Abstract The renewed platform of the upcoming flagship front-engine, rear-wheel drive (FR) vehicles demands high levels of driving performance, fuel efficiency and noise-vibration performance. The newly developed driveline system must balance these conflicting performance attributes by adopting new technologies. This article focuses on several technologies that were needed in order to meet the demand for noise-vibration performance and fuel efficiency. For noise-vibration performance, this article will focus on propeller shaft low frequency noise (booming noise). This noise level is determined by the propeller shaft’s excitation force and the sensitivity of differential mounting system. In regards to the propeller shaft’s excitation force, the contribution of the axial excitation force was clarified. This excitation force was decreased by adopting a double offset joint (DOJ) as the propeller shaft’s second joint and low stiffness rubber couplings as the first and third joints. The input to the body and its sensitivity were decreased by separating the pitching resonances of body mount bushings and differential mount bushings. For improving fuel efficiency, the differential hypoid gear (D/F) efficiency improvement is described in this article. The hypoid gear specifications, bearings, and oil lubrication system were optimized to improve fuel efficiency. Thus, new D/F efficiency is superior to the previous model in spite of the bigger size, and it achieves its vehicle efficiency development target. A low pinion offset and the low spiral angle of the hypoid gears enable meshing loss reduction. Adoption of ball bearings for the drive pinion axis further enables the reduction in losses compared to conventional taper bearings. Optimization of the carrier lubrication structure and a low oil volume and fill level enable additional reduction in losses and improve the life of the ball bearings by limiting an excessive oil supply to the bearings. Introduction 1-1 Rear Propeller Shaft Function The rear propeller shaft ( Fig.0) is an automobile part that transmits the drive force from the transmission to the rear D/F. The rear propeller shaft is ordinarily composed of 2 to 4 joints, and the number of joints is determined by the propeller shaft’s length. In previous FR passenger vehicles applications, it was typical to apply a 3-joint propeller shaft with rubber couplings as the first and third joints and a cardan joint as the second joint. Figure 0. Rear propeller shaft from the previous model FR passenger vehicles. The cardan joint is composed of a sliding yoke shaft, which has a spline portion so that it can be shortened when it is assembled to the transmission and the rear D/F. After the bolts of both rubber couplings are tightened, the spline portion is also tightened and the length is fixed. The rubber coupling is used to decrease the engine noise and transmission noise. It is especially necessary for luxury class FR passenger vehicles to achieve high levels of noise-vibration performance. The rubber coupling is shown below ( Fig. 1). It is composed of rubber, collars, inner tubes, and wires. The threepronged yoke is alternately attached to the inner tubes of each side of the rubber coupling, and torque from the transmission is transferred mainly by the wires ( Fig.2). The rubber mainly contributes as a damping function, not for torque transmission. Figure1. Rubber coupling and its componentsToyota’s New Driveline for FR Passenger Vehicles 2017-01-1130 Published 03/28/2017 Shinya Takamatsu, Nobuharu Imai, Koji Tsurumura, Seiji Yamashita, and Hiroaki Tashiro Toyota Motor Corporation CITATION: Takamatsu, S., Imai, N., Tsurumura, K., Yamashita, S. et al., "Toyota’s New Driveline for FR Passenger Vehicles," SAE Technical Paper 2017-01-1130, 2017, doi:10.4271/2017-01-1130. Copyright © 2017 SAE InternationalDownloaded from SAE International by University of Minnesota, Wednesday, August 01, 2018Figure2. Torque t