2017 transmission fixes - do they work?

[YukonXLPerson]

I’m considering buying a pre-owned 2017 Yukon XL Denali this weekend. I noticed a chunky or rough shifting from 1st to 2nd gears, came home to research and found this thread: 

Wondering if anyone has gone through the re-program, fluid flush and/or torque converter change. Did any of these solutions fix the problem and has it held up? 

 

 

[mjm-1957]

Do not buy anything with the M5U 8speed transmission. Cant fix the unfixable. Absolute  ****** and nothing but a problem.

[Ivan_Drago]

On 9/3/2020 at 10:06 PM, YukonXLPerson said:

I’m considering buying a pre-owned 2017 Yukon XL Denali this weekend. I noticed a chunky or rough shifting from 1st to 2nd gears, came home to research and found this thread: 

Wondering if anyone has gone through the re-program, fluid flush and/or torque converter change. Did any of these solutions fix the problem and has it held up? 

 

 

I have a '17 XL (non Denali) with the 6-speed and also had harsh shifting. GM warrantied my transmission for a full rebuild and new (updated) torque converter. So far almost 20,000 miles after the repair and so far so good. GM gave me a 2 year unlimited mile warranty on the repair.

[Ivan_Drago]

note: the above issues started at mid 50k miles and were repaired at 62k miles