Transmission Disassembly: Transmission
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, 2003 Chevrolet Cab & Chassis Silverado, and 2002 GMC Sierra. However, it is still accessible from the selected car via links, so may be relevant.
- Drain transmission fluid. See DRAINING AND REFILLING article in SERVICING article.
- Disconnect external wiring harness from main electrical connector, 3-speed sensors and Neutral Start/Backup (NSBU) switch, if equipped. Disconnect linkage from transmission shift lever. Leave shift lever and NSBU switch on transmission. Disconnect any PTO wiring connections, if equipped. Disconnect parking brake linkage, if equipped.
- Block wheels before disconnecting driveline, unless vehicle is on a lift or jack stands. Disconnect vehicle driveshaft from transmission output flange or yoke. Uncouple PTO from transmission and/or from the PTO drive shaft.NOTE: It may be necessary to remove an engine torque converter housing access cover to remove flexplate or flexplate adapter bolts. This is the engine-to-transmission connection.
- If transmission mountings support rear of engine, place support under engine. Also support transmission with a suitable hoist or jack. Remove all bolts, nuts, washers, spacers and supports attaching transmission to vehicle and engine.WARNING: Ensure torque converter moves rearward with transmission during removal. DO NOT allow torque converter to become disengaged from oil pump, or it will fall, causing damage and/or injury.CAUTION: DO NOT pull transmission away from torque converter assembly. Torque converter drive cover must be entirely free of flexplate drive or crankshaft pilot when transmission is separated from engine.
- If equipped with a No. 2 torque converter housing, move transmission away from engine about 1.36" (34.6 mm). If equipped with a No. 3 torque converter housing, move transmission away from engine about 1.74" (44.2 mm). Ensure transmission is completely clear of engine. If equipped, remove adapter ring and/or gasket.
- Carefully remove transmission assembly from the vehicle. Position transmission on a workbench, with oil pan downward. Remove PTOs, PTO covers and gaskets, if equipped. Install Repair Stand Adapter Plate (J-44723) or equivalent, on Repair Stand (J-29109) or equivalent. With transmission attached to a sling, move transmission to adapter plate and secure in place. See Fig 1. Remove sling from transmission.