Last post on Nov 19, 2013 at 10:09 AM
You are in the Chevrolet Silverado & GMC Sierra
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Chevrolet Silverado 1500, Chevrolet Silverado 2500, Chevrolet Silverado 3500, GMC Sierra 1500, GMC Sierra 2500, GMC Sierra 3500, Transmission, Truck
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#1341 of 1521 Re: 07 silverado 1500 classic transmission shifting thump b/w 1st & 2nd [lm69000miles]
Oct 29, 2012 (10:46 am)
Good afternoon lm69000miles,
We're sorry to hear that you are having troubles with your Silverado. It looks as though you may already have started a Service Request with us, but if you haven't and if you wanted for us to get one going for you please contact us at socialmediagm.com with more information (including your name and contact information, a summary of the situation, the last 8 of your VIN and mileage, and the name of your dealership).
Sarah, GM Customer Service
#1342 of 1521 2012 Sierra Silverado Buyer
Nov 01, 2012 (5:40 am)
New GM 5.3 liter 6 speed truck buyer; make sure you test drive these trucks extensively at 45 mph on level ground. Not just a normal test drive. Make sure you take it out for a while.
-Place the display on Active Fuel Management (AFM) mode (display shows movement from 4 to 8 cylinders) and determine if the truck growls, lags and may even occasionally bang when switching from 4 to 8.
-Check for slop/slash in the rear end as you slow to turn a corner. Especially to the right for some reason! As you step on the gas, see if the truck lags, then "catches" and lurches.
-Ask the salesman if there are any internal GM service bulletins regarding the 6 speed transmission with AFM.
I you're going to do alot of driving like I do (in town and out of town) between 40 and 50 mph, make sure you test drive these trucks at that speed.
My 2011, like other 2010's and 2011's, is incredibly annoying to drive. Worst part, GM knows it.
DON'T LET THE SALES MANAGER TELL YOU IT HAS TO ADJUST TO YOUR DRIVING HABITS.
TEST DRIVE IT!
#1343 of 1521 Re: CRAPPY TRANSMISSIONS [obyone]
Nov 01, 2012 (10:12 am)
At first, the 2011 didn't seem like it had all the horrible tendencies of the 2008, but it does, and worse. I got a screaming deal on the 2011, including $3k in buyback assistance, and about $9800 in other incentives (off dealer invoice, not sticker price). As of today, with 10k miles on my truck, I can trade it in for what I paid for it. I am just waiting for GM to address the problems. From a stop, the truck shifts fine when going 0-60. All of the problems are at 45mph and slower. Downshifts take max throttle input, which I can live with. The worst of it is getting on and off the throttle in slower traffic. The tranny seems like it is fighting itself, loading up, slamming in and out of gears, and always wants to push me into the vehicle in front of me when slowing down. I don't know if it is a software or mechanical issue, but it is dangerous in my book. I will not have this truck past the 3 year 36k warranty. Some of the shifts are so bad, I wonder if a u joint is going to snap. Then try driving it cold (ambient temp 32F). Everything is magnified 10x.
#1344 of 1521 Re: CRAPPY TRANSMISSIONS [bigman55434]
Nov 01, 2012 (11:01 am)
I don't know if it is a software or mechanical issue, but it is dangerous in my book.
The torque converter spends as much time as possible "locked" when it's in gear. That's what you are feeling. The brakes work when applied.
#1345 of 1521 Re: 2012 Sierra Silverado Buyer [ceb66]
Nov 01, 2012 (11:08 am)
GM truck buyer, please know "ceb66" has a personal vendetta against GM and doesn't like some of the normal operating parameters of his truck. For example, if you put the truck in manual mode gear 5 around time, it doesn't display those characteristics at all. Besides, who wants any vehicle shifting in to 6th gear around town. Unlike some manufacturers, GM actually gives you away to avoid this. Also, check check out cebs66 hundreds of other posts where he says the same thing over and over and over again. He thinks if the post count under this topic reaches some miracle milestone GM will buy back his truck.
#1346 of 1521 Re: CRAPPY TRANSMISSIONS [chuck1]
Nov 01, 2012 (12:26 pm)
"The torque converter spends as much time as possible "locked" when it's in gear. That's what you are feeling. The brakes work when applied. "
I never would have guessed that brakes work when applied. And yes, I understand that the converter is programmed to lock up as much as possible. HOWEVER, the converter should NOT be locked at low speeds, like below 25MPH, and it should NEVER be locked when I am trying to stop and am at a slow speed. Even with the brakes applied, I can feel the transmission still trying to push the vehicle forward, and it fights the brakes. If the stupid thing would just uncouple and coast, problem solved. The tranny waits until the last possible second to downshift, forcing the RPM's up to keep the truck from stalling, and as the slush box finally drops to first, the ECM can leave the throttle alone. I have seen the tach drop to 300 or 400 RPM's when coasting to a stop, and due to the fly by wire throttle, the computer determines that it needs a bit of throttle to keep from stalling. This is what I am talking about. Solenoids are sticking in this transmission, or are very poorly designed.
#1347 of 1521 Re: GM Truck Clunk [ceb66]
Nov 01, 2012 (12:37 pm)
ceb66 is 100% right on the driveability issues with the late model GM trucks. Aside from the shifting problems I already mentioned, at around 40-45mph and a steady cruise, I can watch the tach, and it's like the tranny slips or almost starts to come out of lockup. The tach needle spikes up about 100-200rpm at least once every few seconds. I can feel and hear it driving, too. I haven't really noticed any issues with the AFM, unless this is it. I just know that every GM truck I have had since my 2005 Sierra Denali 4 speed has shifted far worse than the 2005 and prior gas trucks I have had (the exception being the two Duramax's I had, which were 2006 and 2011 models, which had awesome Allison tranny's). Ever since around 2007, they went to the fly by wire throttle, and I just don't think the ECM and TCM do a good job of working together. I can't believe that GM all of a sudden can't make a tranny that works properly. I want to believe it is a software issue, whether intentional or not. All I ask is they FIX IT.
#1348 of 1521 2003 Silverado 2500 diesel - allison trany
Nov 01, 2012 (5:36 pm)
transmission or transfer case started acting up today - 3 times while driving on highway the engine revs up, speed drops and there is a loud grinding sound from the transmission area - sounds like shifting a manual transmission without the clutch and not getting the gears engaged - stopped the first time and made sure the transfer case manual shifter was in 2 wheel high and it was - the next two times let off the throttle and noise stopped and normal operation returned - not fun when cruise control is on - fluid levels are good - no trany problems before this - occurs when vehicle goes over small bumps on interstate highway - will check the fluid in the transfer case for metal filings and check the shift linkage but not sure where to go from there - any ideas?
#1349 of 1521 Re: GM Truck Clunk [bigman55434]
Nov 01, 2012 (6:07 pm)
To arrive at the EPA mileage GM programs their trans. The dealer can override the shift points (so can some of the performance programmers) to solve your driveability issues. The problem with the dealers programming is that once their tech 2 is disconnected you will lose the shift points. That leaves you with an aftermarket programmer which runs between $300 and $500. Whether it's worth the money or not is your call. GM will not approve a reprogram as it will alter the mpg which is posted on their trucks nationwide. And yes I agree with you it sucks.
#1350 of 1521 Re: GM Truck Clunk [bigman55434]
Nov 02, 2012 (10:49 am)
Don't get distracted while driving, however, switch your driver display to "Instant Economy". Watch and feel it in the mid 40's! The annoying lag and growl will coincide with the 5.3 liter 6 speed awkardly trying to figure out "should I be in 6th at 45 mph, or 5th or maybe 4th. 4 cylinders? Maybe 8? Wait a minute, I'll just pick up the slop and BANG"!
The Feds upped the CAFE standards right after the $54 Billion "bailout" (TARP).
Hmmm? General Motors tweaked these things to squeeze out mileage. They appeased the Feds and still haven't paid back the "loan"(to tax payers).
GM kissed.... and politely went along with the CAFE increase (which the car manufuacturers rarely if ever do) and we got stuck with a very confused computer-controlled powertrain/drivetrain combo.
Be prepared. They're pushing for higher CAFE standards in 2017 (I believe in the 40 MPG range!). That means more hoaky tricks to appease. I've had many GMs. This may be it.
Hopefully nobody else gets stuck with one of these things like I and others have.
Thanks GM. You should be proud. You've made the Federal Government happy.