Blow the parts with a stream of compressed air and wipe them carefully. Blow the bearings especially carefully, directing the stream of compressed air so that the rings do not rotate quickly.
Crankcase and covers. There should be no cracks on the crankcase, and no wear or damage on the surface of the bores for bearings and seals.
The mating surfaces with the clutch housing, rear and lower covers must be free of damage to prevent oil leakage. Smooth out minor damage with a file. If the parts are too damaged or worn, replace them with new ones.
Check the condition of the front cover and make sure that the input shaft does not touch it when rotating. If misalignment of the shaft and cover is detected, replace the damaged parts.
Check if the oil drain hole in the cap is clogged (shown by the arrow in Figure 3-9). Clean the drain plug.
Oil seals. Check the oil seals and make sure there is no damage, unacceptable wear or unevenness on the working edges. The wear of the working edges of the oil seals in width is allowed to be no more than 1 mm. If even a minor defect is detected, replace the oil seals with new ones.
Shafts. No damage or excessive wear is allowed on the working surfaces and on the splines of the secondary shaft. There should be no roughness or scoring on the rolling surfaces of the needles at the front end of the shaft.
Check the condition of the rolling surface of the needles in the bore of the primary shaft.
Inspect the intermediate shaft for chipping or excessive tooth wear.
The surface of the reverse gear pinion axle must be completely smooth, without any signs of seizing. The mounting clearance between the axle and the intermediate reverse gear bushing is 0.056-0.09 mm, the maximum permissible clearance is 0.15 mm. Check the clearance by measuring the axle diameter and the pinion bushing hole. The axle diameter of new parts is 19.079-19.094 mm, and the inner diameter of the pressed bushing is 20.05-20.07 mm.
If there is damage or deformation, replace the shafts with new ones.
Gears. There should be no damage or excessive wear of the teeth on the gears. Pay special attention to the condition of the ends of the teeth on the synchronizer rings.
The contact patch of the gear teeth engagement must be located over the entire surface, which must be smooth and without signs of wear. Check the clearance in the engagement between the gear teeth, the installation value of which must be 0.10 mm; wear limit gap - 0.20 mm.
The mounting clearance between the bushings and the gears of the 1st and 5th gears and between the secondary shaft and the gears of the 2nd and 3rd gears should be 0.05-0.10 mm; wear limit gap - 0.15 mm.
If wear exceeds permissible limits, replace the gears with new ones.
Bearings. Ball or roller bearings must be in perfect condition. Their radial clearance must not exceed 0.05 mm.
Pressing the inner ring to the outer ring with your fingers, rotate one of them in both directions, the rolling should be smooth. No damage is allowed on the surface of the balls or rollers and the raceways of the rings. Replace damaged bearings with new ones. When replacing the front bearing of the primary shaft, use a special puller (see figure 2-11); in this case, the flywheel does not need to be removed.
Rods and forks. Deformation of the gear shift forks is not allowed. The rods must slide freely without significant clearance in the crankcase holes.
Check the condition of the rod locking crackers, springs and locking balls. Replace parts that show signs of seizing or wear with new ones.
Hubs, couplings and synchronizer locking rings. Check for signs of seizing on the coupling hubs, especially on their sliding surfaces. Pay particular attention to the condition of the coupling tooth ends.
Excessive wear of the surface of the locking rings is not allowed. They must be replaced if their end is resting against the synchronizer clutch. Any irregularities that prevent free sliding should be removed with a velvet file. Replace parts that are worn beyond the permissible limits with new ones. Pay special attention to the condition of the short teeth on the synchronizer hubs: replace parts with crumpled ribs on the ends with new ones.