Fish Bite/Chuggle

[Iceman22]

Scuba,

Don’t mean to thread jack but just want to describe my issue and see if it’s the same thing you’re dealing with...

About 300 miles ago I️ started to get what appears to be a driveline shutter that’ll consistently show up between 40 to 54mph when the truck is going up a slight incline and I’m light on the throttle; maybe 20% input?

The truck will also sometimes do it from 60 to 75mph under the same circumstances: light throttle and slight uphill grade.

Truck will not do it going down hill, going up a steep hill, under heavy throttle input or off throttle.

Feeling can be described as someone who puts a manual transmission in too high of a gear for the speed at which they’re starting from. The feeling is a consistent “duh-duh-duh-duh” especially noticeable through the steering wheel? But it’ll go away the second you get heavy on the gas or get off it entirely?

Sucks because the truck just clicked 20,000 miles. Idk if it’s a good or a bad thing that it just manifested itself vs. it being like that from day 1.....





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[Scuba78]

11 minutes ago, Iceman22 said:

Yes. That is exactly what i was dealing with too.  Dealership agreed with me about the issue and we tried alot of things to get thru it. A lot of test drives and data-logging to get a GM engineer involved, only to hear it is normal and they wont do anything with it.  the Black Bear Tune resolved it for me as far as i can see today with one drive in. I am just surprised it is finally gone i guess! lol




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[Iceman22]

My truck is scheduled to have my complaint diagnosed on Thursday. The service manger stated that it sounded like I was describing a faulty TCC but didn’t want to be definitive over the phone and rightfully so...

 

I assume that Avenue was looked into at your end as well?

 

 

I’m just so completely conflicted about your answer. While I’m super disappointed to hear Chevy pretty much said “operating as designed” and wiped their hands clean of it; I’m elated to hear BBP was able to correct it since I just so happen to have this waiting for me....

 

I just bought it with the hopes of getting a little more performance out of my 6.2 to counteract the heavier wheels and tires I just put on. Didn’t realize it may be able to fix the driveline shutter. I’ll give Chevy a chance to fix it since it’s under warranty but it’s good to know I have the BB tune in my back pocket!

 

 

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[juscuzram]

My wife's Equinox does this now and then around 35 mph or so when accelerating. Haven't felt it from my Silverado yet, but I always wondered what caused it.

 

[roundhouse]

3 hours ago, Scuba78 said:

i have had every TSB and update available.  Noting from factory has helped, but i solved the issue myself, with help from Black Bear Performance!!! i sent them my read file and told them the issues im having, they sent me the tune last night ant this is the first day with the truck after 20k miles it didnt lug and chug at ALL!  I will be going to my dealer to show them the results to just shake it in the engineers face.  What good is a warranty if they wont do anything about it anyway!

Wonder why GM with thousands of engineers can't fix it and a small company can  fix it ???!

 

answer :. GM is full of mouth breathing morons from the CEO and top engineers down to the tards at the stealership 

 

I took this one in for its "free" oil changes and  even made an appointment 

only took em 3 1/2 hours to change the oil 

WITH an appointment 

 

if I took it in to get the chuggle fixed , they'd need what , six months ??

 

 

is there a way to get a tune that makes the Trans shift up like a normal Trans should instead of going to 6th gear at 33 mph while going uphill?

[Scuba78]

5 minutes ago, roundhouse said:

Wonder why GM with thousands of engineers can't fix it and a small company can  fix it ???!

 

answer :. GM is full of mouth breathing morons from the CEO and top engineers down to the tards at the stealership 

 

I took this one in for its "free" oil changes and  even made an appointment 

only took em 3 1/2 hours to change the oil 

WITH an appointment 

 

if I took it in to get the chuggle fixed , they'd need what , six months ??

 

 

is there a way to get a tune that makes the Trans shift up like a normal Trans should instead of going to 6th gear at 33 mph while going uphill?

Yes, i too had those issues but with Black Bear they changed the TCM as well and in my opinion it drives how i would drive a manual.  it holds the gear it needs instead of the one it should be in on the highway!

[swathdiver]

Is it possible that the fix involves changes that would make the trucks fail emissions or reduce their fuel economy?  This may explain why the engineers won't fix it.  

 

Did Justin say what changes were made to get it drive normal?

[roundhouse]

I'm sure it's done to improve the mpg by 0.00001 

 

indont nt give a flip of it uses another nickel a month in gas to shift like a normal vehicle should 

 

why people worry about mpg and don't consider depreciation is really strange 

 

I have never and will never buy a brand new vehicle 

I buy mine 5-7 years old at an auction 

last one was a 7 yr old 4wd EB expedition in excellent condition with every available option that cost $51k new and I was the top bidder at $6400 

 

so the person bought it new lost $43k 

. But they were probably constantly complaining about the 11.5 mpg in town 

 

and I wont be buying any more late model vehicles either 

they are intentional made to be so complicated that no one can work on them 

 

when my expy wears out , likely the vvt or transmission , my next vehicle will be the nicest 88-91 K-5 Blazer I can find 

.   I need reliable 4wd SUV or truck that can be maintained by an average mechanic 

 

I don't need the freaking space shuttle on wheels with 18 computers and 26 miles of wiring 

. 

[swathdiver]

On the one hand I'm with ya, I hate all this stuff and trying to fix it when it goes bad.  But I do like the heated seats and other luxury features.  I miss the low rpm high torque engines too.  A Tech2 is a MUST have when working on these newer trucks.  A '91 Suburban would be cool but I'm going to stick it out with my 2009 for a while.  I did enjoy buying one vehicle new with no miles but probably won't ever do it again.  Like you, I always wait until they are 4-8 years old or so.

[Ryan Wyatt]

On 11/8/2017 at 7:34 AM, roundhouse said:

I drive a 17 owned by the company I work for and have noticed the same thing 

 

it's very irritating 

no wonder GM had to get bailed out by the fedgov 

I have not taken it in for repairs because I know GM is too stupid to be able to fix it 

     I figured it was something to do with the CAFE ratings , it's really irritating that this stupid truck will up shift into 6th gear doing 35 mph uphill 

so that when go up the next slight hill in a residential neighborhood mashing the gas pedal does nothing to increase power until you totally floor it causing it to slam down into 3rd and take off like a rocket , there is no way to accelerate in between these two modes unless you drive it in the Manual  mode and shift it your self 

   Using the trailer tow mode helps but the "grade braking " slamming down gears every time you ease off the gas pedal is irritating too 

    Lexus had rev matching downshifts about ten years ago and GM can't do it ??

 

it's also hard to believe that they sell a vehicle without power mirrors 

and if you don't buy the option package with the  remote control to lock and unlock the doors GM has purposely written the software so it can never be added later 

 

 

The previous company i worked for had crewmax tundras and wow, that's the truck to have . Plenty of power and a very intuitive transmission , rides a hell of a lot better too 

 

GMs bailout had nothing to do with the quality of their trucks.

You can thank the governments hypocritical stance on "global warming" And forcing large industries to shell out billions of dollars conforming to their ever changing "green" policies while forcing them to spend even more on R&D to make their future products comply with the ever growing eco friendly set of laws all the while they have made very little change in the technology, consumption and/or conservation in our countries largest contributor of green house gases.... our military and military vehicles and aircraft.

 

The big bank bailout was not a bailout to stop certain companies from closing their doors.  These companies would still exist today if they had not received any money.  That bailout was set into motion to save only 1 "company" And that company was the US government and our governments stance as the world's economic super power.  

 

It would take a book to explain the complexities of that bailout but I just find it irritating that people still assume that large corporations that received money in that bailout were to keep them from closing their doors and that's just not the case.

[SGS_Z71]

I have a post going through the same crap you went through, and am considering trading in or tuning.  Can you report back if you are still happy with the tune?  I just spend 3 hours yesterday driving through the hills of Kentucky/Tennessee yesterday on I75, and it chuggled on every dang hill.  I wanted to push it off a cliff.  Would appreciate your feedback on the tune and any more information relative to such.

 

thanks!

[sdeeter19555]

In my honest opinion, it's the shift points of the trans...it tries to hold the trans locked in gear when it should either unlock the converter or drop a gear.

I complained about this in 2012, as my truck has did it since day one...I was told the TCM was reprogrammed for the 2011s and newer to hold gears as the complaint was the trans shifted too much. I think this forced gear holding is causing the engine to lug too much.

Steve
2012 2500hd 6.0l

[Crstfr]

mine does the same.. shudder between 50-60 on light acceleration, and also hard shifts up and down from 1-2, and 2-1.... 

 

going to try and make an appointment for it... hopefully they wont give me the run around.

[SGS_Z71]

So on mine today, if I brake torque it while driving down the road it will chuggle all the time.  This is the first time I’ve been able to recreate it like that.  Any thoughts?

[Jonger1150]

I'm joining this thread... same issue here.

 

I bet this issue affects 100% of all Silverado half tons with the same 6 speed trans.

 

Has anyone ever had this fixed with the firmware flash or should I just live with it until I'm ready to get the black bear tuner.

 

Also, I'm new to tuners. Is there a downloadable setting adjustment that can match the others who had success?

 

And... the downshift clunk. Will the black bear fix this as well?

 

Last, can I just revert this back or will my powertran warranty basically be gone?

 

I plan on keeping this truck long term, it fits all my needs and overall I like it... but these two issues do impact my opinion of the truck.

 

summary -- Want to get rid of chuggle and downshift clunk.

Edited March 3, 2018 by Jonger1150