Fault factor for bolts:

 

The torque is too large and uneven when installed. Because there is no strict torque wrench in the installation, detail-tightening torque is not too familiar, think the tighter the better; Tighten bolts connecting rod with a long rod tension, tightening torque is too big, more than the bolt material yield limit, the connecting rod bolt bending deformation, make it under the effect of impact load due to excessive elongation of the craze. It should be emphasized that it is necessary to tighten the rod bolts according to the specification. Do not assume that the tighter, the stronger the better.

 

The connecting rod of diesel engine is divided into several grades, and the connecting rod of different grades should not be changed in the repair. If because of careless in the repair is not careful will mess up connecting rod cover, wrong, can form on the surface of the big end contact cooperation is not tight, will form the connecting rod in the engine cover is loose and the connecting rod bolt crack. The main rod of WD615 series diesel engine is inclined notch, and the Angle is 45 & deg. The connecting rod cover and connecting rod are selected 60 & deg; The zigzag positioning structure is characterized by close-knit, precise positioning, solid and compact structure. If the repair will head to confuse, wrong, is bound to form LianXiMian sawtooth position owe good, very easy to form the lid of the engine connecting rod in a work loose, and the connecting rod bolt crack.

 

In the operation, the diesel engine presents the problem of the flying car or the piston is burned in the cylinder, and the connecting rod is broken. If the engine is in the application of the problem of the flying car, the engine to do a full view, the best replacement connecting rod bolts; If the single cylinder in operation presents a severe cylinder, the connecting rod should also be replaced when replacing the cylinder piston component.

 

The problem of raw material, processing defects and heat treatment technology can also cause the connecting rod bolts to crack in the engine operation.