Usage:
776B (6JC),
776C (2TK) Tractors;
777B (4YC),
777C (4XJ) Trucks
Description of Change: A new slip-fit muffler replaces the former flange-type muffler in the muffler group used on these machines. The new muffler eliminates the flange and the possible fatigue around the flange area. A new exhaust pipe (tube assembly) is used in the exhaust piping groups to work with the new slip-fit muffler.
Adaptable To: The chart and Illustration 1 identify the new and former components in the 7C-4013 Muffler Group. A new 111-4368 Tube Assembly replaces the former 8W-5561 Tube Assembly in the 8W-9078 Exhaust Piping Group (used on 776C Tractors) and the 8W-5559 Exhaust Piping Group (used on 777C Trucks). Also added to the exhaust piping groups are two 7K-3215 Boss and two 8T-2501 Bolts to install the new 111-4368 Tube Assembly. The new components are in effect with 776C (2TK79) Tractor and 777C (4XJ425) Truck. The new components are adaptable to all earlier 776B and 776C Tractors and 777B and 777C Trucks.
The former 4W-0532 Muffler Assembly and 8W-5561 Tube Assembly can be modified to work as slip-fit components as shown in the Modification Procedure.
Illustration 1. Location of new components in 7C-4013 Muffler Group.
Modification Procedure
The former 4W-0532 Muffler Assembly and 8W-5561 Tube Assembly can be modified to work as a slip-fit muffler using the following procedure.
1. Cut through outer shell (12) and insulation (13) 51 mm (2.0") back the outer-most end of V-flange surface (14). Do not cut through inner pipe (15). Remove the outer shell (12) and insulation (13) from inner pipe (15). See Illustration 2.
Illustration 2. Dimensions for modifications to 4W-0532 Muffler Assembly. Muffler outer shell (12). Insulation (13). Location of outer-most end of V-flange surface (14). Inner pipe (15).
2. Cut eight to ten slots (16) around muffler inner pipe (15). The dimensions for the slots are 38 × 4.6 mm (1.5 × .18 in) with a 2.3 mm (.09 in) radius.
3. Fabricate an extension (17) made from 3.2 mm (.12 in) thick weldable steel. The fabricated extension (pipe) should be 76 mm (2.9 in) wide with a 219 mm (8.6 in) outside diameter. See Illustration 3.
Illustration 3. Dimensions for fabricated extension. Fabricated Extension (17). 8W-5561 Tube Assembly (18). V-flange (19).
4. Weld fabricated extension (17) to the end of 8W-5561 Tube Assembly (18). V-flange (19) may need to be removed from the 8W-5561 Tube Assembly.
5. Slide the modified muffler and 4W-1814 Clamp over the fabricated extension on the mating tube assembly and clamp in place.
6. Install mounting bracket.