Government agencies have announced recalls of hydraulic floor roller jacks and three types of canned beef.

The National Highway Traffic Safety Administration said yesterday that three firms are recalling about 100,000 of the jacks. Their top leveling mechanism can tip over because of a design flaw, throwing the car off, an NHTSA official said. Six injuries have been reported to the agency.

Involved are Hollywood Accessories Model 646, G. I. Joes Models J-204 and W-1629, and Midland International Corp. Medallion Model 62-219.

The jacks, used both by do-it-yourselfers and service stations, have an all-steel, wide-bodied chasis with steel caster in the front and rear, and a single-arm leveling mechanism on the right side. They are rated at 3,000 pounds.

NHTSA believes that the majority of such jacks, being sold in the United States for between $49 and $100, are manufactured in Taiwan by two or three firms. In order to widen its investigation, the agency is asking owners of the recalled jacks or owners of any similar jacks who have experienced failures to contact the NHTSA by writing to 400 Seventh St. SW, Washington, D.C., 20590, or by phoning a toll-free number: 800 - 424-9398.

Hollywood Accessories will repair its jacks at no cost, and owners should contact the Customer Service Department, Hollywood Accessories, 19914 S. Via Baron, Compton, Calif., 90220.

G. I. Joes reports that none of its jacks were sold to consumers and it is recalling the jacks in question from dealers for scrapping.

Midland International reports that it will replace the support crutch on its jacks and owners were asked to contact the firm's Medallion Division, 1900 Johnson Drive at State Line Road, Shawnee Mission, Kan., 66205.

The Agriculture Department is recalling cans of beef, corned beef or beef with gravy containing the code number 1964 as a precaution.

Some cans of beef, produced by a single plant in Argentina, were found to be underprocessed in a Puerto Rican warehouse and prevented from entering the United States.

Official said Monday that the packer, Casasa, S.A. Dolores of Buenos Aires, agreed to the recall voluntarily as a precaution even though all the firm's products which reached the U.S. market passed inspection. The recall was issued to guard against the possibility that some underprocessed cans escape detection.

Spokesmen said the products, mostly canned corned beef, are marketed under a wide variety of brand names, but all can be identified by the code number 1964 embossed on the cans and, in some cases, printed on labels.

The canned beef is distributed nationwide by 84 firms under a wide variety of brand names for retail sale and to food plants for reprocessing into foods such as corned beef hash.

Spokesmen said consumers are urged to return any cans with the code number 1964 to the stores where they were purchased and should not even taste beef from the cans.

Officials said no further shipments from the plant will be allowed in the United States until it has taken corrective measures.