GM 25878015
Muffler & Pipe

To get the Muffler out of the way you will need to raise and support the vehicle which you should not overextend the rear brake hose. Lift off the lower shock absorber nuts and bolts , right rear leaf spring nut to remove bolt . Insert a block of wood between the frame and the rear axle. Next is withdrawal of nuts fixing Muffler to the Catalytic Converter without oily lubricants. Spray a soapy solution to the exhaust pipe hanger rods to make it easy to remove the exhaust hangers and pry the hangers free. Pry the Muffler back from the Catalytic Converter, turn it 90-degree counter clockwise and gently slide it up from the car. For installation, with the Muffler turned 90 degrees ccw, slide it over the rear axle so that the flange will be close to the catalytic that position and rotate it clockwise to the installed position and slide the forward to align with the studs with the rear of the catalytic, avoiding to use oil-based lubricants. Apply a soapy solution the inside of the wooden exhaust pipe hanger and the exhaust pipe hanger rod of wooden type so that to make the installation process move smoothly, then press up the hanger over the rods. Mount the nuts for the Muffler to the Catalytic Converter; tighten them using a hand till they touch the metal flange; and then to 45 nm (33 ft. Lbs.). Then, remove block of wood out from between the frame and rear axle, install the right rear leaf spring bolt and nut, tighten bolt and nut to 85 nm (63 ft. Lbs), then install the lower shock absorber bolts and nuts tighten them to 95 nm (70 ft. Lbs). Lastly, check on the exhausst system for leaks and underbody contact prior to the lowering of the vehicle.

To replace the exhaust Muffler on the items with llv or llr engines (2.9L, 3.7L), first lift the vehicle and support it, being careful to not extend too much the rear brake hose. Remove low left & right shock absorber nuts and bolts, low rear leaf spring nut and bolt, and winter edge of block of wood between the frame and rear axle. Make sure not to over-flex or damage the flex joint in this process. Second, take off the nuts that hold the Muffler to the Catalytic Converter, without using oil lubricants. Squirt some soapy water on the exhaust pipe hanger rods to make it easy to take the exhaust hangers out and pry out the hangers. To remove the Muffler slide it rearward from Catalytic Converter, rotate it 90 degrees counterclockwise and pull it out of the vehicle carefully. For installation, with Muffler turned 90 counterclockwise slip it over the rear axle until the flange is close to catalytic convertor, then turn it clockwise 90 as for install position and slide it forward, align the studs at the rear of catalytic convertor. Again, avoid oil-based lubricants. Using a soapy solution facilitate the installation by wiping it on the inner diameter of the exhaust pipe hanger and the exhaust pipe hanger rod then pressing them on to the rods. Tool the nuts holding the Muffler to the Catalytic Converter in hand until they touch the metal flange, which is to be tightened to 45 nm (33 lb ft). Remove the block of wood, install the nut on the bolt in the right rear leaf spring and tighten 85 nm 63 lb ft. Finally install and tighten the lower shock absorber bolts and nuts to 95 nm (70 Lb ft). Lastly, check the exhaust system for leaks and underbody touch before lowering down the vehicle.

To replace the exhaust Muffler for llv/llr vehicles with 2.9l/3.7l engines, first lift and support the vehicle without overextending the rear brake hose. Start with the removal of the lower shock absorber nuts and bolts , then remove right rear leaf spring nut and bolt . Put a piece of wood between the rear axle and the frame without being over-flexed or run the risk of breaking the flex joint. Then, remove the nuts that attach the Muffler to the Catalytic Converter with no use of oil-based lubricants. Spray the soapy solution to the exhaust pipe hanger rods in order to make the removal of the exhaust hangers easier, pry the hangers out. To remove the Muffler, slide it towards the rear, rotate it 90 degrees counterclockwise and carefully remove it from the vehicle. For installation, rotate the Muffler 90 degrees counterclockwise and insert it over the rear axle and slide it back until the flange is near Catalytic Converter and then rotate it clockwise 90 degrees to the position installed and slid it forward until the stud aligns to the rear of Catalytic Converter. Again, avoid oil-based lubricants. Use a soapy solution to lubricate the inner diameter of the exhaust pipe hanger and the exhaust pipe hanger rod in order to make the installation of the hangers easier, follow by pressing in on the rods. Screw the nuts holding the Muffler to the Catalytic Converter on with hands only until it touches the metal flange before tightening to 45 nm (33 lb ft). Remove that block of wood , then install the right rear leaf spring bolt and nut to 85nm (63 lb ft) tightening and install the lower shock absorber bolts and nuts to a 95 nm (70 lb ft). Finally check for leaks in the exhaust system and underbody contact before lowering the vehicle.

Apply a soapy solution to facilitate the removal of the exhaust hangers, then pry the hangers free.

Slide the muffler rearward from the catalytic converter, rotate it 90 degrees counterclockwise, and carefully pull it out.