[jcsuddre]

Is there a new tsb number for this flush ? I called my dealer and they tried to look up the 16na175 and it couldn’t be found . I see that it was eliminated when reading the update . My dealer told me they were not aware of the issue but then I described it to them and they scheduled me for an appointment to ride along so they can experience what I’m describing .

[crosive]

Originally Posted by Klayman

I think you are right....something is prematurely wearing and clogging up the works....I'm thinking it's not the TC though...

Not to say that isn't a problem, but that's not what is causing the shudder.

Also, the friction matrial is bad for the clutch packs, but that also isn't causing the shudder

[Klayman]

Originally Posted by crosive

Not to say that isn't a problem, but that's not what is causing the shudder.

Also, the friction matrial is bad for the clutch packs, but that also isn't causing the shudder

So the shudder is just the operation of the solenoids? Or the Bad TC?

[vidkidZ]

Originally Posted by crosive

Not to say that isn't a problem, but that's not what is causing the shudder.

Also, the friction matrial is bad for the clutch packs, but that also isn't causing the shudder

From what the mechanic working on the SS told me on Friday, GM thinks the shudder is a result of the buildup of moisture in the system that breaks down the fluid, gumming things up, etc. and they have been trying to find a fluid that prevents the moisture from forming.

This could be an educated guess or actual info. Either way it’s worth sharing.

[jcsuddre]

I just called Gm customer assistance line and told them about the issue I was having and informed them my dealer didn’t know anything about it . She proceeded to tell me she didn’t see any recalls or tsb out for this issue as well . Does anyone know of some kind of new tsb since the other one was elminated that they can look up ?

[egypt123]

I bought my 2016 SS used and haven't noticed the shudder. Bought it from a non-Chevy dealer so I have no info or contact with the previous owner. Is there any way to look up the service history on this thing to see if the previous owner took it in for this issue and what work might have been done?

[bturner2]

Car Fax???? Any GM dealer should have service history for work done at a GM shop based on your VIN,

[egypt123]

Originally Posted by bturner2

Car Fax???? Any GM dealer should have service history for work done at a GM shop based on your VIN,

Carfax didn't give me the complete service history. I've put in a call to a GM dealership and am waiting to here back.

UPDATE: Just so everyone knows, Carfax did NOT list service to the transmission. I called the dealership where mine was originally purchased and found the original owner had 3 services done for the shudder issue. The last one he had done in 8/2018 got the flush and a new TC put in. Hoping it doesn't rear it's ugly head again while I own it.

[gmw0181]

Originally Posted by jcsuddre

Is there a new tsb number for this flush ? I called my dealer and they tried to look up the 16na175 and it couldn’t be found . I see that it was eliminated when reading the update . My dealer told me they were not aware of the issue but then I described it to them and they scheduled me for an appointment to ride along so they can experience what I’m describing .

I seen this on this thread from another user doc: 18-NA-355 .

More info I found on this site: https://www.midenginecorvetteforum.c...ission-shudder

[jcsuddre]

Originally Posted by gmw0181

I seen this on this thread from another user doc: 18-NA-355 .

More info I found on this site: https://www.midenginecorvetteforum.c...ission-shudder

Thanks I’m taking it in tomorrow hopefully they will be able to look this one up .

[njweatherman]

@vidkidZ - Thanks for posting, good info

[pkincy]

The Dec 13, 2018 TSB 18-NA-355 is the new one. Nobody on Cadillac V fora or Corvette fora have been able to actual access a copy yet however. It is a 3rd "new" fluid from Mobil.

[pkincy]

Ok, here is some new info even though it is not the actual TSB:

Originally posted by GM Technical Assistance Center
8 Speed Torque Converter Shudder – New Service Procedure and New Mobil 1 Synthetic LV ATF HP Fluid Regional Rollout

GM CUSTOMER CARE & AFTERSALES

URGENT - DISTRIBUTE IMMEDIATELY
DATE 12/12/2018
SUBJECT 8 Speed Torque Converter Shudder – New Service Procedure and New Mobil 1 Synthetic LV ATF HP Fluid Regional Rollout
MODELS 8L45 and 8L90 Applications
TO All Cadillac, Chevrolet and GMC Dealers
ATTN Service Manager, Service Director, Shop Foreman, Service Technician, Parts Manager, Parts Counter Personnel, Warranty Administrator, General Manager
A new transmission fluid exchange procedure and new formula of Mobil 1 Synthetic LV ATF HP transmission fluid is being released to address torque converter shudder on 8L45 and 8L90 applications. The procedure and new transmission fluid is being rolled out regionally due to the limited availability of both the new transmission fluid and tool kit availability. The dealer rollout was determined by paid warranty claims from TSB 16-NA-175. It is anticipated that the new transmission fluid and tool kit will be available nationwide by late January or early February 2019. Once the new transmission fluid and tool kit is available the detailed service procedure will be loaded into GM Service Information (SI) as a Technical Service Bulletin (TSB). TSB's 16-NA-175 and 18-NA-177 will be eliminated from SI. An additional Global Connect Message will be sent to announce these changes.

Selected dealers will receive a separate Global Connect Message this week advising how to obtain the new Mobil 1 Synthetic LV ATF HP transmission fluid, delivery of the no charge tool kit from Bosch and detailed service procedure.

The new fluid exchange procedure will require the use of the existing DT-45096 TransFlow machine and tool kit. The tool kit will ship from Bosch at no charge.

The December 2018 Emerging Issues Broadcast, course number 10218.12V will be available through the Center of Learning on Thursday, December 13. The broadcast contains a video demonstrating the procedure on a Chevrolet Colorado and details on the new Mobil 1 Synthetic LV ATF HP transmission fluid.

The detailed service procedure may seem complicated at first review. However, we are confident that once you've completed the procedure you will find it relatively easy.

Proper Diagnosis: Sometimes shudder is not caused by the torque converter clutch (TCC). In some instances, shudder is fish bite, chuggle, surge or vibration. Utilizing the GDS and or the PICO Scope will help confirm the issue is TCC shudder. We have seen cases of suspected TCC shudder turn out to be engine performance, tire/wheel vibration or a driveline vibration.

Please do not contact the Technical Assistance Center (TAC) seeking information on when the new Mobil 1 Synthetic LV ATF HP transmission fluid and tool kit will be available nationwide. TAC does not have any additional information.

For those dealers that are not among the initial selected group. Please continue to follow 16-NA-175 and 18-NA-177 until the new service procedure is available nationwide. We are working diligently to get the new service solution available to all dealers and will advise through an additional Global Connect message once available.

Thank you for your cooperation.

GM CUSTOMER CARE & AFTERSALES

[MJinNC]

Got the new fluid yesterday, see what happens in a few hundred miles.