Their poor bonding could reduce the effectiveness of airbags in case of an accident and affect the vehicles' roof.
All the recalled vehicles were made between Jan 9 and July 9 last year.
Ford did not disclose if they were made locally or imported.
Ford Ranger trucks started to be assembled in Vietnam last July, though the XLS version continues to be imported.
They have been the top selling trucks in Vietnam for years despite being one of the most expensive in the segment.
They cost VND628-937 million (US$26,850-40,000).
Ford sold 9,697 units in the first six months, down 15 percent year-on-year, according to the Vietnam Automobile Manufacturers Association.