Another 8spd question. How to handle dealer? 2017 Sierra, 6.2 8spd

[MattyB4x4]

Hi all,

 

Truck is a 2017 Sierra Max Trailering edition with the 6.2, 8 spd and about 34,000 miles on it.

 

I bought the truck in 2019 and have taken it in 4x now over the last 20,000 miles for clunky shifting.  I had the shuttering issue early on, but that was fixed.

 

Now under low throttle, when in traffic, or leaving my driveway on a downhill...the truck likes to clunk into 2nd gear.  It's not every time, but I feel like it happens at least once per trip but only under light throttle.

 

This morning as I was coasting up to a light, it turned green and it slammed so hard into 2nd gear that the tires chirped.

 

How are you guys handling a dealer that can't replicate the hard shifting/clunk into 2nd gear on the 8 spd?  I love the truck but quite frankly, this crap is getting old.  I'm worried about premature failure, etc - though the tech at the dealer has said "You have a paper trail"....but I trust that as far as I can throw him.

[swathdiver]

If yours were mine I would data log until the issue replicates and then show it to the dealer/technicians.

 

We had a banging issue with a FWD transmission once.  It was the input clutch piston.  The tech could not replicate, so we put him in the car and had my wife drive it and before we even pulled onto the road, it was replicated and he knew what it was.  His driving style, my driving style could not replicate the issue.

 

MDI2 adapter connected to a laptop running GDS2 software.  There are other less expensive options if you research or ask around.

[JimCost2014]

1 hour ago, MattyB4x4 said:

have taken it in 4x now over the last 20,000 miles for clunky shifting.  I had the shuttering issue early on, but that was fixed.

You did not say what has been during those visits, or how the shuttering issue was fixed by the dealer.

 

Have they swapped the fluid to the new one?

[MattyB4x4]

13 minutes ago, JimCost2014 said:

You did not say what has been during those visits, or how the shuttering issue was fixed by the dealer.

 

Have they swapped the fluid to the new one?

 

Hi, sorry about that. 

 

1st visit was a "relearn" - I guess they reset the TCM and let it relearn my driving style?  Shutter issue happened a few months later on a road trip so I took it in for visit #2.

 

2nd visit was a flush and new fluid - shutter was gone, but it still had the occasional hard shifting.

 

3rd visit was a flush and new fluid - still hard shifting about once per trip. 

 

4th visit was nothing - they couldn't replicate the issue so they did nothing.

 

 

 

[MattyB4x4]

1 hour ago, swathdiver said:

If yours were mine I would data log until the issue replicates and then show it to the dealer/technicians.

 

We had a banging issue with a FWD transmission once.  It was the input clutch piston.  The tech could not replicate, so we put him in the car and had my wife drive it and before we even pulled onto the road, it was replicated and he knew what it was.  His driving style, my driving style could not replicate the issue.

 

MDI2 adapter connected to a laptop running GDS2 software.  There are other less expensive options if you research or ask around.

I hadn't thought of that.  I don't know much about data logging but I'll look into it.