Transfer case (A540N) — general information [Toyota Carina T190]

4WD vehicles have permanent all-wheel drive, the so-called "Full time 4WD", with automatic interaxle differential lock. Depending on the configuration, locking can be done in two ways:

1) With mechanical locking system of the center differential (C. DIF. AUTO). When you press a button on the instrument panel, the hydraulic drive located on the transfer case locks the interaxle differential on command from the electronic control unit. This results in the necessary distribution of torque to the front and rear axles, which significantly improves cross-country ability.

2) With automatic center differential locking system (viscous coupling). This system does not require driver intervention, but cars equipped with this system have worse cross-country ability compared to cars with the "C. DIF. AUTO" system. This is due to the fact that the viscous clutch does not provide 100% locking and the clutch is activated with a slight time delay.



[The official source is on the portal: toyotaman]