There may not be any transmission movement after replacing the transmission valve body on some 2015-2017 Escalade, Yukon Denali; 2015-2019 Corvette; 2015-2021 Silverado, Sierra; 2016-2018 CT6; 2016-2019 ATS, CTS; 2016-2021 Camaro; 2017-2021 Colorado, Express, Canyon, Savana; and 2020-2021 CT4 models equipped with the 8L45 automatic transmission (RPO M5N, M5T) or 8L90 automatic transmission (RPO M5U, M5X, MQE). The no movement condition may be due to the incorrect 1-2-7-8-R clutch fluid passage seal being installed or the seal is missing.
If the 1-2-7-8-R clutch fluid passage seal was installed during the valve body replacement, it will be necessary to remove the transmission valve body and measure the length of the seal to make sure the correct seal was installed.
The clutch fluid passage seal on the 8L45 transmission does not have any ID notches and the seal is 33.5 mm tall. (Fig. 19)
Fig. 19
The clutch fluid passage seal on the 8L90 transmission has five ID notches and the seal is 23.1 mm tall. (Fig. 20)
Fig. 20
For more details and parts information, refer to #PIP5784.
– Thanks to Terry Neuendorf
