A draft force sensing system (30) for an agricultural tractor has left and right draft bars (32, 34) and a sensing unit (52). The sensing unit (52) comprises a housing (56). Laterally spaced apart left and right pivot pins (90, 92) are mounted in the housing (56). A left sensing arm (94) is pivotally mounted on the left pivot pin (90), the left sensing arm (94) having a shorter arm portion (104) movable in response to draft force applied to the left draft bar (32) and having a longer arm portion (102). A right sensing arm (96) is pivotally mounted on the right pivot pin (92), the right sensing arm (96) having an shorter arm portion (108) movable in response to draft force applied to the right draft bar (34) and having a longer arm portion (106). A resilient member (121) is coupled to the left and right sensing arms (94, 96) and biased to urge the left and right sensing arms (94, 96) towards each other. A stop member (123) is positioned between the left and right sensing arms (94, 96) and engagable with the left and right sensing arms (94, 96) to limit movement of the left and right sensing arms (94, 96) towards each other. A draft force transducer (119) engages the longer arm portions (102, 106) of the left and right sensing arms (94, 96), the draft force transducer (119) generating a draft force signal representing a distance between the longer arm portions (102, 106).