They actually participated in one of the lesser known operations, the Manchurian Strategic Offensive, in the form of a large portion of the Cavalry-Mechanized Group, perhaps the ultimate fulfillment of the Mongolian Horse-cavalry trope. Attacking over a 250km frontage, they advanced 420-550km in 10 days.

Here's a handy graphic, label of Mongolans and arrows added by yours truly.

Source: Leavenworth Papers No.7: August Storm, David M. Glantz, Levenworth, KS, Feb. 1983.