Sunday's move is the last such redeployment expected this month, security sources said.
Syrian air force units left a site in the area of Dhihayr al-Baydar and crossed the border into Syria, an Aljazeera correspondent in Lebanon reported.
To the south of Bekaa province, a Syrian troop carrier was seen leaving a site in Bar al-Yas and heading to the border area of al-Masna.
An estimated 1000 Syrian soldiers have left Lebanon in the past 10 days.
Facing international pressure and Lebanese protests, Syria has promised to withdraw all the military personnel, intelligence agents and equipment it poured into Lebanon early in the country's 1975-1990 civil war.
Damascus has completed the first stage of a two-phase withdrawal plan, pulling back to the eastern Bekaa Valley and withdrawing more than a third of its 14,000 troops completely.
Last week, it pulled troops out of around a dozen positions in the Bekaa. On Sunday, it left its two largest and last anti-aircraft positions, the Lebanese security sources said.
A Syrian-Lebanese military committee is to meet in early April to set a timeline for withdrawing remaining forces.
United Nations Secretary-General Kofi Annan has said he expects Syria to complete the pullout before Lebanese general elections due in May.