4.4.3. Check of a beam of the back bridge

Carefully check technical condition of a beam, especially at car repairs, crashed. The deformed beam can be the reason of noise of the back bridge and the accelerated wear of tires.
Deformation of a beam of the bridge is checked both in horizontal, and in vertical the planes.
Having attached a flange of A.70172 to each end of a beam, establish a beam by flanges on the identical prisms located on a testing plate not less than 1600 mm long so that the case prileganiye surface to a beam was in the vertical plane.

Fig. 4-54. Check of vertical deformations of a beam of the back bridge by means of a square on an external surface of a flange of A.70172

Fig. 4-55. Check of twisting of a beam of the back bridge by means of a square on a side surface of a flange of A.70172

Check deformation of a beam, putting a square to external (fig. 4-54) and side (fig. 4-55) to surfaces of a flange of A.70172; if the beam is not deformed, the square will densely adjoin.
The size of deformation is checked the probe. If the probe of 0,2 mm passes on any flange, it is necessary to correct a beam.

Fig. 4-56. Check of perpendicularity of a surface of fastening of a reducer

Square (fig. 4-56) check perpendicularity of a surface of fastening of a reducer of rather basic surface of a flange of A.70172. The probe of 0,2 mm should not pass.

Fig. 4-57. Check of horizontal deformations of a beam of the back bridge by means of a square on an external surface of a flange of A.70172

Turn a bridge beam on 90 ° and establish it on prisms. The square attached to an external surface of a flange (fig. 4-57) has to adjoin densely, otherwise check deformation size the probe. The probe of 0,2 mm should not pass.
At the deformation exceeding the specified size correct a beam, adhering to the instructions given below.
After performance of all changes carefully wash out a beam, clear a magnetic stopper, establish into place and check:
— quality of welded seams and tightness of a beam;
— purity in a beam (lack of agnails, shaving and the remains of oil) and purity of a sapun of a beam.
After that paint a beam outside for protection from corrosion.