Checking the connecting rods
1 - Connecting rod; 2 - Connecting rod cover; 3 - Bushing; 4 - Guide grooves; 5 - Connecting rod bolt; 6 - Balancing weights; 7 - Identification field (turbocharged models); 8 - Grooves for installing liners; 9 - Oil channel (turbocharged models); 10 - Oil channel (non-turbocharged models); 11 - Identification field (non-turbocharged models); b - Width of the upper connecting rod head; B - Width of the lower connecting rod head; d - Inner diameter of the connecting rod upper head bushing; d1 - Outer diameter of the connecting rod upper head bushing; D1 - Connecting rod lower head bore diameter; L - distance between the centers of the holes of the connecting rod heads
1. Remove the pistons (see section Removal and installation pistons).
2. Check the connecting rods for discoloration, warped holes and grooves. If these damages are found, the connecting rods must be replaced.
3. Check the connecting rod cap mounting bolts.
Text republished from the website [mercedesman]
4. Measure the connecting rod bore diameter. If the diameter is greater than the maximum allowable, grind the contact surface of the cover by no more than 0.02 mm.
5. Check the inner diameter of the connecting rod bushing.
6. Installation is carried out in the reverse order of removal. The dimensions of the connecting rods are given in Specifications.