2015 Yukon 6.2-Listen to this noise- dealer says $5k for new TX

[07denaliyuk]

Looking for help with diagnosis and fix

2015 XL 6.2 with 6l80e
Transmission shudder driveline Noise at 1/3 throttle at all speeds after engine is warned up. No OBD codes

- TX mechanic ruled out the torque converter, wrong area for noise
- no metal in the oil
- no codes
- tachometer jumps 3-400 rpm when noise happens.
- u-joints are all good shape

Noise on highway

Noise with Camera in 3rd row

 

[Big Mama]

I’m not much help here but others will chime in. Welcome to the forum from Virginia.

 

[Tiredmechanic23]

Was the trans pan dropped? Any mods, tunes, etc to the vehicle? Where was the noise pinpointed to by the tech? did he listen from under it or only when driving or operating? I ask this as noise can echo and sound like its in one area but be in a completely different area in reality.

 

[mb1500]

Strange. Does it go away without throttle input?

 

[gat0r]

hadnt heard that ...yet


sounds like mechanic needs to move around inside while you are driving.
maybe use a gopro underneath too

 

[tirekicker]

i didn't know you could get the 6l80 with the l86. is it one of the very first production run?

 

[Doubeleive]

i didn't know you could get the 6l80 with the l86. is it one of the very first production run?

the first 6 months production had the 6 speed

 

[tirekicker]

interesting....

 

[07denaliyuk]

Strange. Does it go away without throttle input?

It’s intermittent, it goes away without throttle input.

 

[07denaliyuk]

Was the trans pan dropped? Any mods, tunes, etc to the vehicle? Where was the noise pinpointed to by the tech? did he listen from under it or only when driving or operating? I ask this as noise can echo and sound like its in one area but be in a completely different area in reality.

Have not dropped the pan yet, likely this week.
No modifications to the engine or transmission, all stock.
The dealer tech only drove it a few miles, I don’t know if they put an real effort into diagnosing it. It’s likely they deemed it a torque converter since they fail at a high rate and just said ‘new trans’.
Local trans guy initially said torque converter but after a test drive, he hadn’t heard this issue before. He thought possible electronic issue in valve body.