Pistons and conrods – assembly overview and fastening

• 1 Bolts
  • Renew after removal
  • Oil threads and contact surface
  • 30 Nm + 90°
• 2 Conrod bearing cap
  • The conrod bearing cap only fits in one position and only on the appropriate conrod due to the breaking procedure (cracking) separating the cap from the conrod.
  • Mark allocation to cylinder and conrod in colour
    • B-.
  • Installation position: Lug
    • A- on conrod bearing cap faces towards pul‐

ley end

• 3 Bearing bushes
  • Fitting position ⇒ 4.1 Assembly overview - pistons and conrods
  • Renew worn bearing shells
  • Ensure firm seating
• 4 Connecting rod
  • With industrially cracked conrod bearing cap
  • Renew as set only.
  • Mark allocation to cylinder and conrod bearing cap in colour -B-.
  • Measuring radial clearance ⇒ 4.6 Checking radial clearance of conrods
  • Separating new conrod ⇒ 4.2 Separating new conrod.
  • Installation position: Lug -A- on conrod bearing cap faces towards pulley end
• 5 Retaining ring
  • Qty. 2
  • Renew after removal
• 6 Piston pin
  • Removing and installing ⇒ 4.3 Removing and installing pistons
• 7 Piston
  • Mark installation position and cylinder number ⇒ 4.1 Assembly overview - pistons and conrods.
  • Removing and installing ⇒ 4.3 Removing and installing pistons
  • Checking piston and cylinder bore ⇒ 4.5 Checking pistons and cylinder bores
• 8 Piston rings
  • Compression rings
  • Measuring ring gap ⇒ 4.5 Checking pistons and cylinder bores
  • Measuring ring-to-groove clearance ⇒ 4.5 Checking pistons and cylinder bores
  • Use commercially available piston ring pliers to remove and install.
  • Installation position: marking “TOP” or side with lettering towards piston crown
  • Offset gaps by 120°
• 9 Piston ring
  • Oil scraper ring
  • Measuring ring gap ⇒ 4.5 Checking pistons and cylinder bores
  • Measuring ring-to-groove clearance ⇒ 4.5 Checking pistons and cylinder bores
  • Use piston ring pliers to remove and install.
  • Installation position: marking “TOP” or side with lettering towards piston crown
  • Offset gap 120° relative to lower compression ring

Installation position and allocation of piston to cylinder

• If worn pistons are to be reinstalled, mark their allocation to the cylinder on the piston crown. Use paint for marking.

• Arrow on piston crown points to pulley end -arrow-.

Bearing shells - installation position

• Centre bearing shells on conrod and on conrod bearing cap.

• Distance -a- = distance -a-.

Oil spray jet and pressure relief valve

• 1 Bolt with pressure relief valve, 27 Nm
• 2 Oil spray jet (for cooling of pistons)

• Installation position: align leading edge of oil spray jet arrow with machined surface of cylinder block.

Risk of damage to oil spray jets caused by deformation.

• Do not bend oil spray jets.