This bulletin applies to 2010-2011 Buick LaCrosse and 2011 Buick Regal vehicles equipped with six-speed automatic transmissions. The vehicle may exhibit a slip or flare in reverse gear, no reverse gear, slip or flare in third gear or no third gear.
The MIL may be on. DTC P0776 may be found as an active or history code in the TCM. The condition may be caused by a broken 3-5-R apply (waved) plate. It is recommended that a new 3-5-R piston and wave plate be installed any time the transmission is disassembled for any reason.
Debris generated by the condition must be cleaned from the entire transmission and the pump fluid filter and the control solenoid filter plate must also be replaced. These parts are included in the seal kit.
The notches in the 3-5-R piston were removed during the 2011 model year. Be sure to replace any 3-5-R piston with notches when repairing a broken 3-5-R wave plate or any time the transmission is disassembled for service.
