A manual gearbox (MT) is reliable, but it is not immune from failures. If you notice unusual sounds, tapping, roaring, reduced traction, slipping, gearing failures or oil leakage, your MT needs diagnostics. The MT diagnostics involves the check of the oil level and its condition, the gearbox’s body, the degree of wear of the bearings, the condition of the shafts, gears, gear-selector mechanisms, the condition of the synchronizer, the wear of the sealing elements and working surfaces. Based on the results of diagnostics, the unit can be repaired or replaced.