Reliable system-level simulation tools capable of modelling and predicting the physical interactions between components are of special interest in the analysis of mecha(tro)nic drivetrains. In such drivetrains the flexibilities of shafts and bearings alter the gear alignment conditions, thereby requiring gear contact models that are capable of capturing the associated misalignment effects. In this contribution, an efficient yet accurate model for misaligned helical gear contact analysis is derived by lumping a distributed-parameter model that was recently developed by the authors and validated numerically by comparison with finite element simulations. The transformation into a lumped-parameter model relies on a computationally efficient linearization approach that can be generalized to other gear contact models. The developed model is numerically validated on the component-level by comparison with finite element simulations of a helical gear pair considering various misalignments. The twisting rotation is shown to be the most influential misalignment, significantly altering the transmission error and thereby dynamic performance of the gear pair, and is well-captured by the developed lumped-parameter model. In order to demonstrate the model’s capabilities and computational efficiency in a system-level simulation, the model is implemented in a port-based multi-physical simulation environment, where it is used to simulate a two-stage helical automotive transaxle.