Repairing a broken clutch wave plate
A harsh shifting condition on select GM vehicles may be due to a broken 35R clutch wave plate. Applicable vehicles include 2007-2009 Saturn Aura and Outlook, 2008-2009 Saturn Vue, 2007-2009 GMC Acadia, 2007-2009 Pontiac G5, 2008-2009 Pontiac Torrent, 2008-2009 Buick Enclave, 2008-2009 Chevrolet Equinox and Malibu, and 2009 Chevrolet Traverse (all equipped with the 6T70/75 6-speed automatic transmission.
The condition may include the Ses light and/or no reverse, and a slip/flare or harsh shifts in drive range 3rd and/or 5th gear. Codes P0776 Clutch Pressure Control (PC) Solenoid 2-Stuck Off and P0842 Transmission Fluid pressure (TFP) Switch 1 Circuit Low Voltage may be set.
A broken 35R clutch wave plate allows the piston to overstroke, causing the piston to leak and causing loss of apply on vehicles with more than 25,000 miles.
During the repair process, it is important to install the wave plate in proper orientation to prevent the possibility for the failure to reoccur. Install the rounded edge of the wave plate internal splines facing the 35R piston.