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Chevy Silverado and GMC Sierra Transmission Problems



  • my 2011 silverado is a constant disappointment. from the shotty brakes to the diff that has metal in the oil and locks up, and the bedrails the dent from falling acorns in my driveway.
    my first car was a 1966 el camino and Ive owned a chevy ever since.
    I will never buy another gm product.... today I was accused of being racist by a cheverolet costumer service agent, when I said that I was having trouble understanding him due to his non english accent. I was blown away! I have more but figure gm doesnt care they already got my $44K
  • Sorry to hear of your trouble. It's been two months since my 2011 transmission was repaired. I got to say I'm very lucky the mechanic who repaired it knows his business. I've had no problems so far "Knock on Wood" but also I understand two {2] does not make a "Star". The tranny does shift better than before with no hard down shifting that a lot of people complain about. I have a 6.2 lt engine and when you stomp on it the transmission response like you want it to. I agree GM needs to get people that can speak English. If that's being racist then so be it. Good Luck but I still wouldn't buy the new eight speed Dodge
  • Welp, looks like I got a bad one. less than 500 miles, I bought a rolling piece of crap. 2013 6 speed with 5.3. It's like mr. toads wild ride at disney land, and yesterday it almost got me killed.. when it lagged on acceleration.. I believe this is a TERRIBLE safety hazard.
  • I gave up on my 2011 GMC Yukon, here's what you do: Take it back to service three times, make sure your service receipt states clearly that you brought it in for shifting and acceleration problems. They will tell you the same thing they tell everyone's normal!!! Then call your local lemon lawyer and let them take over, oh yeah.....if you continue to drive your truck don't forget to increase your life insurance.
  • bolo100bolo100 Posts: 1
    i get the same in my 2012 silverado crew cab 1500 exactly the same worries me a bit and now i wanna bring this up with the dealership i bought it from u have any success in finding anything out with whats wrong with the truck?
  • gmcustsvcgmcustsvc Posts: 4,251
    Good morning bolo100,

    We see you're planning on visiting your dealership to get this looked into. Please keep us updated on your progress there, and if you should need anything don't hesitate to contact us via email at (include your name and contact information, the last 8 digits of your VIN and mileage, and a summary of the situation).

    Sarah, GM Customer Service
  • I want to thank everyone for the info. I read every post on the GM trans issues. I was going to trade in my 99 Silverado for a new one. But after that forget it. I broke something in my rear end today . I will be fixing it. And i am going to pick up another old 67 69 camaro. Back when they made good cars. I spent my life perfecting the best show car paint jobs money can buy. And i am going to go back to driving the old cars full time. The wife and kids of course will keep driving the Nissans or BMW. I never have any troubles with them. American corporations have sold out to China and everything that comes from there is nothing but junk. And that is what is on most of these American made car's. Before i read your post my problem was how they justify the money they want for a new truck when they are paying 50 cents an hour for the parts on it. Again thanks for the heads up.
  • chuck1chuck1 Posts: 1,405
    Your right - doemestic manufacturers haven't made a decent car in the last 40 years or so......:)
  • ashlegashleg Posts: 1
    A few months ago, the transmission felt like it was slipping and wouldn't shift from 1st or 2nd. It would only happen occasionally and got worse as time went on. We took the truck to a transmission shop where they replaced the solenoid and a couple of other things and sent us on our way. Worked fine for a couple of days and then occasionally wouldn't shift. $400 and a week later we were right back where we started.
    Took it to a different transmission shop where they felt the ignition switch was faulty. Replaced it, and then they thought it was an issue with the computer. The shop replaced a number of parts including the computer and as it stands we have spent 1400 on fixing this issue and now it's not starting. The infuriating thing is that almost definitely tomorrow, it will start perfectly. I do believe the people working on it are trying to fix it. The intermittent and changing problems that began with the non-shifting transmission seem to really have them stumped. If this sounds like anything someone has seen, I'd appreciate any input. I realize it's an older truck but we would like to keep it if we can.
    Thank you in advance for any thoughts.
  • chuck1chuck1 Posts: 1,405
    The transmission issue is normal. The dashboard going out is not. The six speed transmissions are not the most smooth shifting transmission. However, this hasn't affected reliability.
  • dthatcherdthatcher Posts: 8
    First of all a 13 years truck having a tranny problem can't be uncommon.t Try having a 2011 (with only 25K) with a tranny problem like I had!!!l It's obvious whoever you have been using don"t have a clue no matter how hard they try. Some times you have to bite the bullet and take it to a dealer an bent over a little to find out what's going on ( can't believe I'm saying this). Your now out 1400 dollars and it sounds like your in worse shape. My suggestion is have a dealer or some other transmission specialist take a look since it's sounds like you have been taking it to Mom and Pop shops. Trying to save money by going here and there usually back fires ( especially on big items like a tranny) I feel your pain but it sounds like a total replacement that comes with a warranty is needed to take care of this matter once and for all.
  • bim38bim38 Posts: 1
    At times it is very difficult to put my truck in "Park". Its seems like the vehicle has to drift an inch or two before I can put it in "Park". I'd like to see if anybody else had this problem. I haven't tried replacing anything yet. Could it be the neutral safety switch or the parking pin in the tranny?
  • jjacksjjacks Posts: 16
    FYI, anyone reading this should go back and look at my experiences with this problem. A GM area rep of 20 something years was fired over my deal. GM gave me 3500 (if i recall correctly) to trade in my '11 to get a '12. Some of the problems the '11 had (the vibrations and the rear gear whine) are not present in the '12, but I'm here to tell you that the 6 speed trans has fatal design flaws that WILL ALWAYS MAKE IT SHIFT LIKE [non-permissible content removed]. They are sprag-less, they have clutch-to-clutch shifting, and the electronics are lacking. Downshifts involve precise timing of clutch packs releasing while others engage (as do upshifts although there is enough slippage to mask the 'jerkiness'). This is done with solenoids re-directing trans fluid. The problem is that the transmission doesn't know when one clutch pack is fully released before another is engaged, thus there is 'overlap' of two gears trying to be engaged at the same time....hence the jerky, lunging, speed-up feel. When the viscosity of the fluid is thicker, ie when it is colder, the transmission will act more stupid because the rate at which the fluid evacuates the clutch packs is slower....which means another pack is engaging when the other is still engaged to some extent.

    As far as the gear searching at 45, or any other speed for the matter, that is a product of programming. Contrary to what they will tell you, the transmission doesn't 'learn' anything. That irritates the fire out of me. The transmission selects outcomes from a preprogrammed set of input data......your driving style hasn't got squat to do with junk driving characteristics of the transmission.

    The transmissions can't be fixed. It can be 'helped' a bit with programming. The only thing that will fix this transmission is an internal re-design of the hard parts.

    And fyi, the 6 speed does not get any better gas mileage than the 4 speed. If anything, it's worse.
  • rchs1958rchs1958 Posts: 1
    hello, my truck when you slow down to turn, around 10 mph, then step on the gas, it feels like the transaxle, hits hard, is this caused by the transmission shift patterns, the dealer says, it is learning , my driving patterns, Really at 10,000 miles, is this a programing issue, the engine is a 4.3 it up shifts and down shifts great, just annoying to turn and stepping on the gas, worried this is going to affect u joints or the rear end
  • chuck1chuck1 Posts: 1,405
    Put Amsoil transmission fluid in (better cold performance) and buy one of these-

    The AFM is part of the reason for the jerks. Get the one that will keep it in V8 mode.

    It will make your truck more pleasant to drive.
  • bigman55434bigman55434 Posts: 22
    Apparently my last post with one swear word in it was too much for the moderator, and my post got deleted. Sorry for being too "descriptive" of what I think of GM transmissions. Anyway, I will reiterate what jjacks says. I think he is spot on. On top of all the jerkiness, I have experienced situations where the transmission on my 2011 Sierra 1500 failed to upshift from 1st to 2nd, and then slammed into 3rd. I am also convinced all the programming to manage torque (aka torque management) makes overall driveability worse, because it affects both the transmission and the throttle input (regardless of what my right foot is telling the engine to do). I will gladly take a pre-2007 GM truck over anything made today. I have 1200 miles on my 2013 Sierra 1500 now, and aside from the axle bearing GM forgot to install in the right front axle, which destroyed the axle, axle tube, and seal, my drivers side door panel squeaks and creaks every time I touch it. There is also some weird harmonic when I turn at more than 20mph (like an exit ramp). I think quality control has gone way down as well as the engineering. GM better get its act together soon.
  • dthatcherdthatcher Posts: 8
    You buy a 40K plus truck and it does get personal when you can't get it fixed!!!!
  • cronic94cronic94 Posts: 1
    edited May 2013
    I have a 2005 Sierra 180000 miles transmission shudders in 3-4 gear. Watching the tach the RPM's go up slightly when the shudder happens. Fluid looks clean would this be a mechanical problem or a solenoid . When using the tow switch it doesn't have an effect on the problem.
  • gopogopo Posts: 1
    Wow...I hate reading this. I just bought a preowned 2011 GMC Terrain with the 6-speed transmission. Im experiencing the same exact issues as you and I also feel like horrible programming is one of a few issues here. Hopefully a ECU update can atleast even things out a bit. If not I'll have to look for a custom tune. I really wish GMC would remedy this!
  • There is nothing wrong with the 6L80/90 transmissions. They are light years ahead of the old 4l60e's. Perhaps you got a lemon. Or perhaps you are trying to fix something that isn't broken. Some suggestions for a 'fix' are not a good idea. Don't use a non GM spec oil to "fix it"... GM Dexron VI oil is designed for the six speeds and is good for 100K miles in normal service (50K miles for severe conditions). The suggestion to use a 'tuner' (re-programmer) to change the AFM and transmission computer is also a poor recommendation. The use of a tuner will instantly void the 100,000 mile drive train warranty.

    They do shift a bit hard when new and they do 'learn' driving style, but are biased for fuel economy. If you suddenly change the way you are driving... the transmission will be confused and shifting may be erratic. To force the computer to relearn your style, disconnect the battery for at least 30 minutes. It took at least 20K miles for the shift quality to smooth out on my 2010/5.3L. My only complaint with the transmission is with the way manual mode works. I think GM needs to re-think the way they do manual mode and let the driver force the transmission to start in 2nd or 3rd for snowy conditions. But that is a minor annoyance. Overall, I am quite happy with my 2010 Silverado and would buy it again.
  • bigman55434bigman55434 Posts: 22
    Nothing wrong with the 6L80/90 transmissions? Really? That's a BOLD statement to make when you have nothing to refute what everyone is observing. If there was nothing wrong with my 2008 Sierra's transmission, why did GM give me $3k in buyback money (aka Purchase Assistance) towards my next truck? Why is it that my 2011 Sierra completely failed to upshift from 1st to 2nd, on a level road, 70 degree day, and light throttle input? It revved past 4000 RPM's before it SLAMMED into 3rd or 4th gear. It did that twice in a row before it started sorting itself out. As for learning mode, my transmissions have all shifted better when they were new. They seem to get worse as time goes on. It does not take 20k miles for learning mode to work. Its a few hundred at most. The problem with these transmissions, for the most part, is the horrible TCU and ECU programming. In an attempt to manage torque and get these tranny's to last 100k miles (for the warranty), they have ruined driveability.
  • The problem you had with your 2008 Sierra is irrelevant to the discussion of the current transmissions. The transmission in your 2008 was a 4L60e and has absolutely nothing in common with the 6L80e that was first installed in the Sierra/Silverado in 2009.

    A little "googling" turns up few complaints with the reliability and durability of the 6L80e/90e transmissions, in fact, most, who are knowledgeable about transmissions, think they are excellent.

    As long as the transmission and computer in your 2011 Sierra are stock and unmodified, I am sure that GM will take care of you.
  • chuck1chuck1 Posts: 1,405
    The Amsoil transmission fluid is actually better than the GM new Dexron 6 because it is A FULL SYNTHETIC. GM has never claimed the new Dexron 6 is a full synthetic. In addition, the Range Technology product is a box that plugs in to the OBD port and sends a MESSAGE THROUGH THE ECM but DOESN'T OVER WRITE IT.

    The range technology product turns off the AFM and all reports states it takes the clunkiness out of the powertrain.

    Let's face it-the torque mgmt, the AFM, and the poorly designed 6 speed transmission takes a lot of pleasure OUT of owning this vehicle.

    I know, I own one.
  • I'm sure Amsoil transmission fluid is a fine product, but until it is Dexron VI certified, I won't use it.

    Thanks for enlightening me about the Range Technology product. I thought it was a tuner, but I see now that it just fools the computer and locks out AFM via the OBD port. I can do the same thing by putting the transmission in M5.

    I must not be as demanding as you are... I like driving my Silverado.
  • hblackhblack Posts: 1
    I have a 95 1500 silverado. When I first drive it the transmisson shifts just fine. After about 10 miles if I ever stop and go again it will not shift out of 2nd gear. From that point forward it remains in 2nd gear even when taking off. Once it cools down it will shift through all the gears again. I've replaced the computer box behind the glove box and also changed the ignition switch. I was advised that sometimes a worn ignition switch will not power up the part of the computer that tells the trans to change. Any ideas??
  • chuck1chuck1 Posts: 1,405
    You can do the same thing by putting it in "M5". But with the Range product you get the sixth gear back.

    I am sure you are aware that "certification" means paying a fee to GM to become certified and then a Royalty for each quart sold. In addition to the standard tests.

    I am not an engineer, but I would venture to say the Amsoil meets or exceeds GMs requirement as the product is already formulated. If you browse other forums online-many Silverado owners are reporting good results and improved powertrain smoothness with the two products I mentioned above.
  • My point is that every 6 speed truck transmission GM has made since 2006 has exhibited the same poor driveability, clunky shifts, and missed shifts. They need to fix it.
  • chuck1chuck1 Posts: 1,405
    They are using the same transmission in the 2014s. I am hearing the shift to 4cylinder mode is smoother as is the transmission.
  • tooheeldrivetooheeldrive Posts: 17
    edited June 2013
    That is just an absurd statement. You need to get (your transmission) checked out.
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