The utility model relates to a clutch structure, in particular to an auxiliary mounting structure for a clutch, especially for a braking clutch of a bulldozer. The structure comprises a casing mounted in a steering brake assembly, wherein a piston is mounted in the casing, and a spring is arranged between the piston and the casing; a braking outer hub is fixed on the casing and has a braking inner hub at the inner ring of the braking outer hub; a ring groove is formed between the braking inner hub and the braking outer hub; a friction plate and an outer teeth plate are arranged in the ring groove; the friction plate is fixed on the piston; the outer teeth plate is connected with the braking outer hub; a plurality of threaded holes are formed in the casing; threaded holes identical to the threaded holes on the casing are formed in the corresponding positions of the piston. The structure provided by the utility model reduces the phenomenon that the spring is misplaced or stressed unevenly, hence improves the mounting efficiency, and meanwhile reduces the possibility of the misplacement between the marking holes on the piston and the threaded holes on the braking inner hub, and hence improves the mounting efficiency.