The dealer did the TSB (PIP5337A dated Jan. 22, 2016) double ATF flush and replace trans filter on my 2015 Sierra Denali 6.2L w/8-sp trans. Shudder is gone and has not returned in 1,000 miles. There is a new torque converter in the works to correct this condition. When it will be available is not known. You have to keep after the service dept in you dealer. Mine are great, they will do just about anything to please the customer.
Note – Replacing the trans for the shudder does no good because the same torque converter that causes the problem will come with the new transmission so nothing will be accomplished. Tell them to pull up that TSB. The dealers don;t commit every technical service bulletin (TSB) to memory and without an accurate description from the owner may not provide them enough information to search the data base for all issues. In other words, they give up to easily and start throwing parts at it such as a new transmission.
