Jpena229

Amen brother, I've already had my TC and whole transmission replaced and now I'm getting a slight shudder at about 2,000 RPM when accelerating (normal driving not wide open) Checked with one of two dealers I've used for this tranny thing and they are telling me I have to go thru the complaint / I have a problem routine, that they can't just do it. I'm going to check with the other dealer and see what they say, but like Maxie2U said, looking at the procedure I'm sure they're going to screw something up.

Classic-Chevy-Guy

If you had the triple flush done in the past, should you have it done again with the new tranny fluid?

Seems that this TSB makes no reference to superseding the previous one.

kensredvette2

^^^
You should have the triple flush done again - the new fluid with the blue banner bottle has lower moisture pickup (according to GM). The new TSB is all about the fluid composition difference, not just having 'fresh' fluid. And, according to GM, the previous versions of fluid WILL pick up moisture over time thus changing the friction properties that lead to the shudder.
The 'vette procedure in the 18-NA-355 is essentially the same as the first version of 16-NA-175 -- both call out the triple flush. (A fluid flush done by dealers to resolve the shudder problem within the last 6 months or so was very likely a single flush, which is not nearly as effective at clearing out old fluid as 3 successive fluid changes. The TSB '175 was changed to a single flush procedure along the way a few months ago.)

IMO, the fluid change procedure for vettes in the '355 TSB may be the easiest of them all in that document. It says - 'Drop pan - replace pan - fill - circulate fluid;; repeat;; then fill a 3rd time and do the check level procedure.
The check level procedure has not changed from what I can tell.

NSC5

It is interesting that part of the TSB references prepping the flush machine if it currently has Dex VI fluid in it but doesn't mention the original Dex HP that was the original design/factory fill fluid for the 8L90 or the first revision of Mobil ATF that came prior to the latest version of Mobil ATF.

We complain when dealers throw parts at a car trying to fix a problem but corporate doesn't seem to be doing any better with this shudder issue after throwing multiple torque converters, different flush and fill procedures, and 3 different fluids at an issue that has been going on for 4 years now.

chevy corvette

How many 2019 Z06 A8 having this shudder problem?

djyankees31

How long does it take? The dealership I use said I need to leave the Corvette all day for the PICO testing, approval, and work.

Maxie2U

GaryPitts

Do we think the new fluid will help the RPM fluctuations? I've always assumed that was a bad TC. When I had my flush done over a year ago, it fixed the shudder right away, but the RPM still varied. Had to get a Range to stop that...

Tinkertech

The factory started using Mobil 1 Syn ATF on production cars on 1-23-17 according to Tadge.
This is the 'First' version of the Mobil 1 Syn ATF.

MA ZO6

My dealer told me he needed to have it for the day but it was done in 4 hours. GM makes them do the PICO test to prove it has a problem or GM may not pay for the warranty work if the dealer is audited by GM. My car had the sudder problem REAL bad so the tech only had to go for a quick ride before the pico meter showed it had the problem. I think all dealers would rather tell you all day in case they run into any problems.

tertiumquid