Harford County Transmissions Plus is located at 521 Underwood Ln., Bel Air, MD. This business specializes in Auto Repair & Service. Harford County Transmissions Plus is open Mon, Open 24 hours; Tue, Open 24 hours; Wed, Open 24 hours; Thu, Open 24 hours; Fri, Open 24 hours; Sat, Open 24 hours; Sun, Open 24 hours and accepts Cash, Discover, Mastercard, Personal Checks and Visa.