How to change the high and low gears of Sinotruk Haowo?

There are three types of gearbox of Sinotruk Haowo automobile: Fast gearbox, new gearbox of Sinotruk, Qijiang gearbox? .

of course, there are three types of high and low shift:?

one is the low-grade area on the left and the high-grade area on the right. There is a high-low shift switch on the shift handle, with high-grade up and low-grade three-Howe A7 automatic transmission, which is rarely used now.

Of course, it is necessary to step on the clutch before shifting to high and low gear. Although it will be shifted without stepping on the clutch, it is easy to cause the early wear of the gear and synchronizer because the high and low gears of the clutch are not stepped on and the speed of the synchronizer does not match the optimal shift position.