Z31 Crank Pulley Differences
The Z31 came with four different Crank pulleys. Non turbo from 84 to 86 had all V-belts. The turbo models used a ribbed belt for the alternator and v belts for the other accessories. Early 1987 models switched to to all ribbed micro v belts. The later models 4/87-89 used a longer snout on the crank shaft, therefore using a new pulley that is a 13.6 mm thicker.
84-87 Non turbo Crank Pulley
The 84-86 non turbo models have all V belts.
84-86 Turbo Crank Pulley
The 84-86 turbo models have 2 V belts and 1 ribbed micro V belt.
pre 4/87 Crank pulley
The pre 4/87 crank pulley uses all ribbed micro V belts like the W-series but does not have the same offset.
post 4/87-89 W series Crank pulley
The crankshaft front tip was lengthened by 18.7 mm (0.736) in. See illustration (*1). The crankshaft pulley width was increased by 13.6 mm (0.535 in.) as shown (*2). The pulley bolt was changed from M12 to M14, and the washer inner and outer diameters were increased. (See illustration.)
