stock? Did it take a day or two until your truck "adjusted" to more air, or was it immediate?

woogie1667

yes, it sounds good. it reminds me when we would flip the breather cover over to get that sound on the carb. motors. it also looks like maybe 2mpg increase in fuel mileage (10.8-11.3 to last tank was 12.8)