2017 6.2L 8spd 1-2 Shift Clunk Fix

Krusty · August 2, 2018

Pretty much been living with the 1-2 shift clunk since new, 12,000 miles on her now. Thought she was due for oil change mileage wise, made appointment for service, snapping drivers side armrest and clunky tranny. Turns out it was only at 26% on the oil - they changed it anyway. Snapping sound from arm rest - new part on order. 1-2 clunk they did a "drive learn" per bulletin PIP5437B and 16-NA-019. So far - so good.

When I picked her up I asked if they thought driving it around town in M7 (to keep her out of V-4) affected shift "learning", and they recommended against it. Said it will be "relearning" my driving habits for 2,000 miles. So probably not going to use manual mode except when needed for grade braking, towing etc. Told them these trucks need a switch to turn off V-4.........

Still loving the 6.2L and Flowmaster 53553 muffler.

L86 All Terrain · August 3, 2018

They wont put a V4 button in because the EPA wouldn't allow it without re-certifying the economy.

GM's trans tuning sucks. I am now getting a delayed shift from park to reverse with a cold transmission. Never did it for the first 30,000kms. I have a 15 so I am getting it tuned, not sure if they can tune the 2016+ transmissions easily.

Crobinson16 · August 4, 2018

10 hours ago, 10SierraA.T. said:

They wont put a V4 button in because the EPA wouldn't allow it without re-certifying the economy.

GM's trans tuning sucks. I am now getting a delayed shift from park to reverse with a cold transmission. Never did it for the first 30,000kms. I have a 15 so I am getting it tuned, not sure if they can tune the 2016+ transmissions easily.

There is a TSB for the delayed shift during first start up.

Logroller · August 4, 2018

On 8/2/2018 at 6:30 AM, Krusty said:

Pretty much been living with the 1-2 shift clunk since new, 12,000 miles on her now. Thought she was due for oil change mileage wise, made appointment for service, snapping drivers side armrest and clunky tranny. Turns out it was only at 26% on the oil - they changed it anyway. Snapping sound from arm rest - new part on order. 1-2 clunk they did a "drive learn" per bulletin PIP5437B and 16-NA-019. So far - so good.

When I picked her up I asked if they thought driving it around town in M7 (to keep her out of V-4) affected shift "learning", and they recommended against it. Said it will be "relearning" my driving habits for 2,000 miles. So probably not going to use manual mode except when needed for grade braking, towing etc. Told them these trucks need a switch to turn off V-4.........

Still loving the 6.2L and Flowmaster 53553 muffler.

Are you saying all noticeable shifting is completely gone or just the bigger annoying clunk? Meaning do you still notice a slight shift abnormality (not the clunk crap, but something) at the slow speeds or are all gears like butter now?

Krusty · August 5, 2018

21 hours ago, Logroller said:

Are you saying all noticeable shifting is completely gone or just the bigger annoying clunk? Meaning do you still notice a slight shift abnormality (not the clunk crap, but something) at the slow speeds or are all gears like butter now?

Certainly no clunking - been sticking to no unnecessary M mode - but only a few days driving since fixed. With the louder muffler it helps to hear the shifts by RPM change. You want to talk butter - our 2015 and now 2018 Subaru Outback sure shift seamlessly - U never know when they shift..........

Logroller · August 5, 2018

Every once in awhile I will get a low level clunk, but the conputer has cleaned it up since It started out. However, I feel my mastering of the gas pedal was the real cure. It's second nature to me now.

My gears are pretty buttery on the top side. But never have been on the low end of the gears, but not that rough either. I'm just glad I don't get annoyed daily by that conputer goofing up with the low gear clunk crap.

But now I gotta prove to the dealer to get rid of this squeaky clunk crap from the leaf springs/yoke/shocks. It might be one, two or all of them.

L86 All Terrain · August 7, 2018

On ‎2018‎-‎08‎-‎03 at 9:24 PM, Crobinson16 said:

There is a TSB for the delayed shift during first start up.

Thanks, sounds like I need a new stator shaft support, which requires pulling and tearing down the transmission. Awesome. Maybe I can talk them into a new torque converter while they are in there. Looks like I wont keep this truck too much longer.

Edit: here is a link to the TSB if anyone is having the same issue. https://www.revbase.com/BBBMotor/TSb/DownloadPdf?id=195114

Logroller · September 27, 2018

On 8/4/2018 at 5:12 PM, Krusty said:

Certainly no clunking - been sticking to no unnecessary M mode - but only a few days driving since fixed. With the louder muffler it helps to hear the shifts by RPM change. You want to talk butter - our 2015 and now 2018 Subaru Outback sure shift seamlessly - U never know when they shift..........

Ugh, mine is getting worse again, no horrible, but not better. Doing it at 40mph now. Very minor, but I notice it.

Krusty, what the progress report still smooth or smoother?

Krusty · September 27, 2018

11 hours ago, Logroller said:

Ugh, mine is getting worse again, no horrible, but not better. Doing it at 40mph now. Very minor, but I notice it.

Krusty, what the progress report still smooth or smoother?

Nope - Right back to low level clunking - even down shifting to 1st sometimes feel it. Seems to be the new norm with GM......... As my salesman says...... "They all do it"..................