GM Buick/Oldsmobile/Pontiac/Full-Size 1975-1990 Repair Guide

Mufflers and Tailpipes



Place safety glasses over your eyes. These units are typically connected by flanges at the rear of the converter and at either end of mufflers either by an original weld or by U-clamps working over a pipe connection in which one side of the connection is slightly larger than the other. You may have to cut the original connection and use the pipe expander to allow the original equipment exhaust pipe to be fitted over the new muffler. In this case, you'll have to purchase new U-clamps to fasten the joints. GM recommends that whenever you replace a muffler, all parts to the rear of the muffler in the exhaust system must be replaced. Also, all slip joints rearward of the converter should be coated with sealer before they are assembled.

Place safety glasses over your eyes. Be careful to connect all U-clamps or other hanger arrangements so the exhaust system will not flex. Assemble all parts loosely and rotate parts inside one another or clamps on the pipes to ensure proper routing of all exhaust system parts to avoid excessive heating of the floorpan, fuel lines and tank, etc. Also, make sure there is clearance to prevent the system from rattling against spring shackles, the differential, etc. You may be able to bend long pipes slightly by hand to help get enough clearance, if necessary.

While disassembling the system, keep your eye open for any leaks or for excessively close clearance to any brake system parts. Inspect the brake system for any sort of heat damage and repair as necessary.