Diesel Engine Service

   What parts of the Diesel engine require servicing?
the reciprocating and rotating parts of the Diesel engine requiring servicing are:
      1. Pistons.
      2. Connecting rods.
      3. Crankshafts.
      4. Valves.
      5. Valve gear.
      6. Camshafts.

   How can the cylinder walls reconditioned?
      Preliminary to servicing pistons, the cylinder walls should be placed in proper condition. Cylinders which are not badly scored but need cleaning up to bring them within satisfactory working limits may be reconditioned with hone.

 How can the cylinder bore be reconditioned?
      The bored should be checked with an accurate gauge to determine whether or not it
 is either out of round or tapered.
      A used cylinder bore should have an out-of-round measurement of not more than .0005 in. and not more than .0005-in. taper.
Maximum allowable out-of-round measurement is .004 in. and .030 in. for maximum taper.

   What should be done if the cylinder walls are badly scored, tapered, or out of round?

     They should first be bored with a reliable boring tool and then polished with a hone.
when reconditioning cylinders, the crankshaft and main bearing should be covered to prevent cutting and abrasives getting in bearings. After completing the reconditioning, the engine should be thoroughly cleaned before fitting the pistons.

   How is correct fit of piston determined?

      Correct piston fit is determined by placing a long 1/2-in. wide feeler gauge along the side of the piston at 90 degree around the piston from the piston pin, and inserting the piston and feeler gauge into the cylinder bored.
      Atypical piston should push through the cylinder with light pressure when a .002-in. feeler gauge is used and should lock with .003-in. feeler gauge.
      permanently mark the  piston for the cylinder to which it has been fitted and procced to hone the cylinder and fit the remaining pistons.

   What factors should be considered in fitting a aluminum-alloy pistons?
     Aluminum-alloy pistons will contract at low temperature, especially after the engine remains idle for a period of time and the oil film drains from between the moving parts. A perceptible sound of pistons and valve mechanism when starting a cold engine is, therefore, normal and should cause no harm or damage and does not indicate improper piston fitting, provided the sound is not heard after the engine has reached normal engine operating temperature.