Jump to content

Recommended Posts

Posted (edited)

I get a flare shift since 1k miles every cold start. 4k miles now. Hasn't gotten worse. Should I take it in?

Edited by m3n00b
Posted

I get a flare shift since 1k miles every cold start. 4k miles now. Hasn't gotten worse. Should I take it in?

My flare would be when the truck was warm and I shut it down for a short time, as if I was getting gas at a gas station. Then the first 2nd/3rd shift out of the box would flare, normally only the first time it would go thru the shifts but it had flare twice in a row once for sure, maybe twice.

I seen it pop my RPM up almost 1,000 once as I normally don't watching my tach.

Best of luck

Posted

I may have over reacted, the vibration was from the tires, they put two new goodyears on the front now shes smooth as silk.

 

Sent from my SM-G920V using Tapatalk

  • 6 months later...
Posted

Following this Thread as my truck is suffering from the same symptoms. Hard shift mostly on 1-2 shifts and on cold starts mostly taking off but sometimes coming to a stop, under hard accelerations it shudders and stutters before taking off, again on cold starts pulling off my driveway I press the accelerator and nothing happens.

  • 1 month later...
Posted

I may have over reacted, the vibration was from the tires, they put two new goodyears on the front now shes smooth as silk.

 

Sent from my SM-G920V using Tapatalk

 

I was going to say only shuddering is usually the TC but vibrations are 95% tires or rims with this new platform. The hard shifts can be just an update on the TCM which they did for me when the did my stator shaft repair recently. Big difference, acceptable now but not great. So just ask about an update or resetting the relearn.

  • Like 1
  • 3 months later...
Posted

I have the 5.3 engine with the tow package and 8speed tranny with 15000 miles on it. My issue is hard clunking when put into gear first and reverse when truck is in park. It doesn't happen all the time. Other than that no problems. I haven't talk to servicedept. yet ,but planning on it. Does this fall under the recall?

  • Sad 1
  • 11 months later...
Posted

I just had mine in because of shuddering in (pretty sure the transmission), giving it gas to speed up, without it shifting gears causes shuddering.  And I get the hard shifts.  And occasionally it feels like something int he trans/TC is engages when I start it, it lunges for a split second & then is fine.  Took it in & they flushed it & changed the torque converter.  Got it back yesterday, no difference.  :-(

  • Sad 1
Posted (edited)

Every GM vehicle I've owned w/ a V8 & THEIR tranny has exhibited the "slam" when first put into gear always worse when cold. GTO w/ 4 speed, Silverado w/ 4 speed, G8 GT w/ 6 speed, & 2x2014 trucks w/ 6 speed, & now my 2018 w/ 8 speed.....is it "normal"? I dunno - its normal for GM that's for sure. My belief is theres simply more volume in the casing of their trannies than is typical for other makes, they use a fluid that expands quite a bit as everything warms up - all the vehicles mentioned above are also known to run hotter than most other makes as well & that IS NORMAL - but I think the compensation somewhere in GM's recipe for mating a tranny to these applications results in a situation where all the clutch packs shift ring seals & the entire tranny assembly in general becomes "starved dry" of fluid as it cools after 6-8+ hrs of sitting & when you first start it up & put it in "D" it results in a harsh/abrupt slam until all the fluid is warmed up & recirculated the harsh shifts & flares are more obvious & present.

 

Problem is the tuning from the factory is a mess as well in efforts to perform well in "instrumented testing" to meet CAFE regs (thanks again Barry) - I have learned firsthand how much a custom tune can help - in fact it essentially MASKED the mechanical flaws in the 6L80E in my G8 GT above & beyond the factory programming "flaws" - I forget exactly what it was mechanically something about the 2-3 & 1-2 ring seals installed backwards or something - but came down to fluid not flowing properly in the transmission again essentially. Pulled timing, weak ass shift torque, torque mgmt dialed in all over the map, constantly hunting for highest gear possible, etc etc etc

 

This isn't new for GM - its old hat, but keep adding gears & their shitty factory settings become more annoying & noticeable. That's my take anyhow.

 

That being said - I now have the joy of experiencing the latest & greatest mass problem w/ these shitboxes - the "phantom rumble strip" intermittent vibration that comes under light throttle when just cruising/maintaining speed & attempting to drive "smoothly" instead I'm rewarded w/ a pulsing vibration through the steering wheel that seems to be worst when going up a slight incline, happens regardless of speed or V8 vs V4, but seems to be worse as the truck warms up & seems to be focused in the 1200-1800 rpm range.

 

LOVE IT! Like ghetto lane departure warning! I think its the TC or tranny shitting the bed, we'll see....and for the longest time I seriously thought it was just the road.

Junk. Anyone who "congratulates" some poor sap who just bought a new one should be ashamed of themselves!!!!!! RUN AWAY is what you should be telling people....

Edited by crushNchowda
Posted (edited)
10 hours ago, crushNchowda said:

That being said - I now have the joy of experiencing the latest & greatest mass problem w/ these shitboxes - the "phantom rumble strip" intermittent vibration that comes under light throttle when just cruising/maintaining speed & attempting to drive "smoothly" instead I'm rewarded w/ a pulsing vibration through the steering wheel that seems to be worst when going up a slight incline, happens regardless of speed or V8 vs V4, but seems to be worse as the truck warms up & seems to be focused in the 1200-1800 rpm range.

I have had A 2017 8 speed max tow and now a 2018 8 speed max tow same truck. Long story sold the 17 to family member. Replaced 2 converters and several flushes. They both exhibited the exact same vibration as you described. Not bad unless your towing something. Then it really is severe. It is from the torque converter pulsing is how I would describe it. Get used to it as it won’t go away   I noticed the 2019+ 8 speed is using a different converter.   Hope they rectify as it is a great truck otherwise. On a positive note - the erratic trans shifting clunks are gone. Much better shifts but time will tell. 

Edited by Bigmac
  • Sad 1
  • 1 month later...
Posted

I have a 2017 Canyon 4x4 SLE started Shuttering and shaking at highway speeds at about 12000 mi continually getting worse! The worst shudder shaking is at about 55 steady speed with slight off and on exelaration to hold the speed in cruise or whatever. However it will do it at nearly any speed at times. Yes it helps when cruising at hwy speeds to downshift to 7th but that’s not what you should have to do! Besides it will do it in 7th too when it pulls just right up a grade.I thought the tires were out of balance and took it back to the dealer which re-balanced all of them and didn’t help at all. So I have another appointment next week. Going to give them a ride and shake their teeth out to show them what it is doing! The truck only has a little over 14000 mi. On it so this is completely unacceptable! And getting worse! I noticed the transmission temp. Will get up to around 150º at times and the hotter it gets the worse it gets; probably already damaged the internal parts... After all I have read on this forum and others about this I don’t think I’m going to go along with all the “we’re going to fix it crap” and tell them either buy it back or give me another “new” different kind of truck and transmission maybe like the Duramax since it has the 6 speed in it. Any advice would be well taken on this issue. THANKS

Posted

I have a 2017 Canyon 4x4 SLE started Shuttering and shaking at highway speeds at about 12000 mi continually getting worse! The worst shudder shaking is at about 55 steady speed with slight off and on exelaration to hold the speed in cruise or whatever. However it will do it at nearly any speed at times. Yes it helps when cruising at hwy speeds to downshift to 7th but that’s not what you should have to do! Besides it will do it in 7th too when it pulls just right up a grade.I thought the tires were out of balance and took it back to the dealer which re-balanced all of them and didn’t help at all. So I have another appointment next week. Going to give them a ride and shake their teeth out to show them what it is doing! The truck only has a little over 14000 mi. On it so this is completely unacceptable! And getting worse! I noticed the transmission temp. Will get up to around 150º at times and the hotter it gets the worse it gets; probably already damaged the internal parts... After all I have read on this forum and others about this I don’t think I’m going to go along with all the “we’re going to fix it crap” and tell them either buy it back or give me another “new” different kind of truck and transmission maybe like the Duramax since it has the 6 speed in it. Any advice would be well taken on this issue. THANKS

I had a similar issue. The dealer performed a trans flush and it resolved it.

Sent from my SM-T817V using Tapatalk

Posted

update: Took it to the dealer today and had the service manage ride with me to show him and have it documented that it will shake your teeth out while cursing. however when he got into the truck he said "I'll take a ride with you but I am well aware of this problem, I know what it is doing. I'm sure he does... he then told me they have to go through "the process" and do triple flush to see if that fixes it. said it probably would but if not they would put a new torque converter in it. I said if that will for sure fix it why not just go ahead and put it in there? GM says have to do the flush first... yeah$$$ I told him even if it fixed it how much damage has already been done to the longevity of the truck? Oh he said the transmission is fine... yeah sure. I had the lemon law book laying in the console so he could see it but said nothing. He knew what that meant... this whole thing makes me sick. I have always trusted GM and now they are trying to cover up an obvious recall issue. sickens me.

Posted
On 8/4/2016 at 10:54 PM, Boardmember said:

I have to wonder with all the searching, jerking, hesitating and jerking again what the hell its doing to my drivetrain life cycle.

X2 and that's why i lease.....pos will be in the used pool in 1.5yrs

  • Confused 1
  • Sad 1
Posted

Hate to admit - and I’ve not yet admitted on this forum - my Sierra is now a 2018 Honda Pilot Touring AWD.   I’m now a 140-mile/day commuter and when I bought my truck, I wasn’t.  

 

The calc was twofold.  Highway MPG has increased 40% and the depreciation schedule extended an unknown but certainly tremendous amount.  

 

My wife drives a 4Runner.   We still have a truck in the family.   

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Latest Articles

  • Posts

    • That makes sense, and I think you are describing the real product problem. Capturing data is the easy part. If the owner or technician has to manually dig through five minutes of millisecond-level logs, the product has already failed. The device would be at the ECM harness, not at the OBD port, so I agree that data retrieval and event marking need to be thought through carefully. The way I am thinking about the architecture is: The recorder itself should not depend on a phone, app, Bluetooth, Wi-Fi, or cloud connection to capture the event. It should always keep a local rolling buffer and lock the event locally. A button, phone app, or small cabin device would only act as an event marker. If the driver feels a stumble and presses the button 10–30 seconds later, the pre-buffer has to already contain the useful data. For data retrieval, the practical options would be a sealed service USB lead, Wi-Fi download, or a phone/cabin companion device. I would not expect the owner to remove the ECM-side module or work with raw files directly. The cloud or AI side would be for interpretation, not for capturing the event. The truck may have no connection when the issue happens, so the evidence has to be saved locally first. After that, cloud processing could help decode the data, compare it against baselines, and generate a readable report. For the first version, I would keep the automatic triggers conservative and objective: driver event marker bus-off error passive voltage drop / brownout device reset FIFO or queue overflow a normally periodic message disappearing side-to-side communication mismatch, if the topology supports that For “learning normal,” I agree with your point, but I would not want to overclaim it as automatic root-cause diagnosis at first. A realistic first step would be learned baseline comparison for that specific vehicle and operating condition. For example, a value would only be compared against similar conditions: RPM range load / MAP throttle position gear / vehicle speed coolant and oil temperature battery voltage AFM/DFM state, if decoded and validated Then the report could flag things like: this periodic message disappeared compared with its normal timing this value deviated from this vehicle’s normal range under similar conditions the same abnormal pattern repeated after the same type of event the anomaly occurred together with voltage, oil-pressure, misfire, or communication changes But I would still call that “abnormal pattern detected,” not “replace this part,” unless there is enough validated repair data behind it. So the intended product would not be “here is a huge log.” It would need to be an event package: what triggered the capture how much pre/post data was preserved what changed before and after the event whether the device itself reset, overflowed, or saw a bus error selected graphs around the event raw data only as supporting evidence From your perspective, what would make this kind of report useful instead of just another datalog? For example: What are the top 5 parameters or events you would want highlighted first? Would you trust a learned baseline for that specific vehicle, or would you prefer fixed thresholds? How much false-positive flagging would be acceptable before you stopped looking at the reports? What would a one-page report need to show for an independent shop to take it seriously? For misfire, AFM/DFM, oil pressure, or U-code complaints, what would you want the tool to flag automatically?
    • 2024 Silverado 2500 HD LTZ grille no camera Parts list   84603331 84913656 84913657 84913654 84913655 84911567 84911568 85646092 85646093 85797921 85797922   11570637  x10-15   grille/bumper bolts 11546500  x10      grille clips 11571006  x10      push/retainer clips 11546454  x6       nut retainers 11611609  x6       M5 bolts 11610700  x6       molding/trim retainers
    • And use RA's 5% discount code if you buy from them.  google for the code, one is always available.
    • Just don't turn the steering wheel as much?
    • Rockauto bud. I pass local stores for parts.   Findya something online. 
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...