20.1 On 4-cylinder engines, install an oil separator with a strainer before assembly
2. Unscrew the cap bolts, remove the caps and lay them out in the order they were installed. Remove the old main bearing shells from the caps and cylinder block and wipe the caps and beds clean.
3. Clean the outer surface of the new main bearings with oil grooves and insert them into the cylinder block beds. Insert the corresponding mating bearings into the covers. Make sure that the protrusion on the bearing coincides with the groove on the block or cover. In addition, the hole in the oil channel in the cylinder block bed must be aligned with the hole in the bearing (photo).
20.3 Cylinder block liners
Attention! Do not install the insert by hand, by hammering, or by scratching it during installation.
Attention! Do not lubricate the insert at this stage.
4. On V6 engines, the flanged insert is installed in the rear cover and bed of the cylinder block; on 4-cylinder engines, such an insert is installed in the middle cover.
5. Install the crankshaft and measure the clearances in the main bearings. To do this, place a piece of calibration wire on each main journal of the crankshaft parallel to its axis (photo). Clean the surfaces of the bearings in the covers, install the covers and tighten the bolts in three steps with the specified torque in the specified sequence (photo). Unscrew the bolts and carefully lift the covers, compare the thickness of each of the crushed wires with the scale on the package and determine the gap size (photo).
20.5a Sections of calibration wire for measuring clearances in main bearings
20.5b Sequence of tightening main bearing cap bolts on 4-cylinder engines
20.5v Tightening Sequence for Cap Bolts on V6 Engines
20.5g Determining the clearance in the main bearings
(The original is available on the web page: «NISSANBOOK.RU»)
6. If the clearance is not within the norm, the reason may be the incorrect selection of the size group of liners. Make sure that there is no dirt or oil between the bearings and the cover surfaces during measurements. If the width of the crushed wire at the ends is very different, then the crankshaft main journal is taper.
7. Remove any remaining wire from the journals and remove the crankshaft.
8. Lubricate the crankshaft journals and install them in the cylinder block. Install the covers in their original places so that the arrows point toward the front of the engine. On 4-cylinder engines, the rear cover is installed with sealant (photo).
20.8 Installing the rear cover on 4-cylinder engines
1. Cylinder block; 2. Back cover; 3. Places of sealant application
9. Tighten the bolts in three stages to the specified torque.
10. Install the pilot bearing into the crankshaft (for cars with manual transmission).
11. Check the freedom of rotation of the crankshaft.
12. Check the crankshaft axial play (see above).
13. On 4-cylinder engines, install the side seals (photo).
20.13 Installing the side seal on 4-cylinder engines