Return of the Shudder 9

Bobschatter · December 24, 2022

So in Dec. 2018, with barely 20,000 miles on the truck, I got the dreaded (torque converter) shudder. I had the "3-flush" procedure with the Dex 6 . It did resolve the shudder at the time but annoyed that a few months later the TSB about a new Mobile 1 LV was not sent forwarded to me. Fast forward to Dec. 15th and, yep, full on return of the rumble strip shudder. Of course, I just saw the Service Bulletin 21-NA-199, dated Dec. 2021, that emphatically states the194 deg. thermal bypass valve should be replaced with a new 158 deg. version (Part #86774933). The bulletin states "Some customers may comment on one or more of the following conditions-blah, blah, blah...slip, vibration SHUDDER." Why would GM not inform Owners? Obviously they felt the transmission fluid was running too hot and contributing to mechanical failures. Since I live in South Florida I would have replaced it myself to maybe prevent the TC issue and save wear on my tranny. Well, I took it in to the dealer who said that since the 3-flush procedure did not resolve the issue that the TC has likely failed and needs to be replaced at a cost of $2,996 as the 5 year powertrain warranty expired 5/16/21. The truck only has 35,000 miles on the odometer. Comments? Suggestions? Have the system flushed again and see what gives? Contact GM Customer Service and see if they will fix it? A bit disappointing as I had also bought new a 2012 Silverado 1500 LT CC that I traded in for the current truck and I still own the 2003 Corvette Convertible that I bought new as well.

Snowcamo · December 24, 2022

Comment.

If you want to keep it take it elsewhere and have it rebuilt with the sonnax zip kit. You'll be in for the same amount. Waiste money at gm and just

Wait for it..

CamGTP · December 24, 2022

A transmission shop shouldn't charge you $3,000 to replace the torque converter, I'd go there. Labor rates at dealerships have reached insane levels recently. Around here is $160-200 an hour and the techs are only making $25-35hr, talk about raking in the money. Years ago I was making just over 20 an hr with commission when labor rates were like $120hr and we still made money for the business, how times have changed in the past 10 years. End rant lol

Narfengarbler · January 5, 2023

I'm sorry, I'm unclear as to whether or not you ended up getting flushed and replaced with the new Mobil fluid that was supposedly designed to fix the problem. Apparently the previous fluid was too hygroscopic (attract water) and pulled water from the air in humid climates. I live in Arkansas and it's very humid here as well during the warm months. My truck got the shudder not long after they came out with the new fluid. The dealer for it flushed and switched over, and I haven't had a problem with it since. Figured I'd at least throw that out there in case you haven't got the new fluid. Would likely be a heck of a lot cheaper and worth a try.

grandpapa20_ · January 6, 2023

On 12/23/2022 at 7:55 PM, Bobschatter said:

So in Dec. 2018, with barely 20,000 miles on the truck, I got the dreaded (torque converter) shudder. I had the "3-flush" procedure with the Dex 6 . It did resolve the shudder at the time but annoyed that a few months later the TSB about a new Mobile 1 LV was not sent forwarded to me. Fast forward to Dec. 15th and, yep, full on return of the rumble strip shudder. Of course, I just saw the Service Bulletin 21-NA-199, dated Dec. 2021, that emphatically states the194 deg. thermal bypass valve should be replaced with a new 158 deg. version (Part #86774933). The bulletin states "Some customers may comment on one or more of the following conditions-blah, blah, blah...slip, vibration SHUDDER." Why would GM not inform Owners? Obviously they felt the transmission fluid was running too hot and contributing to mechanical failures. Since I live in South Florida I would have replaced it myself to maybe prevent the TC issue and save wear on my tranny. Well, I took it in to the dealer who said that since the 3-flush procedure did not resolve the issue that the TC has likely failed and needs to be replaced at a cost of $2,996 as the 5 year powertrain warranty expired 5/16/21. The truck only has 35,000 miles on the odometer. Comments? Suggestions? Have the system flushed again and see what gives? Contact GM Customer Service and see if they will fix it? A bit disappointing as I had also bought new a 2012 Silverado 1500 LT CC that I traded in for the current truck and I still own the 2003 Corvette Convertible that I bought new as well.

Well I do know from my experience working at a Chevy dealership, when the shutter first starts they flush transmission system, if it occurs a few hundred miles after then torque converter was replaced. When I was there at the dealership, If the shutter came back after that then transmission had to be replaced. Best bet is since your truck is out of warranty, get a new transmission and make sure it comes with a new converter as well.