Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Chevy Silverado and GMC Sierra Transmission Problems



  • VIN# 1GTR2WE78CZ244313

    Fred Beans GMC, Doyelstown, Pa.
  • gmcustsvcgmcustsvc Posts: 4,003
    Please keep us updated on what happens at the dealer. I look forward to your response. Please fee free to email me directly.
    GM Customer Service
  • super6sierrasuper6sierra Posts: 6
    edited March 2012
    Original post:
    "I have a 2009 with a 5.3l, 6speed, 4x4, 3.42 rear end. It came with the Z71 package and has the 18" wheels. I have been having problems with the transmission and I am wondering if anyone else has experience similar problems. 55k miles.
    Here is what happens.
    When I pull away from a stop, it shifts very, very quickly (under normal driving, when I hammer on it, this doesn't happen) down into 2nd and third goes to 2nd before I even make it through the light. So, when I want to then bring it up to speed, it is already locked down into usually 3rd and wants to stay there unless I go past probably 3/4 throttle, at which point it jumps down violently to what feels like 1st. Seems like it is tuned very, very aggressively for mileage. Very, very annoying as it does that all the neighborhood/slow speed city driving really stinks. Tranny is very confused. If I put it into tow/haul, it stays in gear much longer and there is no issue. Seems like it might be tuned for an engine with much more torque or a 3.73 or 4.10 rear end.

    2nd. When slightly rolling (1mph or less) and then trying to accelerate, there is a slight 1/2 second delay, then the power kicks in and everyone's head jerks back. I have to be very, very, very gently on the pedal and feather it through this until the engine/power engages. This seems like it might be a throttle issue or something to do with the fuel delivery. Does this truck have a throttle cable, or is it electronic?

    3rd. Problem. Towing. Under hard acceleration (not w.o.t., but well past 3/4 throttle) and towing 2k--4K trailer, there are multiple times where the tranny "jumps" or slips in between 2nd-3, 3-4, and 4-5. Engine revs slightly and it jerks into gear. Again...seems confused.

    I have had this truck to the dealer for warranty work on tranny. There are no codes. They could find nothing. I explained everything to my dealer as I have in this post. It is due to go in again. I checked tsb's and couldn't find any that seemed to be related to the issues I am having. HELP"


    This is not normal and after 2 more trips to the dealership they can't help me. They can feel the problem and have verified that there is a problem but the computer doesn't kick out any codes so no help for me. Problem is still there and if this is "normal" they GM had a lot of work to do. They gave me a 2012 to drive as a loaner. Same engine 5.3l. Same 6 speed. Same 3.42 rear end. Totally different truck. No issue. Way way way better. To bad there aren't any updates for tuning my tranny. I want to get rid of this truck. Nicest truck I have ever owned. Really like it. Engine is fantastic. Interior is great. Tranny is horribly tuned. GM customer service pretty much said there is nothing they can do. Anyone have luck with an after market tunes? I like Banks. Anyone try their stuff with this combo (stinger system). Thank you very much.
  • chuck1chuck1 Posts: 1,405
    edited March 2012
    From another source- 2012 truck 5.3-6 speed-Some problems same as yours-

    Anyway, the latest on my tranny. 1st time they replace valve body. The 2nd time in they replaced the TCM per GM, but a higher up at GM told the service tech that it could likely return because it is a software issue and they are working on it. So far it has not returned.

    Maybe your dealer is not trying hard enough.

    The Diablo tune is very popular.
  • Dealer diagnosis - a failed selenoid, but one that is in a current allotment "series" known to have a small current failure rate for 2012's.

    Part recommended by technical assistance is on order by the dealer with an ETR of Thursday 3/22/12 ......

    The scary part is that it fails while underway and in use - could be on an interstate, steep uphill grade, etc with no warning signs .... I was lucky I think, that it failed how and when it did.
  • gmcustsvcsarahgmcustsvcsarah Posts: 1,964
    I'm glad to hear that they were able to diagnose your Sierra, bikerandy, but wanted to apologize that this situation came up so soon on your 2012 vehicle. Again, please continue to keep us up to speed on what's happening, and we're happy to assist if you should need us!

    GM Customer Service
  • I have a 2010 silverado 1500 same drivetrain etc. Same problems, which didn't begin untill 10,000 miles. My local Chevy dealer says they cannot find any problems, but REALLY?? This thing drives horrible now! I dread getting behind the wheel of the truck which I absolutely loved the first 10,000 miles. This is frustrating because there are so many posts claiming the same problems and once again, the dealerships play dumb! My 2004 Silverado gave me the same problems and I got rid of that with only 18000 miles on it. Guess it's my fault for trusting Chevy again...
  • gmcustsvcsarahgmcustsvcsarah Posts: 1,964
    Good morning frankie15oct,

    Reading your post, I can see how frustrating it would be to see similar issues arise in a newer vehicle that you had seen earlier. If we can look into this further with you, please get in touch via email ( with more information, including your name/Edmunds username, phone and address, the last 8 of your VIN and current mileage, and name of your involved dealership.

    GM Customer Service
  • I can sympathize with how you feel. I've had my 2009 LT 5.3L w/6 speed since I bought it in October 2009, and have put now almost 32,000 on it. Up until about 30,500-31,000 miles everything was fine and I've loved this truck. Best all around truck I've ever owned...until now.

    Over the past month, I had it into the Dealership twice, for a total of 9 days. It started with the transmission seeming to resist moving when first put into drive whenever I stopped. That was minor and I let it go for a month or so until it started doing other, more serious things.

    It began to stutter and shudder when shifted from reverse into drive. Sometimes it would not even go into drive until I shifted back and forth from drive to park to drive again. Sometimes it would then lurch into drive with a bang. When this continued to get worse and worse, I took it to the dealer. They had it for 5 days and told me that they had to replace a carrier bearing and almost all the planetary gears and returned it to me. The very next day, it started back doing these things again.

    In an attempt to keep from doing more major damage as described to me before, I took it back in. But only after having been belittled by the service coordinator with mentions that they cannot do anything unless it repeats while the mechanic is in the truck with me. After three calls like this whereupon it was intimated that the problem might not be real, I had enough and had to berate the service manager to get them to take the truck back in to look at again.

    They claim that they can find nothing wrong with it this time and, even though I was able to reproduce a minor version of the shuddering the day I came to pick it back up again, still want me to drive it while they "contact engineering and see if this has ever happened to any other trucks."

    This was two weeks ago and calls back to the dealership get me nothing except comments that it won't hurt the truck to drive it like this and if something serious happens they will tow me to the dealer for free!

    So the bottom line is that I am now being soured on the truck that I planned to drive for 200,000-300,000 miles and now have issues with every day, but must apparently wait until it breaks down before I will get any more attention to it.

    This is doubly sad for me as I have always had my best luck with GM vehicles in the past and currently have a 1997 Pontiac Bonneville my wife drives, that has 218,000 and runs like a top with nary a transmission problem its whole life.

    This is not how it should be.
  • gmcustsvcsarahgmcustsvcsarah Posts: 1,964

    If we can follow up on this with you and your dealership, please send more information (your name/Edmunds username, address and phone, last 8 of your VIN and current mileage, and the name of your involved dealership) to and we'd be happy to look into this further.

    GM Customer Service
  • OK, I will do that.

    Thank You,

  • galvezfjgalvezfj Posts: 12
    Hello Sarah, I recently purchased a new 2012 1500 siverado Lt 4x4. The truck does the same thing as some of these other owners. I got the truck with 2 miles on it and the first time it jerked out of 1st gear i thought i did something wrong. the dealer said not to worry about it. I have had the truck for 10 days now with less then 400 miles on it and this issue is still there. Reading about the transmission issues these trucks are having do I need to take the truck back to the dealer.
  • jjacksjjacks Posts: 16
    edited March 2012
    Okay, so I decided I'd buy another GMC for a tax write off in December. Looking for a deal, I found a 2011, but my dealer didn't want to go get it since it was about 130 miles out. So I made a deal over the phone and went and got it, whilst trading in my 2008 that had the preverbial propeller shaft slip yoke clunk. That clunk, at least I knew what it was. SO, running a bit late, hustled out the door, cranked up, hit the highway.....hmmm...thinks to self....this thing must have some flat spots on the tires from sitting a long time. Dealer called and I wasn't 10 miles down the road and they forgot some paperwork, had to turn back, documented the vibration. Fast all the way back, still vibrating! Finally take into local dealer at 2500 miles. First chance I had, and this is the list I took them: (yes, i printed out a list)

    1. Constant vibration. Gets worse with heat. Had vibration since drove off the lot.
    2. Excessive ring/pinion lash. Rear-end whines on deceleration. Needs ring and pinion.
    3. Poor throttle response. Especially at low speeds under 10 mph. Likely related to excessive drive train slack. Check throttle position sensor.
    4. Torque converter feels like it stays locked up to long and at very slow speeds on deceleration, the transmission downshifts like it is being downshifted manually. Shift points do not match appropriate speeds to make the proper shift.
    5. Upon cranking, engine revs excessively to around 1,800-2,000 rpm. To high.
    6. Whenever you first crank it up, and put it in a forward gear and reach about 5 mph, there is some kind of movement in the pedals/column. It’s like the adjustable pedal motor gets a touch of voltage for a split second. Irritating as hell.
    7. Poor engine oil pressure. I assume this is for gas mileage purposes. It’s not helping.

    The drive-train slack is severely excessive for any kind of new vehicle. Full disclosure, I am knowledgeable with high and low performance engines, and have modified, built, and rebuilt gas and diesel engines. I have also been in my fair share of transmissions. And lastly, I’ve been in several GM rear ends, Ford third members, and heavy equipment planetaries and third members. Set up lash, etc.
    In summary, and as my service records show, I don’t bring anything in like ‘wind noise’ or anything like that. When I bring something in, it has a legitimate problem. This truck has problems.

    One thing you will notice is that I didn't bring up the AFM issue. I'd be happy if I could get the vibration at 20-30 fixed, as it is the same vibration at 55-75. AFM just makes it a bit worse. GM, in their infinite wisdom, came up with the AFM for better mileage. One thing they can never do is "make it seamless". They can make 'cushier' cab mounts and such to dampen the imbalance, but it is physically impossible to rebalance an out of balance engine without turning the other 4 cylinders back on. You will feel it more with lower ratio rears, like 3.73-4.10 -vs- 3.42 -3.08 because of the 'dampening effect' of the higher ratios. What GM needs to do if they want the AFM concept is to drop ONE cylinder and rotate across the firing order to lessen the imbalance. That would help. Now, on to the 6 speed tranny. No doubt a mileage idea also. You can thank your government and the 15% enthanol mandate for the reduction in mileage that GM would like to compensate back with the pathetic software programming for this transmission. In theory, it is programmed to achieve the federal mandates. In reality, the thing sucks. I was told by the mechanic at my local dealer who was riding along proclaiming my tires were bad that the transmission will only 'live' this way. Uh huh, a fool would think that. It won't live as long the way they are set up.

    SO, back to ol shakey. Been to dealer 8 times I think. 2 service tickets. 2 new tires. Road force completed. Hey, guess what, I said it wasn't the tires....AND IT'S NOT. Okay, since I am a 'mechanic', but it is not my paycheck trade, I said look at the differential. I mean, the damn thing is whining...especially on a slight decline coast 50-40 mph. When something's talking, maybe you should listen. SO, here's the joke of the day. My local dealer mechanic said he checked the ring/pinion backlash. I said "what was it?",,answer .0045. That would be fine and dandy, but I have yet to see a contraption that allows this measurement without the rear cover being taken off, and it wasn't. He did the ol 'feel job' on the yoke, and got .0045. HAHA.

    But here's the kicker. The service manager with the mechanic standing there said, and I quote "GM will not let us tear into anything until it has 5,000 miles on it". Now I have 5,200 miles of vibration behind me and we're about to either get past the bs or get with the certified mail. I could fix the thing myself, and I may have to, but if it comes to that, somebody at GM will get the problem parts sent to them, possibly along with something my great dane leaves behind in the yard.

    What I suspect it is, is a combination of excessive ring/pinion lash combined with a mis-machined carrier that is allowing the spider gears to 'climb' the axle gears. I don't dare take the cover off yet, or they'll say 'oops, out of warranty bud'.

    If anybody has a clue was to what causes #6 above, please reply. Of course they didn't do anything.

    Ok chuck, what say you?
  • gmcustsvcsarahgmcustsvcsarah Posts: 1,964
    Good morning galvezfj,

    Does your Silverado have a 6-speed transmission?

    GM Customer Service
  • gmcustsvcsarahgmcustsvcsarah Posts: 1,964

    I understand that you have quite a bit of mechanical expertise and are very comfortable with working with vehicles. I see that the main unresolved issue that you've been in repeatedly for and are not satisfied that your dealership did their best to diagnose is the vibration that you've been experiencing since purchasing the vehicle. If you would like to set up a Service Request with my department to have this documented further, as well as followed up on to the best of our abilities, please send us an email at (include your name/Edmunds username, phone and address, the last 8 of your VIN and current mileage, and the name of your involved dealership).

    All the best,
    GM Customer Service
  • chuck1919chuck1919 Posts: 176
    #4,5.6.and 7 listed in the points above are either your opinion or the way the truck is programmed per your point about EPA mandates and gas mpg.

    In my view you probably shouldn't bought the vehicle.

    Other than that, I sincerely hope you get the vehicle fixed where you can live with it.
  • galvezfjgalvezfj Posts: 12
    Yes it is a 5.3 lt. 6 speed automatic transmission. Z71 4x4.
  • gmcustsvcsarahgmcustsvcsarah Posts: 1,964
    Hello again galvezfj,

    The 6 speed transmission uses adaptive shift controls. Adaptive shift controls continually compare key shift parameters to pre-programmed ideal shifts stored in the transmissions computer. The transmission constantly makes adjustments to improve vehicle performance according to how the vehicle is being used, such as with a heavy load or when temperature changes.

    During this adaptive shift control process, shifting might feel different as the transmission determines the best settings. When temperatures are very cold, the Allison Transmission and Hydra-Matic 6-Speed transmission's gear shifting could be delayed providing more stable shifts until the engine warms up. Shifts could be more noticeable with a cold transmission. This difference in shifting is normal.

    The idea behind the design of the adaptive shift control process was to maximize fuel economy. You can certainly have your vehicle checked into by your dealership if you like, and please do keep us posted! I had just wanted to provide this information for you to know what may be going on if your dealership says that the vehicle is operating normally.

    GM Customer Service
  • galvezfjgalvezfj Posts: 12
    edited March 2012
    Thank you for this information Sarah,

    This is my first chevy all my other vehicles are toyotas. 2 tacomas and a sequoia. I really like this truck since it is fully loaded. I will take it in to make sure everything is functioning normal. Its just when you take off from a complete stop the truck shift hard and jerks your head back pretty hard. never had anything like this happen in any other vehicle i own. thank you
  • jjacksjjacks Posts: 16
    Hey chuck, your view of me not buying the 'problem' may be right. Problem is, I've always bought chevy or gmc, not one ford, dodge, nissan, nor toyota.

    4,5,6,7 are facts, bud. I'm a mechanic. #6 is something weird,,,gonna take a bit to nail it down, but it's inexcusable nontheless. #4 = when you're idling around the neighborhood about 10 mph and you slow to turn in your driveway and it feels like you just got rear-ended,,,,that ain't adaptive shifting. #5 = is going to cause premature crank damage, possibly. Just what is to high, chuck, a 3,000 rpm start, aw hell, how about 5,000? It has a throttle body, tps, drive-by- wire problem. When you have to wait for it to come back down so you can put it in gear, it's to damn high, got it? It's not constant either, just random. #7 20 psi may be enough now, but what you gonna have at 100,000 miles?

    I bought a '87 with tbi that had a burnt valve and almost 300,000 miles for a few hundred bucks. I pulled one head, lapped in one valve, put it back together and put another 200,000 miles on it. It got better mileage and ran smoother, cranked better, than this 2011 'gem'.
Sign In or Register to comment.