Abstract The viscosity coefficient obtained in a previous paper of this series is calculated as a function of density by developing the N-particle collision operator into a dynamic cluster expansion. The excess transport coefficient Δη is given in an exponential form, Δν=ν 0 exp ∑ l=1 ∞ β ln l −1 where η 0 is the two-body Chapman-Enskog result for the transport coefficient, n is the density, and β l is a density-independent quantity consisting of connected cluster contributions of ( l + 2) particles. Therefore, the leading term β 1 consists of connected three-body cluster contributions. The excess shear viscosity coefficient is calculated for a monatomic hard-sphere fluid by computing β l up to the three-body contributions and the result is compared with the molecular dynamics result by Ashurst and Hoover and also with the experimental data on Ar at 75°C. In spite of the crudity of the potential model used and the approximations made the agreement is good. The result can be improved if l-body clusters ( l ⩾ 4) are included in the calculation. The thermal conductivity coefficient can be obtained in a similar form by using exactly the same procedure used for the viscosity coefficient.