2022.3-0000010 OM As the rear wheel skidding exceeds the preset value, the shaft 6 speed decreases to such extent that the drum 3 turns in an opposite direction and the spring 5 returns the half-clutch 4 into its initial position. The half-clutch displaces the pusher 12 with its tapered part, the switch 13 closes the electrical circuit of the hydraulic valve group 11 electromagnet, oil is supplied to the clutch booster under pressure, thus moving the piston 2. Hereby the disk pack gets compressed, locking the gear 1 and the drum 3 and ensuring torque transfer. As the FDA is positively engaged, oil is supplied to the clutch booster irrespective of the rear wheel skidding. As the FDA is disengaged the valve group overlaps the charging line, and oil goes from the clutch booster for drain. For checking pressure in the drive clutch booster there is a testing hole, shut with a plug 14. The switch 13 and the electro-hydraulic valve group 11 are guarded with a housing 10. Rules for FDA drive control are provided in section 2 “Controls and instruments”. 3.11.4.2 Adjustment of FDA drive automatic switch
1 – drum; 2 – half-clutch; 3 – pusher; 4 – shim; 5 – switch; 6 – cover. Figure 3.11.6 – Adjustment of FDA drive automatic switch
The adjustment of the switch 5 (figure 3.11.6) shall be carried out after the hydraulic clutch has been assembled and the cover 6 has been mounted on the transmission in the following order: - turn the drum 1 and set put it into position “I”, when the jaws of the half-clutch 2 and the drum 1 are fully closed, the pusher 3 is projected into the extreme position; - mount the initial number of the adjusting shims 4 (five or six pieces) under the end surface of the switch 5; - removing one adjusting shim 4, achieve the switch position, when its contacts are closed; - put the half-clutch 2 into position “II”, when the jaws of the half-clutch 2 and the drum 1 are fully opened, the pusher 3 is recessed to the extreme position; - check opening of the switch 5 contacts in position “II”. The switch is considered correctly adjusted if its contacts are closed in position “I” and opened in position “II”. Check per the pilot lamp. It is possible to check per the annunciator on the dashboard, with the FDA drive control button in the upper position. ATTENTION: IN POSITION “I” THE DIMENSION “A” FROM THE PUSHER 3 END SURFACE (FIGURE 3.11.6) TO THE SWITCH 5 END SURFACE BEING BELOW 11,5 MM IS NOT PREMITTED! VIOLATION OF THIS REQUIREMENT MAY RESULT IN SWITCH BREAKDOWN! 124
