rkhegler

Been driving my C7 for about two weeks after the flush, new wire harness, and sensor replacement. Seems to be driving much better. For hoe long, I do not know. Have to take it back to the dealer for a re-evaluation.

mpdugas

Is there any way we could get this raw data in sortable format, like by car type, or beginning mileage, just to mention a couple of examples? When I view the data set, the order is fixed.

I don't use Google office tools ( I am undergoing a Google exorcism atm), so I am hoping this can be exported as a comma delimited file?

Thanks for this effort, btw, it factors heavily in my consideration of buying a new C7 with A8.

MidLife+

FYI - I have a two year old Z06 that has been in the shop for the transmission fluid flush, torque converter change and transmission valve body changed @ 20K miles.
With that said, I would buy this car again. I enjoy it so much I look for excuses to drive it. Even on cold cloudy days like today I will take the four mile trip to the gas station to top it off, after a couple hours and hundred miles or so I remember to get gas and go home.

The A8 has annoyances that will be corrected (5 year warranty). I can't see the problem ever resulting in being stranded on the road.
Data is a good thing but remember the metadata source!

mountainears

The data can be sorted and filtered on the web page and it can be exported. You can also copy/paste the data into Excel. What are you looking for specifically that isn't already shown on the sheet or in the charts?

speed4tu

I would consider it very heavily before jumping out there in it. Me personally having the A8 and now the issues with it and dealing with it. I will never buy another GM product with the A8 in it.

mpdugas

I'm sorry, I tried to do some manipulations using my MS techniques, which Google doesn't employ; thanks for suggesting that I look closer. I have it 'sorted' out now.

MA ZO6

I have done some searching on the internet about what the new procedure GM will come out with next year to resolve the shudder problem with the 8 speed transmission. I have found some information from people who claim they have inside information that GM will come with a new fluid and a new procedure to flush the fluid. The below information is from the GM techlink website and it seems to support that, I highlighted it in red at the end of the article.

My car already had the fluid flushed about a month ago and it did NOT solve the problem, hopefully the new procedure they come out with next year will fix it for good.
John

Changes in Transmission Oil Cooler Flush Requirements

Posted on November 20, 2018 by blogadmin

Recent GM studies have shown that automatic transmission oil cooler flush requirements have limited benefit on many current transmission repairs. Based on the studies, GM will no longer require a mandatory flush and flow test of the transmission oil cooler and the oil cooler pipes — including the auxiliary transmission oil cooler, if equipped — to be performed in every instance of transmission or torque convertor replacements or internal transmission repairs. (Fig. 1) As a result of this policy change, transmission repairs will be simpler, the environmental impact of waste oil will be reduced and Global Warranty Management transaction processing will be simplified.

Fig. 1



Transmission Repair Policy Changes

Effective December 1st, 2018:

• Job cards will no longer require a transmission flush code from the DT-45096 Transmission Oil Cooling System Flush and Flow Test Tool (DT-45096 TransFlow®machine). (Fig. 2)
• The Flush Code field in Global Warranty Management related to all applicable transmission labor operations should be left blank. The field will be eliminated mid-December.
• The Warranty Support Center will no longer require a flush code on warranty transactions.

Repair procedures in the Service Information will be updated to reflect the elimination of the transmission cooler flush requirement. In addition, related service bulletins, the labor time guide, and the GM Service Policies and Procedures Manual will be updated accordingly.

Fig. 2

The DT-45096 TransFlow machine continues to be a valuable GM Essential Tool that should be used when diagnosing transmission overheating conditions or a transmission failure due to a lack of lubrication. Technicians should continue to document the TransFlow code in the correction comments of the job card in instances when the DT-45096 flow test procedure is used to diagnose an overheating or lubrication concern.

TIP: Use only the appropriate GM automatic transmission fluid when performing a transmission repair. If the fluid in the DT-45096 TransFlow machine is different than what is used in the transmission, after performing the flush and flow test, use compressed air to blow the residual transmission fluid out of the transmission oil cooler and lines.

New Fluid Exchange Procedure

A new repair procedure for the DT-45096 TransFlow machine to exchange fluid also has been developed to address torque converter clutch shudder on 8L45 and 8L90 8-speed automatic transmissions (RPOs M5T, M5N, M5U, M5X). The new transmission fluid exchange procedure and new formula of Mobil 1 Synthetic LV ATF HP transmission fluid is being rolled out regionally due to the limited availability of both the new transmission fluid and tool kit. It is anticipated that the new transmission fluid and tool kit will be available nationwide by late January or early February 2019. Look for more information to be released soon in a service bulletin and the December 2018 Emerging Issues seminar (10218.12V).

– Thanks to Mark Gordon

Updated December 13, 2018

NSC5

Great, another different modified fluid attempt to mask the underlying issues. I was hoping for a real fix and not the latest serving of magic mouse milk.

Maybe GM will just send us all a container of this for the first quarter of 2020 attempted fix:

Maxie2U

NSC5

Throwing fluid formulation #3 at it four years after it was introduced is pretty sad. This product may set a GM record for the most TSBs for the same problem.

GM has been making clutch to clutch automatic transmissions with lockup converters for a very long period of time so why they can't solve this issue is a mystery at least to their customers.

Z QQH 6

I'm late to this party and I don't have the problem ,yet. I don't know if someone else has thought this but I suspect it has a lot to do with the AFM system. Maybe be the trans/convertor can't handle or accept torque changes under AFM. When Cadillac tried this in the past it too was a disaster and they dropped it pronto. I don't recall if they had a trans or engine problem.

jcthorne

Cadillac did not drop AFM and uses it to this day. So do other GM products including the GMC Trucks.

Texan1Z06

kensredvette2

This new procedure seems all about making the fluid change easier with less shop labor. Reading between the lines in the GM notice, IMO, a likely possibility is a new tool/fixture to be permanently placed in the tranny fill port that includes a tube to be able to vacuum out the old fluid, then pump new fluid in. The check level port on the tranny pan still being used to check level. OR,,,,, a new tranny pan with BOTH check level and drain ports to do the fluid swap.

Remember GM already changed to only 1 fluid swap instead of 3 and deleted the need for a new filter when doing a swap. Deleting the need to check flow through the cooler is a big step towards simplicity.

With a 'fluid of the month policy', performing the fluid swap needs to be as simple (inexpensive) as possible. Shop labor to drop the pan is not cheap.

The 'vacuum out the old fluid' has been mentioned by others already in this forum - not a new idea. But GM may make it easier to do fluid swaps for both GM and DIY'ers trying to do preventative or scheduled maintenance.

Z QQH 6

My reference

Cadillac L62 V8-6-4[edit]

First experiments with multiple-cylinder engines during WWII,[3] were re-attempted in 1981 on Cadillac's ill-fated L62 "V8-6-4" engine. The technology was made a standard feature on all Cadillac models except Seville, which had the 350 diesel V-8 engine as a base engine. Cadillac, in conjunction with Eaton Corporation, developed the innovative V-8-6-4 system which used the industry's first engine control unit to switch the engine from 8- to 6- to 4-cylinder operation depending on the amount of power needed.[3] The original multi-displacement system turned off opposite pairs of cylinders, allowing the engine to have three different configurations and displacements. The cars had an elaborate diagnostics procedure, including showing engine trouble codes on the air conditioning display. However, the system was troublesome, misunderstood by customers, and a rash of unpredictable failures led to the technology being quickly retired.[3]

speed4tu

My thoughts exactly on this matter. I had enough of GM's crap several years ago and quit buying any GM products for about 10 years. Im thinking this C7 purchase may do it for me again. Have a beater Cruze with an ongoing coolant leak, the Corvette with ongoing A8 issues. My non GM vehicles moving on trouble free. I love the Corvette but their build quality and durability is just pure junk. Maybe the upcoming Shelby Mustang is in my future. Never any issues with multiple Ford products.

myfunweecar

So new member, had my 2016 Z51 for right at 2 years and 7700 miles. Had the shudder, took it in, fluid change and is fixed for the moment. What I think I did notice was the following. I may be crazy Prior to the shudder, if I coasted and watched, V8 mode would begin on a coast when it shifted from 5th to 4th. After the shudder, I noticed cases where it was still in V4 mode in 4th. And I am still noticing that. Does anyone without the shudder notice if the engine is in V4 mode when the tranny has downshifted into 4th? I am sure it could be I just never noticed, but being somewhat OCD I usually notice this stuff. Oh, I am always in sport mode if that makes a difference.

pkincy

Check TSB 18-NA-355. I believe it is the new TSB for the updated Mobil 1 ATF.

Z QQH 6

I have a question for y'all. I have only 1500 miles on my A8 and have not obviously been on a long trip. I have yet to see V4 indicator. How long must one drive, distance wise, to have this go active?

NSC5

With a non-Z06 C7, the control system is very aggressive about going into V4 mode and will do so at fairly low road speeds as soon as the engine is warmed up. There is no dedicated indicator for V4 so you have to be in the fuel economy DIC page (maybe other pages also show it?) to see the V4 and V8 annunciators appear.

A Z06 goes into V4 mode only under very limited conditions and the ZR1 wasn't cursed with this system at all.

I wasn't a big fan when Ford started putting the small displacement turbo-charged "Eco Boost" engines in their light duty pickups but they have performed well and for most applications I would take one of those in a heartbeat over this flawed AFM system which provides minimal fuel economy gains at the cost of torque converter issues and generally reduced driving satisfaction.