A8 Shudder, etc. TSB 18-NA-355
 

Might be here, but had a time finding it, it is 17 pages long.

Printed it out and taking it with me for the dealer.

https://static.nhtsa.gov/odi/tsbs/20...63890-9999.pdf

Not sure if I’m having the rumbling or shudder issue, I’ve noticed when on manual and decelerate to 1st gear the car noticeably jolts. Not sure if related.

From my understanding the shudder is only when you're in a higher gear and steady throttle or lightly accelerating

I've posted this link in several threads, including the TSB Sticky in this subforum.

Anyone able to point me to the TSB where they are to replace the converter or whatever as my dealer is refusing to do so as they cannot replicate the issue.

Thanks.

Sorry, I can not help with that. Last I heard, it was probably no way they replace the TC.

What I can note is, I told my service department if they were unable to duplicate the problem, I wanted to schedule an appointment for them to do a 'ride-along', with me driving the car. And not have it just returned to me, unchanged. (Since I could duplicate the problem almost on demand.)

As for the rest, on the second visit, they duplicated the problem and did the flush. I'm a few thousand miles past that and, luckily, has not returned. I also scheduled a ride along for when I picked it up, for assurance that it was actually fixed.

For what it's worth.
It's a pita, but keep after it. :mad:

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 it

Here is the down side.

They did the fluid change, it came back within 500 miles.

Now they are saying they can't re-duplicate it therefore nothing is being done.

Had thought that if it returned after 500 miles that the next remedy was replacing the TCC, clearly I am wrong.

In your case this is the dealer not wanting to eat a second round of repair. They have to warranty the repair for 12/12 that they got paid from GM for. A return to the dealer for the same problem, means its coming out of the tech's and the dealer's pocket. The tech likely doesn't want to do the repair again on his own dime.

The kicker is no other dealer will touch it until after that 12/12 goes by. They would also be paying out of pocket for the repair because the other dealer would be expected to redo the repair under their warranty. This is the shit part of dealers. You are best served to suck it up buttercup, and pay for an aftermarket TC to be installed. No more shudder.

Not following, are you meaning December 12th?

And if I install an aftermarket TC won't that void the warranty?

I would open a case with GM Customer Assistance. With my Colorado when the shudder came back after the #18-NA-355 flush they replaced my TC.

No 12/12 means 12months, 12 thousand miles. Thats the warranty that comes with dealer repair work. If they repair your car under warranty of if you pay cash for the repair, they offer a 12 month 12k mile warranty on those repairs. They are obligated to redo the repair if it didnt fix the problem, or it broke again.

When driving the A8 in manual mode there is never a need to downshift to 1st gear when slowing down. Downshift only to 2nd gear and let the car downshift to 1st when it's ready.

ScatPack is correct. Techs are paid flat rate, so if there is a mistake they need to fix it with no pay for fixing it as they received pay for the first fix. It is their responsibility, but it does not make the dealer or the tech any additional compensation, so the "run around" is usually given.


Now, on the shudder issue and the fluid flushes. The symptom is from the stock converters poor design. The flush is only a bandaid intended to get you past the warranty period, and then it is no longer a liability to the auto maker. The shudder is from the fluid aerating and then it cannot provide the clamping pressure for the clutches and steels, and the metal HCI2000SS found is from the damaged caused by the shudder, and all will have this damage depending on how long the shudder was present. ONLY a good proper designed aftermarket converter can correct the cause. GM does not want the expense of replacing the torque converters so very few are able to get this under warranty, and it is just the same design they replace it with, again NOT addressing the cause, only the symptoms. There are a few proven brands that correct it all AND increase acceleration substantially, but if the symptoms have been present for any length of time, wear and damage very likely has already started.


Anyone that wants to source one of the proven aftermarket units, email our Engineering department directly: Tech@EliteEngineeringUSA.com


Hope this helps!