16-NA-175 8 Speed Shudder UPDATE

[Black02Silverado]

36 minutes ago, AdioSS said:

Reading this thread gives me hope & pisses me off at the same time. My 18 Sierra developed the shudder early on. I took it to the dealer for the first oil change a couple hundred miles ago. They said I do have the shudder (duh), but they have several customers ahead of me “waiting on parts” & will contact me when they come in... 

 

It is just a thorough fluid flush, right? 

Yes, there is an updated fluid that came out this past January. 

[Boomer727]

Have contacted an outstanding repair shop in Cypress Texas called Skeeters.  They were not convinced it's a torque converter and sent me a copy of a service bulletin which suggests replacing the brake pedal position sensor which may actually be the part responsible.   It discusses that there is a very particular voltage range that must be maintain, if not it can interact both with the brakes and the torque converter to cause this shudder.  Also, I found that the shudder is dramatically lessened by disengaging the the TC system with the switch.   I am going to replace the BPPS to see if that further helps.  The BPPS is less than $30 and takes less than 5 minutes to replace. 

[nobaddays]

Just had mine done yesterday and I definitely noticed an improvement. The fix is new fluid and they flush it with 20+ quarts to get all the old fluid out. 

[dwchapmanjr]

29 minutes ago, nobaddays said:

Just had mine done yesterday and I definitely noticed an improvement. The fix is new fluid and they flush it with 20+ quarts to get all the old fluid out. 

I'm about 7 months out.  It had that "caddy" ride for about a month but back to factory normal now.  Sometimes clunky shifts, etc but what I would expect from a truck transmission so no complaints.

 

I noticed AFM stays engaged more even under slight pedal press so they modified the sensitivity on that with new programming so it has a slight vibration at even lower RPMs like 1100 if you have some slight acceleration which is what I think they were trying to avoid with the TCC pulsation to begin with.

[MD11G200]

On 8/24/2019 at 12:49 PM, Boomer727 said:

Have contacted an outstanding repair shop in Cypress Texas called Skeeters.  They were not convinced it's a torque converter and sent me a copy of a service bulletin which suggests replacing the brake pedal position sensor which may actually be the part responsible.   It discusses that there is a very particular voltage range that must be maintain, if not it can interact both with the brakes and the torque converter to cause this shudder.  Also, I found that the shudder is dramatically lessened by disengaging the the TC system with the switch.   I am going to replace the BPPS to see if that further helps.  The BPPS is less than $30 and takes less than 5 minutes to replace. 

did this fix your shudder problem? that seems a little far fetched for a cure

 

[dwchapmanjr]

2 hours ago, MD11G200 said:

did this fix your shudder problem? that seems a little far fetched for a cure

 

I'd be interested to know too.  I mean, each case/issue can be unique but there is definitely a TCC/fluid issue that's known.  My 2004 Canyon BPPS did go out a few times and was recalled 1-2 times.  While it was less sophisticated, it only resulted in the break lights not working and cruise control being disabled but I could see where a pulsating signal may cause some issues.

 

If this didn't fix the issue, since Boomer727 is in the metro area, I'd recommend Mack Haik Chevrolet.  They did my last fluid flush and that seems to have fixed it for now.  Its only been about 10 months though.  Not sure what the cost would be out of warranty though.  I still have about 9 months left on my powertrane warranty.

[Abiker21]

I had my fluid flush at the end of 2018 and it worked well, but this past week had my transmission temp sensor harness replaced for P0711 under the powertrain warranty(inside the transmission) . My point is I had a code but the light never came on. By the time it hard failed I probably would have been out of warranty and driven on an erratic transmission for months. They misdiagnosed the problem and I paid for a new TCM. After too many bad experiences with Chevy dealerships, I now only take my truck to GMC. Better customer support and they appropriately diagnosed and fixed my transmission under warranty. Keep an eye on your trans temp while warming up. It should only increase. Mine was jumping all over and occasionally dash out. 

[Bash74]

I had my fluid flush at the end of 2018 and it worked well, but this past week had my transmission temp sensor harness replaced for P0711 under the powertrain warranty(inside the transmission) . My point is I had a code but the light never came on. By the time it hard failed I probably would have been out of warranty and driven on an erratic transmission for months. They misdiagnosed the problem and I paid for a new TCM. After too many bad experiences with Chevy dealerships, I now only take my truck to GMC. Better customer support and they appropriately diagnosed and fixed my transmission under warranty. Keep an eye on your trans temp while warming up. It should only increase. Mine was jumping all over and occasionally dash out. 

This is why I scan my own truck every month. Having a good scanner is a tool I suggest everyone have.

Sent from my SM-G935V using Tapatalk

[davester]

Lots of codes can be generated without turning on the CEL.  It's defined to come on when an emissions-related problem has been detected, and flashes when an emissions problem is currently happening.

[booster]

On 10/18/2019 at 10:09 PM, Abiker21 said:

I had my fluid flush at the end of 2018 and it worked well, but this past week had my transmission temp sensor harness replaced for P0711 under the powertrain warranty(inside the transmission) . My point is I had a code but the light never came on. By the time it hard failed I probably would have been out of warranty and driven on an erratic transmission for months. They misdiagnosed the problem and I paid for a new TCM. After too many bad experiences with Chevy dealerships, I now only take my truck to GMC. Better customer support and they appropriately diagnosed and fixed my transmission under warranty. Keep an eye on your trans temp while warming up. It should only increase. Mine was jumping all over and occasionally dash out. 

I've had an opposite experience between Chevy and GMC dealers. Took my truck in a few years ago to have the transmission serviced at Nyle Maxwell GMC for the shudder issue. https://www.facebook.com/NyleMaxwellGMC/ They replaced the torque converter and trans filter and it appeared to be fixed. A year later the same issue is occurring and I called to make an appointment at the same dealer and they told me GM isn't going to replace any more torque converters so I'll just have to live with the issue. Fast forward a couple of years and I read about the 18-na-355 TSB and decide to take it to another dealer who determines that Maxwell damaged the replacement trans filter during installation. Maxwell's service manager's opinion was something should have happened while it was under warranty otherwise they couldn't care less. This would be the 2nd time I've had issues with Maxwell's service department and shoddy workmanship. The general manager indicated that they would be willing to correct the issue at no cost to me and basically strung me along for a week and then ultimately declined to cover their mistake. They authorized the other dealer to fix the issue and then declined to cover it thereby holding my vehicle under ransom until I had to pay for their mistake. Below is damage to the filter.

[Slvijoe]

1 hour ago, booster said:

I've had an opposite experience between Chevy and GMC dealers. Took my truck in a few years ago to have the transmission serviced at Nyle Maxwell GMC for the shudder issue. https://www.facebook.com/NyleMaxwellGMC/ They replaced the torque converter and trans filter and it appeared to be fixed. A year later the same issue is occurring and I called to make an appointment at the same dealer and they told me GM isn't going to replace any more torque converters so I'll just have to live with the issue. Fast forward a couple of years and I read about the 18-na-355 TSB and decide to take it to another dealer who determines that Maxwell damaged the replacement trans filter during installation. Maxwell's service manager's opinion was something should have happened while it was under warranty otherwise they couldn't care less. This would be the 2nd time I've had issues with Maxwell's service department and shoddy workmanship. The general manager indicated that they would be willing to correct the issue at no cost to me and basically strung me along for a week and then ultimately declined to cover their mistake. They authorized the other dealer to fix the issue and then declined to cover it thereby holding my vehicle under ransom until I had to pay for their mistake. Below is damage to the filter.

Dealerships are not your friend. 

They like to urinate on your shoes and tell you it’s raining. 

 

[High Country 6.2L/8]

On 11/9/2018 at 8:48 AM, newdude said:

 

Exhaust note change with tach flutter is typically AFM.  The rumble strip feeling is a common symptom of A8 converter shudder. 

Agreed that flutter is AFM. Delete like I did and have flush replaced with Amsoil ATF and a relearn no more issues and that's a year ago.

[MD11G200]

The flush done with the new fluid and it helped tremendously both the shudder my truck eventually developed as well as the horrible clunky downshifting. Hard downshifts not gone but much better.

Through consistently filling out the emails sent to me by GMC to rate the dealer( sent very delineated emails responses to surveys about how pissed off I was after 5 dealership visits and no fix) after work was performed I was contacted by a regional guy from GMC who offered me 3 options to try and help:

1. Have field engineer come out an drive my truck(since flush fixed MOST of the problem elected not to do this)

2. $4500 cash towards the purchase of any new GMC vehicle, I would have to negiote the price with the dealership, then they would apply the $4500 to the deal( don't really trust another new GMC vehicle, so didn't do this)

3. extend my transmission, transfer case and trans axle warranties and all related items another 5 years/75,000 miles from the trucks current milage. ended up with a warranty on those items good til 01/03/2025 or 118,335. Was best option for me since I drive my truck about 15-18K a year.

 

I would say to anyone having transmission problems be sure and always answer dealership surveys if you receive one. Only time will tell if my transmission starts all the bad clunky cramp and shudder again.

 

Hope this helps someone

 

[Martinez15]

I’m having the same issue has there been a fix yet? Shudder/hake

[dwchapmanjr]

On 10/18/2019 at 10:09 PM, Abiker21 said:

this past week had my transmission temp sensor harness replaced for P0711 under the powertrain warranty(inside the transmission) . My point is I had a code but the light never came on

Resurrecting the dead.  I had a P0711 earlier in the week with a P0700 (this caused the dash MIL).  Cleared it and only P0711 came back which doesn't cause the MIL.

Did they replace the temp sensor based on P0711 alone?  For P0700 and the dash check engine light to happen P0711 has to trigger two drive cycles.

What I did notice is my thermostat seems to be stuck open as transmission never gets up to temp like it used to.  Thermostat opens at about 192F I believe.

 

More related to this topic, I'm nearly 2 years out on my flush with the "new" fluid and no shudder but I do have rough shifts that I believe may be related to temperature or temp sensor.