1649633 Muffler Fits Caterpillar 2W5932 578 583R 8A 8 D8N D8R D8R II 57HOne New Aftermarket Replacement Muffler Fits Caterpillar (Fits CAT) Track Type Tractors and Pipelayers This aftermarket replacement muffler Fits Caterpillar D8N, D8R, and D8R II track type tractors as well as the 578, 583R, and 57H pipelayers. The muffler is part of the engine exhaust system, reducing noise and directing exhaust gases away from the operator and engine compartment. Compatible Models Fits Caterpillar Track Type Tractors: D8N, D8R, D8R