Assembly overview - pistons and conrods

1 -

Bolts

Renew

Oil threads and contact surface

30 N·m + 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 pulley end

3 -	Bearing shells

Installation position → Fig.

Renew worn bearing shells

Ensure secure seating

4 -

Conrod

With industrially cracked conrod bearing cap

Renew as set only.

Mark allocation to cylinder and conrod bearing cap in colour -B-.

Measuring radial clearance → Chapter

Separate new conrod → Fig..

Installation position: Lug -A- on conrod bearing cap faces towards pulley end

5 -

Circlip

Qty. 2

Renew

6 -	Piston pin

Removing and installing → Chapter „Removing and installing pistons“

7 -

Piston

Mark installation position and cylinder number → Fig..

Removing and installing → Chapter

Checking piston and cylinder bore → Chapter

8 -	Piston rings

Compression rings

Measuring ring gap → Fig.

Measuring ring-to-groove clearance → Fig.

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 → Fig.

Measuring ring-to-groove clearance → Fig.

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

Bearing shells - installation position Centre bearing shells on conrod and on conrod bearing cap. Dimension -a- = 2.5 mm.

Separating new conrods On new conrods it is possible that the breaking point is not fully separated. When the conrod bearing cap cannot be removed by hand, proceed as follows: To avoid damage, gently clamp conrod in a vice with protection jaws, as shown in illustration. Clamp conrod below dashed line. Unscrew bolts -arrows- around 5 turns.

Using a plastic hammer, carefully knock against conrod bearing cap -arrow- until it is loose.