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 a bent shaft

Removal of a bent shaft is possible only from the engine taken from the car. It is meant that a flywheel / a driving disk, a pulley of a bent shaft, a gas-distributing belt / chains with gear wheels / asterisks, the case pallet, a maslozabornik, the oil pump and conrod and piston assemblies are already dismantled (see the Part SOHC Engines or DOHC Engines of the present Chapter). Before removal of a bent shaft it is also necessary to otboltit and separate from the block of cylinders the holder of a back epiploon.


 PERFORMANCE ORDER

1. Before starting extraction of a bent shaft from the engine, measure the size of its axial side play. Fix the DTI measuring instrument on the block to coaxially bent shaft, having rested its plunger against a cheek of one of cranks or against a shaft pin end face.

2. Push a bent shaft against the stop back and nullify the device indicator. Now push a shaft in an opposite direction and consider the indication of the measuring instrument. The size of a free wheeling of a shaft in the longitudinal direction is also its axial side play. Compare result of measurement to requirements of Specifications. If the side play exceeds the maximum admissible value, check persistent surfaces of a shaft for existence of signs of excessive wear. In the absence of obvious signs of wear, installation of new persistent washers usually helps to correct a situation.

3. In the absence of near at hand dial measuring instrument it is possible to use the ordinary probe of lezviyny type. Accurately shift a shaft against the stop forward on the engine, then determine the size of the formed gap between a cheek of a crank and a forward wall of the back (persistent) radical bearing, having densely put in it the corresponding thickness a probe edge(s).

4. In stages (on 1/4 turns for approach) in strictly certain order, the return to an order of their tightening (see the Section Installation of a Bent Shaft and Check of Working Gaps of Radical Bearings), weaken bolts of fastening of covers of radical bearings so that the possibility of their reversing manually appeared. Covers of radical bearings are usually equipped with cast tags in the form of the arrows, at the correct installation specifying towards the GRM drive. In case of need put similar marking independently by means of a center punch.

On SOHC engines it is enough to mark the direction of landing of covers only of forward and back bearings, - other covers represent monolithic assembly.

5. Carefully tap covers of bearings the hammer with soft brisk and remove them from the engine block. In case of need use bolts as levers. Track that at dismantle of covers were not lost the inserts of radical bearings enclosed in them.
6. Carefully take a bent shaft from the engine (in view of relevancy of weight of assembly it will be reasonable to secure with the help of the assistant). Track that inserts of radical bearings remained in the beds in the block and covers. Establish covers on the regular places on the block, and by hand tighten fixing bolts.

7. On DOHC engines it is necessary to estimate degree of a pulling of bolts of fastening of covers of radical bearings. If the difference between diameters of a carving part of a bolt measured on the sites noted on an illustration exceeds 0.11 mm, the bolt is subject to replacement.

Strictly speaking, it makes sense to get a replaceable set of fixing bolts at once and to use it at assembly.