Dart Drug Corp., which has caused a retail revolution in book-selling here through its discount Crown Books division, is entering the automotive parts retail sector with hopes of similar success.

Without fanfare, Dart opened three units in recent days called TRAK Auto, each featuring some 16,000 domestic and imported auto parts, supplies or accessories.

The merchandise carries discounts of at least 35 percent from manufacturers' suggested retail prices, and some of the discounts are much steeper.

Dart's quiet entry into auto parts retailing also coincided with the decision of a Beneficial Corp. unit, Western Auto Supply Co., to close four or five company-owned stores in the Washington area -- a move that doesn't affect half a dozen independently owned Western Auto outlets here.

The initial Dart TRAK Auto stores are located in shopping centers, adjacent to Dart Drug units, at 2901 Gallows Rd., Merrifield; 1456 Jefferson Davis Highway, Woodbridge; and 7756 Marlboro Pike, District Heights.

Ben Kovalsky, Dart senior vice President and TRAK Auto chairman, said yesterday that his firm plans to open 3 other stores here within 90 days. Ultimately, 18 to 24 stores are planned in the metropolitan area, he added.

Kovalsky said in an interview that Dart's move into the auto parts business has been in the planning stages for five years but that a final decision to move ahead with the project was made only last January.

In many respects, TRAK Auto stores will build upon the discount retail record of Crown Books, which Dart opened late in 1977. Crown discounts best-selling books by 35 percent and offers other discounts on remaining books. TRAK officials say they have identified 13 major categories of consumer purchases in the auto parts area, accounting for about half of each store's merchandise, and will offer 35 percent discounts on these products.

Among bran-name parts on TRAK Auto shelves are items manufactured by AC-Delco, Purolator, Champion, Bendix, Motorcraft, Mopar and TRW.

"The concept of merchandise mix and discount strategy has not been seen anywhere else," Kovalsky claimed yesterday, although some retailers in California have a similar concept. Dart is counting on a high volume of sales to generate operating profits, as it does with Crown Books.

In the retailing business generally, discount operations recently have become among the most profitable. Large volumes of merchandise are being sold quickly, keeping inventory backlogs at a minimum at a time when inflationary pressures have forced some consumers to consider do-it-yourself projects. Such businesses as Hechinger's, the Landover based hardware chain, are in the midst of a boom.