Page 7 - E BOOK ENGINE MECHANICAL M2

1. TECHNICAL FEATURES OF 4B1 ENGINE

(5) Crankshaft Bearings, Thrust Bearings

Fig. 1-6

The upper crankshaft bearing half has the oil groove. The lower half is not designed with an oil
groove. Each crankshaft bearing is provided with a backing plate. The bearing portion is made of an
aluminum alloy and its backing plate is made of ordinary steel. A thrust bearing, which sustains the
load in the thrust direction, is provided at each end of the No. 3 bearing.

(6) Timing Chain Train

Fig. 1-7

The two camshafts are driven by the timing chain via the camshaft sprockets.
The timing chain is a silent / endless type, consisting of 180 links. It is installed around the Variable
Valve Timing (V.V.T.) sprockets and the crankshaft sprocket.
Two (blue) marks and One (orange) mark are painted on three of the timing chain link plates to
properly time the camshafts with the crankshaft.

1 - 4 Pub. No. PTAE1225