Nissan Maxima QX

since 1993 release

Repair and operation of the car


Nissan Maxima QX
+ Cars of the Nissan Maxima brand
+ Maintenance instruction
+ Settings and routine maintenance
- Engine
   + SOHC engines
   + DOHC engines
   - General capital repairs of the engine
      General information
      Check of pressure of oil
      Check of compression pressure in cylinders
      Diagnostics of a condition of the engine with use of the vacuum gage
      Alternative versions of schemes of recovery repair of the engine
      Removal of the power unit from the car - preparation and precautionary measures
      Removal and installation of the engine
      Order of dismantling of the engine by preparation it to capital repairs
      Dismantling of a head of cylinders
      Cleaning and check of a condition of a head of cylinders
      Service of valves
      Assembly of a head of cylinders
      Removal of conrod and piston assemblies
      Removal of a bent shaft
      Cleaning of the block of the engine
      Check of a condition of the block
      Honingovaniye of mirrors of cylinders
      Check of a condition of components of conrod and piston group
      Check of a condition of a bent shaft
      Check of a state and selection of inserts of radical and conrod bearings of a bent shaft
      Check of a condition of camshafts, pushers of valves and bearings
      Engine assembly order
      Installation of piston rings
      Installation of a bent shaft and check of working gaps of radical bearings
      Installation of a back epiploon of a bent shaft
      Installation of conrod and piston assemblies and check of size of working gaps in conrod bearings of a bent shaft
      Trial start and running in of the engine after capital repairs
+ Cooling systems, heating
+ Power supply system and release
+ Engine electric equipment
+ Control systems of the engine
+ Transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment

Removal of conrod and piston assemblies

Before starting extraction from the engine of conrod and piston assemblies, it is necessary to remove heads of cylinders, the pallet of a case and a maslozaborny tube (see the Part SOHC Engines or DOHC Engines of the present Chapter).


 PERFORMANCE ORDER

1. By means of a special vertical drill completely remove traces of step wear from the top part of cylinders - act according to the instructions of the manufacturer attached to a vertical drill. The step is formed on piston stroke border, approximately in 6.4 mm under the top cut of the cylinder due to mechanical production of metal and a nagaroobrazovaniye, it is possible to determine its existence to the touch by a finger nail. Attempts of extraction of conrod and piston groups without removal of step development are fraught with damage of pistons.

2. Having finished preparation of cylinders, turn the engine upside down so that the bent shaft appeared from above.

3. Before removing rods from a bent shaft, estimate the size of an axial side play of their landing on necks of the last. Densely enter an edge(s) of the measuring probe into a gap between a sidewall of the lower head of a rod and a cheek of a crank, having completely chosen a rod side play on a shaft neck. Total thickness of the picked-up probe edges will also equal to the size of an axial side play of a rod. Compare result of the taken measurement to requirements of Specifications. If the size of an axial side play exceeds extreme admissible value, this rod is subject to replacement. The axial side play of a new rod, or old on new to a shaft, can appear less than the lower admissible limit, in this case the rod can be pierced - consult with specialists of car service. Serially check all remained rods.

4. Make sure available on the lower heads of rods and their covers of identification tags of belonging to the cylinder, in case of need put tags independently by means of a small center punch.
5. In stages (on 1/2 turns for approach) weaken nuts of fastening of covers of the lower heads of rods so that the possibility of their otvorachivaniye manually appeared. Uncover the first rod together with the bearing insert placed in it, try not to drop the last.

6. For protection of a neck of a shaft and a mirror of the cylinder pull couple of pieces of the hose suitable by the size on bolts of fastening of the lower head of a rod.

7. Take a bearing insert from a rod head, then, having rested the wooden handle of the hammer against a bearing bed in the lower head, push out conrod and piston assembly from the block at the top of the cylinder. At emergence of resistance immediately stop extraction of assembly and make sure of completeness of removal of step wear in the top part of the cylinder.
8. Working in a similar manner, take the remained conrod and piston assemblies from the engine.

Installation of the rod which is subject to extraction coaxially to the cylinder is made by the corresponding provorachivaniye of a bent shaft, - start extraction only after the rod is located strictly parallel to a cylinder axis!

9. In order to avoid casual mechanical damage of bearings and loss of components, establish into place inserts and fix covers of bearings on the lower heads of the rods, having by hand tightened nuts.
10. Do not remove pistons from rods (for more details see the Section Check of a Condition of Components of Conrod and Piston Group).