Mazda 2006 MX-5 - Crankshaft, Main Bearing Construction [Lf]

MECHANICAL
01–10–4
CRANKSHAFT, MAIN BEARING CONSTRUCTION [LF]
E5U011011301N01
• A five axle-hole, 4 counter weight cast iron
crankshafts have been adopted.
• There is no positioning key where the crankshaft
sprocket and crankshaft pulley are installed. The
crankshaft sprocket must be installed using the
SST with the No.1 cylinder aligned with TDC
position. Tightening pressure on the tightening
bolt is used to secure the crankshaft sprocket and
crankshaft pulley.
• An oil line for supplying oil to each journal is
provided in the crankshaft. Crank pins and fillets
on both sides of the journal are rolled to bear
heavy loads.
• Upper and lower main bearings are made of aluminum alloy and the upper side No.3 journal bearing is
integrated with the thrust bearing. The upper main bearing has oil grooves and oil holes.
• There is no upper and lower bearings' positioning tab for installing the main journal.
• Measure and attach the main bearings (upper and lower) so that they are positioned at the center the main
bearing cap.
• Three kinds of main bearings are available depending on the oil clearance.
Bearings
End Of Sie
E5U110ZT5001
OIL PASSAGE
FILLET ROLL AREA
E5U110ZT5002
MAIN BEARING CAP
MAIN BEARING
SUPPLYING ENGINE OIL
THRUST BEARING
LOWER MAIN BEARING
UPPER MAIN
BEARING
UPPER MAIN BEARING
2 HOLES SUPPLYING
ENGINE OIL
E5U110ZT5011
Bearing size
Bearing thickness (mm {in})
upper lower
STD 2.501—2.522 {0.0985—0.0992} 2.501—2.529 {0.0985—0.0995}
0.25OS 2.623—2.629 {0.1033—0.1035} 2.624—2.630 {0.1034—0.1035}
0.50OS 2.748—2.754 {0.1082—0.1084} 2.749—2.755 {0.1083—0.1084}