Service Bulletin Bulletin No.: 16-NA-175 Date: February, 2019 TECHNICAL Subject: Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH (40 and 128 KM/H) at a Steady State Important: Follow the service procedures outlined in TSB 18-NA-355. Note: Required tool kit DT-52263 is shipping from Bosch.Service Procedure outlined in TSB 18-NA-355 for all models except the 2019 Chevrolet Silverado 1500 and GMC Sierra 1500 (New Body Style). For the 2019 Chevrolet Silverado 1500 and GMC Sierra 1500 (New Body Style), refer to bulletin 19-NA-121.Helpful websites. 18-NA-177 - RevBase - Chevrolet Bulletin RE: Procedure to confirm that shudder in Chevy Colorados and GMC Canyons is transmission related and if confirmed, directive to effect ...Repeat steps 2 and 3, clean the transmission oil pan and magnet....." (3rd time the pan gets dropped) Version 1 dtd Jan 17, 2019: View attachment TSB # 18-NA-355 Part 1.pdf View attachment TSB # 18-NA-355 Part 2.pdf (this is the one with Corvette specific procedure, pg 25) TSB #18 NA 355 wasShudder TSB 18-NA-355 has been updated 7/19 I just caught wind of a very important update to the transmission shudder TSB. Apparently, as of July 9th, the TSB has been revised to no longer require diagnostic procedures.TSB 18-NA-355. Note: Required tool kit DT-52263 is shipping from Bosch. All DT-52263 tool kits will ship from Bosch no later than February 14, 2019. If you encounter a vehicle with Torque Converter Clutch (TCC) Shudder prior to receiving tool kit DT-52263 please postpone the repair until you receive your tool kit. Performing repairs otherIt's also possible you will have some warranty left on the 2018. If it was a certified pre-owned, the powertrain warranty covers transmission/TC for 6 years 100k miles, otherwise I think the 2018 was 5 years 60k miles. I would personally get the '18 with zero hesitation. Just make sure you insist on them doing the flush per TSB 18-NA-355.Norcalace · #17 · May 6, 2022. MrYgrmstr said: My car is at the dealer for the next several days to fix the dreaded A8 shudder and a flaky infotainment screen. Man I hope it all gets resolved. As the title states, fingers crossed 🤞🏻. There is a Service Bulletin that covers your issue. It’s Bulletin # 18-NA-355.Service Bulletin Bulletin No.: 18-NA-355 Date: August, 2019 TECHNICAL Subject: Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH (40 and 128 KM/H) at Steady Speed Attention: This Bulletin only applies to vehicles sold in the U.S., Canada and Middle East Operations (MEO). Service Bulletin Bulletin No.: 18-NA-355 Date: August, 2019 TECHNICAL Subject: Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH (40 and 128 KM/H) at Steady Speed Attention: This Bulletin only applies to vehicles sold in the U.S., Canada and Middle East Operations (MEO). The latest revision of the shudder TSB (July 8 2019 : 18-NA-355 TSB) now states to go ahead and just do the flush if it has not yet been performed. This is good news, and what GM should have done from the beginning with this latest fluid if they were so confident in it.18-NA-355 TSB (Technical Service Bulletin) which I think is for the transmission fluid flush, the latest update addresses “torque converter clutch (TCC) shudder conditions on 8L45 and 8L90 ” eight-speed automatic transmissions, RPO codes M5N, M5T, M5U, and M5X. Affected vehicles include Chevrolet, GMC and Cadillac vehicles, as follows.Dec 13, 2018 · Hi John. My local GM dealer recently (1/24/19) diagnosed my 2016 Camaro SS with the same code as your Corvette (18-NA-355). I google searched it and found your post. They flushed and changed my transmission oil (13K miles) and the shudder has greatly improved. However, I am noticing some new hesitations as the transmission shifts in lower gears. Technical Service Bulletins. Technical Service Bulletins (TSBs) are recommended steps and procedures for repairing vehicles. A TSB is issued by an automaker when there is a growing trend with an unanticipated problems. The Silverado 2500 has been assigned 4536 TSBs, the most of any Chevrolet vehicle.Here is the tsb Bulletin #18-NA-355. Yes for both 8 speeds with shudder. The complains have declined much since this came out. There have been a few that it did not work for but they may have had ...Tl* the contact owns a 2016 chevrolet corvette. the contact stated that there was leakage of air on the front passenger side. after opening the convertible top, the front driver side had a leakage of air. the vehicle was taken to the dealer more than four times, but the vehicle could not be repaired. the manufacturer was notified several times ...TSB #18-039-20 Date Announced: APR 21, 2020 NHTSA ID: #10175733. Possible Driveability Issues due to the Winter-Blend Fuel into the Warmer Season Read More » TSB #18-089-19 Date Announced: NOV 01 ...Service Procedure outlined in TSB 18-NA-355 for all models except the 2019 Chevrolet Silverado 1500 and GMC Sierra 1500 (New Body Style). For the 2019 Chevrolet Silverado 1500 and GMC Sierra 1500 (New Body Style), refer to bulletin 19-NA-121.The issue about the TCC shudder that many of us have experienced, and apparently carried over to a variety of GM models with the same trans assembly, seems to pretty accurately described in TSB #18-NA-355 (22 pages). I got the TSB number, because the dealer printed it in my service invoice (N/C, since I am under the powertrain warranty).Service Bulletin Bulletin No.: 18-NA-355 Date: August, 2019 TECHNICAL Subject: Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH (40 and 128 KM/H) at Steady Speed Attention: This Bulletin only applies to vehicles sold in the U.S., Canada and Middle East Operations (MEO).Title: #18-NA-355 - Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH (40 and 128 KM/H) at Steady Speed - (Mar 30, 2020) Vehicle: 2017 Cadillac ATS The document preview is shown on the right. To view the entire document you need to have a subscription. Subscribe Sep 6, 2019 · My car was due for an oil change so I thought I would get the Thunk taken care of. I went in armed with the TSB #18-NA-355 dealing with the triple flush of fluids. However, the Corvette Tech specialist at the dealer said he would perform a complete diagnostic test before considering the TSB. Dec 13, 2018 · I just took my vehicle into the dealership and they performed the testing required per TSB 18-NA-355. They could not get the pco-scop to register a high enough vibration so they would not warranty the repair. I believe this was because the last TSB 16-na-175 fixed most of the vibration and the small vibrations would not register per 18-na-355. Aug 5, 2019 · Shudder TSB 18-NA-355 has been updated 7/19 I just caught wind of a very important update to the transmission shudder TSB. Apparently, as of July 9th, the TSB has been revised to no longer require diagnostic procedures. 18-NA-355 and 19-NA-121 have been updated effective July 9, 2019 to eliminate the diagnostics portion within the TSB's and the labor times have been updated to reflect the removal of the diagnostic procedures. Vehicles presented with suspected shudder within the published build dates should have the prescribed fluid exchange procedure performed.Sep 6, 2019 · My car was due for an oil change so I thought I would get the Thunk taken care of. I went in armed with the TSB #18-NA-355 dealing with the triple flush of fluids. However, the Corvette Tech specialist at the dealer said he would perform a complete diagnostic test before considering the TSB. Bulletin No.: 18-NA-355 August, 2019 Page 15 5181401 18.4. Shut the engine off once 16 quarts of fluid have been collected. 18.5. Properly dispose of the collected transmission fluid. 19. Raise the vehicle. 20. Remove the DT-52263-2 Cooler Line Plug from rear differential and install the transmission oil cooler line using a new retainer clip. 21.June 27, 2022 Sponsored by Lubegard General Motors has published multiple technical service bulletins pertaining to torque converter clutch shudder issues in their 8-speed transmissions. This problem currently affects 11 different models across 3 different OEM brands for the model years between 2015 and 2019.Jul 29, 2019 · Shudder TSB 18-NA-355 has been updated 7/19. 96258 Views 354 Replies 83 Participants Last post by DieselDrax , Sep 26, 2022 Jump to Latest. B. BevyofChevys Discussion starter · Jul 29, 2019. I just caught wind of a very important update to the transmission shudder TSB. Apparently, as of July 9th, the TSB has been revised to no longer require ... Noticed the shudder at just under 1200 miles, Dec '18, purchased car new 2/18. Had oil change and 18-na-355 done 2/19 at about 1400 miles. 5575 miles now, still no shudder. Shifts perfectly, quick, crisp.I've read 18-NA-177 and the older 16-NA-175 and now have found that an updated version of 16-NA-175 has this cryptic advice: Important: Do NOT replace the torque converter or transmission assembly for this condition. Engineer reviews have proven that replacing the torque converter does not provide a long-term solution to TCC shudder.I just caught wind of a very important update to the transmission shudder TSB. Apparently, as of July 9th, the TSB has been revised to no longer require diagnostic procedures. This is obviously big news for those of us who have had to jump through dealer hoops to get anything done.General Motors (GM) has been ordered to pay more than $100 million to classes of vehicle owners who argue the company sold vehicles with defective engines. A federal jury in California delivered the verdict against GM after less than one day of deliberation. It will benefit three classes of around 38,000 GM vehicle owners from California, North ...Shudder TSB 18-NA-355 has been updated 7/19. 96258 Views 354 Replies 83 Participants Last post by DieselDrax , Sep 26, 2022 Jump to Latest. B. BevyofChevys Discussion starter · Jul 29, 2019. I just caught wind of a very important update to the transmission shudder TSB. Apparently, as of July 9th, the TSB has been revised to no longer require ...I just took my vehicle into the dealership and they performed the testing required per TSB 18-NA-355. They could not get the pco-scop to register a high enough vibration so they would not warranty the repair. I believe this was because the last TSB 16-na-175 fixed most of the vibration and the small vibrations would not register per 18-na-355.Noticed the shudder at just under 1200 miles, Dec '18, purchased car new 2/18. Had oil change and 18-na-355 done 2/19 at about 1400 miles. 5575 miles now, still no shudder. Shifts perfectly, quick, crisp.Has the TSB 18-NA-355 Transmission Fluid Exchange fix your transmission shutter issues. We've linked to so many versions of TSBs it's easy to be looking at one when you think it's the other. I believe the one dated August 2019 is the most recent, with the last revisions in July, unless someone has found one that's even more recent.Mexico and Export Regions should follow Bulletin 19-NA-018. Note: This procedure should only be completed once per vehicle. Any vehicle that returns with suspect shudder should be diagnosed utilizing published diagnostics, GDS, PICO Scope or other diagnostic tools. Sometimes shudder is not caused by the torque converter clutch (TCC).Hi John. My local GM dealer recently (1/24/19) diagnosed my 2016 Camaro SS with the same code as your Corvette (18-NA-355). I google searched it and found your post. They flushed and changed my transmission oil (13K miles) and the shudder has greatly improved. However, I am noticing some new hesitations as the transmission shifts in lower gears.TSB 18-NA-355 is the one you want, but it also states to not replace the torque converter. With that said I was able to get mine replaced with the fluid/flush. It's likely dealer dependant. In my case the dealer saw the metal shavings in the fluid from the torque converter clutches, so they told GM, and they said to go ahead and replace itC7 General Discussion - LATEST TSB 18-NA-355 for AUTO TRANS SHUDDER - I found and attached the latest TSB 18-NA-355 regarding automatic transmission shudder. It was on the NHTSA website. The latest update is July 29, 2019. I also found another bulletin that applies, see attached TSB 19-NA-142Shudder TSB 18-NA-355 has been updated 7/19 I just caught wind of a very important update to the transmission shudder TSB. Apparently, as of July 9th, the TSB has been revised to no longer require diagnostic procedures.Service Bulletin Bulletin No.: 16-NA-175 Date: February, 2019 TECHNICAL Subject: Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH (40 and 128 KM/H) at a Steady State Important: Follow the service procedures outlined in TSB 18-NA-355. Note: Required tool kit DT-52263 is shipping from Bosch.Mexico and Export Regions should follow Bulletin 19-NA-018. Note: This procedure should only be completed once per vehicle. Any vehicle that returns with suspect shudder should be diagnosed utilizing published diagnostics, GDS, PICO Scope or other diagnostic tools. Sometimes shudder is not caused by the torque converter clutch (TCC).TSB 18-NA-355. Note: Required tool kit DT-52263 is shipping from Bosch. All DT-52263 tool kits will ship from Bosch no later than February 14, 2019. If you encounter a vehicle with Torque Converter Clutch (TCC) Shudder prior to receiving tool kit DT-52263 please postpone the repair until you receive your tool kit. Performing repairs otherApr 13, 2020 · Has the TSB 18-NA-355 Transmission Fluid Exchange fix your transmission shutter issues. Got the transmission service done last fall by the dealership at approx 71,000 km's. Now, about 7000 km's (approx 4500 miles) later, my 2017 Colorado still shifts very smooth. The big test will be towing, assuming it's even worth getting the trailer out of ... Apr 27, 2021 · C7 General Discussion - 18-NA-355 Shudder - Does Service Bulletin 18-NA-355 cover all 2017 model year Corvettes built before 2/1/19? Or does it only cover certain VIN’s? (M5U trans) Both my dealer and the Chevy customer assistance phone line say my vehicle is not covered because of my VIN. Bulletin No.: 18-NA-161 October, 2019 Page 3 Correction 1 Important: The following steps must be completed in order. Grasping or attempting to rotate cables could affect readings and should be doneafter performing the voltage drop measurement. Note: When checking voltage drop, the voltage drop should be performed with the fuelThe Technical Service Bulletin (TSB) #17-01-046 for this recall was published on June 3, 2017.2 Refer to . Hyundaitechinfo.com for the latest TSB.You are correct in generally the blue label isn't used on the 6-speed transmissions. 18-NA-355 applies specifically to the RWD 8-speed transmission, I had it performed on my Colorado. I have not seen any suggestion the blue label fluid would be detrimental to the 6 speed, but I don't think it's the answer.General Motors (GM) has been ordered to pay more than $100 million to classes of vehicle owners who argue the company sold vehicles with defective engines. A federal jury in California delivered the verdict against GM after less than one day of deliberation. It will benefit three classes of around 38,000 GM vehicle owners from California, North ...I just caught wind of a very important update to the transmission shudder TSB. Apparently, as of July 9th, the TSB has been revised to no longer require diagnostic procedures. This is obviously big news for those of us who have had to jump through dealer hoops to get anything done.Technical Bulletin - #18-NA-355 - Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH (40 and 128 KM/H) at Steady Speed - (Mar 30, 2020) - For 2017 Cadillac CT6. This bulletin is found in the CT6 Service Manual (Europe, Korea, N America, Other IO). For further information and the fluid exchange procedure, refer to GM corporate Technical Service Bulletin (TSB) 18-NA-355, available in Service Information. The Kit includes: • DT-52263-1 Block Assembly (with 10 foot long fluid drain hose and spring clamp) Jan 17, 2019 · 18-NA-355 18-NA-355 Shake And/Or Shudder During Light Throttle Acceleration Between 25 And 80 Mph (40 And 128 Km/H) At Steady Speed 1/17/2019 ATS Luxury ATS Premium Luxury ATS Premium Performance ATS-V CT6 Luxury CT6 Platinum CT6 Plug-In CT6 Premium Luxury CTS Luxury CTS Premium Luxury CTS Vsport CTS Vsport Premium CTS Vsport Premium Luxury CTS-V Evidently that one and 18-NA-355 have just been updated with the new information and keep their #s. 2017 GMC Canyon Denali V6 CCSB 4X4 [/QUOTE The TBS # on the work order for my 2019 Colorado was 18-NA-355. 20 qts triple flush 7/29/2019Service Procedure outlined in TSB 18-NA-355 for all models except the 2019 Chevrolet Silverado 1500 and GMC Sierra 1500 (New Body Style). For the 2019 Chevrolet Silverado 1500 and GMC Sierra 1500 (New Body Style), refer to bulletin 19-NA-121. Started experiencing the Transmission Shudder. GM refers to it as SERVICE BULLETIN 18-NA-355. Chevrolet Colorado 2017-2019. Condition: may be described as driving over low rumble strips or Highway with rough expansion joints. Cause: may be due to Torque Converter Clutch Shudder. Correction: Should have the appropriate fluid exchange procedure ...Jul 29, 2019 · Shudder TSB 18-NA-355 has been updated 7/19. I just caught wind of a very important update to the transmission shudder TSB. Apparently, as of July 9th, the TSB has been revised to no longer require diagnostic procedures. This is obviously big news for those of us who have had to jump through dealer hoops to get anything done. CAUSE Road test has shudder when the torque converter is applied. Command TCC on and shudder goes away. Checked fluid level and found condition is full and in good condition. Checked bulletins found #18-NA-355 said to flush and drain fluids in the transmission. CORRECTION Flush and drain fluids for transmission shake/shudder repair.Repeat steps 2 and 3, clean the transmission oil pan and magnet....." (3rd time the pan gets dropped) Version 1 dtd Jan 17, 2019: View attachment TSB # 18-NA-355 Part 1.pdf View attachment TSB # 18-NA-355 Part 2.pdf (this is the one with Corvette specific procedure, pg 25) TSB #18 NA 355 wasIn fact, 16-NA-175 refers readers to 18-NA-355 for service instructions. 18-NA-355 lists the PN for Mobil 1 Synthetic LV ATF HP as 19417577 for quart containers and 19417904 for 55-gal. drums but, as you stated above, both numbers are incorrect. The correct PN for the quart containers is 19353429.CAUSE Road test has shudder when the torque converter is applied. Command TCC on and shudder goes away. Checked fluid level and found condition is full and in good condition. Checked bulletins found #18-NA-355 said to flush and drain fluids in the transmission. CORRECTION Flush and drain fluids for transmission shake/shudder repair.Apr 13, 2020 · Has the TSB 18-NA-355 Transmission Fluid Exchange fix your transmission shutter issues. We've linked to so many versions of TSBs it's easy to be looking at one when you think it's the other. I believe the one dated August 2019 is the most recent, with the last revisions in July, unless someone has found one that's even more recent. Dec 13, 2018 · Hi John. My local GM dealer recently (1/24/19) diagnosed my 2016 Camaro SS with the same code as your Corvette (18-NA-355). I google searched it and found your post. They flushed and changed my transmission oil (13K miles) and the shudder has greatly improved. However, I am noticing some new hesitations as the transmission shifts in lower gears. Shudder TSB 18-NA-355 has been updated 7/19. 96258 Views 354 Replies 83 Participants Last post by DieselDrax , Sep 26, 2022 Jump to Latest. B. BevyofChevys Discussion starter · Jul 29, 2019. I just caught wind of a very important update to the transmission shudder TSB. Apparently, as of July 9th, the TSB has been revised to no longer require ...Aug 5, 2019 · Shudder TSB 18-NA-355 has been updated 7/19 I just caught wind of a very important update to the transmission shudder TSB. Apparently, as of July 9th, the TSB has been revised to no longer require diagnostic procedures. Jul 29, 2019 · Shudder TSB 18-NA-355 has been updated 7/19. 96258 Views 354 Replies 83 Participants Last post by DieselDrax , Sep 26, 2022 Jump to Latest. B. BevyofChevys Discussion starter · Jul 29, 2019. I just caught wind of a very important update to the transmission shudder TSB. Apparently, as of July 9th, the TSB has been revised to no longer require ... Service Bulletin Bulletin No.: 18-NA-355 Date: August, 2019 TECHNICAL Subject: Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH (40 and 128 KM/H) at Steady Speed Attention: This Bulletin only applies to vehicles sold in the U.S., Canada and Middle East Operations (MEO). Shudder TSB 18-NA-355 has been updated 7/19. I just caught wind of a very important update to the transmission shudder TSB. Apparently, as of July 9th, the TSB has been revised to no longer require diagnostic procedures. This is obviously big news for those of us who have had to jump through dealer hoops to get anything done.The auto manufacturers had no legal obligation to repair the cars. Technical Service Bulletins are issued by manufacturers when there is a problem found in a number of cars which does not have an ...Took to Chevy dealership in Dec. of 2019 (@30,000 mi.) to have TSB 18-NA-355 performed. The. Mobil 1 Synthetic LV ATF HP transmission fluid swap was successful until last week when I hit around 52,000 mi. and the same problems began to emerge.. Just took the truck back in for service today.18-NA-355 and 19-NA-121 have been updated effective July 9, 2019 to eliminate the diagnostics portion within the TSB's and the labor times have been updated to reflect the removal of the diagnostic procedures. Vehicles presented with suspected shudder within the published build dates should have the prescribed fluid exchange procedure performed.Service Bulletin Bulletin No.: 18-NA-355 Date: May, 2019 TECHNICAL Subject: Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH (40 and 128 KM/H) at Steady Speed Attention: This Bulletin only applies to vehicles sold in the U.S., Canada and Middle East Operations (MEO). Chevrolet TSB 18-NA-355 Make: Chevrolet Number: 18-NA-355 Title: Shake And/Or Shudder During Light Throttle Acceleration Between 25 And 80 Mph (40 And 128 Km/H) At Steady Speed Date: 1/17/2019 Models: 2017-2019 Camaro LS; 2016-2019 Camaro LT; 2016-2019 Camaro SS; 2017-2019 Camaro ZL1; 2017-2019 Colorado; 2017-2019 Colorado LT; 2017-2019 ...The issue about the TCC shudder that many of us have experienced, and apparently carried over to a variety of GM models with the same trans assembly, seems to pretty accurately described in TSB #18-NA-355 (22 pages). I got the TSB number, because the dealer printed it in my service invoice (N/C, since I am under the powertrain warranty).According to TSB (Technical Service Bulletin) 18-NA-355, the latest update addresses “torque converter clutch (TCC) shudder conditions on 8L45 and 8L90” eight-speed automatic transmissions, RPO codes M5N, M5T, M5U, and M5X. Affected vehicles include Chevrolet, GMC and Cadillac vehicles, as follows.Service Bulletin Bulletin No.: 18-NA-355 Date: May, 2019 TECHNICAL Subject: Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH (40 and 128 KM/H) at Steady Speed Attention: This Bulletin only applies to vehicles sold in the U.S., Canada and Middle East Operations (MEO).
I've read 18-NA-177 and the older 16-NA-175 and now have found that an updated version of 16-NA-175 has this cryptic advice: Important: Do NOT replace the torque converter or transmission assembly for this condition. Engineer reviews have proven that replacing the torque converter does not provide a long-term solution to TCC shudder. . Upgrade
TSB 18-NA-355. Note: Required tool kit DT-52263 is shipping from Bosch. All DT-52263 tool kits will ship from Bosch no later than February 14, 2019. If you encounter a vehicle with Torque Converter Clutch (TCC) Shudder prior to receiving tool kit DT-52263 please postpone the repair until you receive your tool kit. Performing repairs other Technical Service Bulletins. Technical Service Bulletins (TSBs) are recommended steps and procedures for repairing vehicles. A TSB is issued by an automaker when there is a growing trend with an unanticipated problems. The Silverado 2500 has been assigned 4536 TSBs, the most of any Chevrolet vehicle. I just took my vehicle into the dealership and they performed the testing required per TSB 18-NA-355. They could not get the pco-scop to register a high enough vibration so they would not warranty the repair. I believe this was because the last TSB 16-na-175 fixed most of the vibration and the small vibrations would not register per 18-na-355.Aug 5, 2019 · Shudder TSB 18-NA-355 has been updated 7/19 I just caught wind of a very important update to the transmission shudder TSB. Apparently, as of July 9th, the TSB has been revised to no longer require diagnostic procedures. For example, the GM service bulletin 18-NA-355 for the 8-speed 8L90 transmission recommends flushing the transmission to fix 'Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH'. If you have the 6-speed transmission check if the TSB 21-NA-199 has been done to your truck, as it helps to keep the transmission cooler.Apr 21, 2023 · This problem currently affects 11 different models across 3 different OEM brands for the model years between 2015 and 2019. After implementing several fluid revisions, GM’s latest solution (TSB 18-NA-355) is lengthy, complicated and expensive. It Posts: 23. TSB 18-NA-355 - After effects. Just recently had the 18-NA-355 service bulletin for my 17 SS A8 and noticing the transmission is acting much better but slightly different? The shudder is gone completely which is awesome but i am noticing the RPMs are idling a bit higher around 1800-2000 rpm in 8th at 65-70 vs 1500ish prior to the TSB.Which revision of 18-NA-355 was followed and which fluid was used? It matters. Reply. steven says: May 5, 2020 at 6:42 am #16-NA-361 Document ID:4605342 The latest fluid was used. Reply.Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH (40 and 128 KM/H) at Steady Speed. Attention: This Bulletin only applies to vehicles sold in the U.S., Canada and Middle East Operations (MEO). Mexico and Export Regions should follow Bulletin 19-NA-018.For example, the GM service bulletin 18-NA-355 for the 8-speed 8L90 transmission recommends flushing the transmission to fix 'Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH'. If you have the 6-speed transmission check if the TSB 21-NA-199 has been done to your truck, as it helps to keep the transmission cooler.I've read 18-NA-177 and the older 16-NA-175 and now have found that an updated version of 16-NA-175 has this cryptic advice: Important: Do NOT replace the torque converter or transmission assembly for this condition. Engineer reviews have proven that replacing the torque converter does not provide a long-term solution to TCC shudder.After implementing several fluid revisions, GM’s latest solution (TSB 18-NA-355) is lengthy, complicated and expensive. It requires 20 quarts/19 liters of costly ATF (the average retail, online price for this fluid is $18.10 per quart ) be flushed through the system to replace as much fluid as possible, yet, it still has not corrected the ...Jan 17, 2023 · For example, the GM service bulletin 18-NA-355 for the 8-speed 8L90 transmission recommends flushing the transmission to fix 'Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH'. If you have the 6-speed transmission check if the TSB 21-NA-199 has been done to your truck, as it helps to keep the transmission cooler. .