UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported) September 17, 2014

Ally Auto Receivables Trust 2014-2

(Issuing Entity with respect to Securities)

Ally Auto Assets LLC

(Depositor with respect to Securities)

Ally Bank

(Sponsor with respect to Securities)

Registrant’s Telephone Number, including area code: (313) 656-5500

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Item 1.01 and 8.01. Entry into a Material Definitive Agreement and Other Events

Ally Auto Assets LLC (“Ally Auto”) has registered an issuance of $24,098,660,000 in principal amount of asset backed notes on Form S-3 (Registration File No. 333-186227) under the Securities Act of 1933, as amended (the “Act”), filed on January 25, 2013, as amended by Pre-Effective Amendment No. 1 on April 12, 2013 (as amended, the “Registration Statement”).

On September 17, 2014, Ally Auto and Ally Bank entered into an Underwriting Agreement with Credit Suisse Securities (USA) LLC, Barclays Capital Inc. and Merrill Lynch, Pierce, Fenner & Smith Incorporated, as representatives of the several underwriters named therein (collectively, the “Underwriters”), for the issuance and sale of certain asset backed notes of Ally Auto Receivables Trust 2014-2 (the “Issuing Entity”) in the following classes: (i) the Class A-1 Asset Backed Notes (the “Class A-1 Notes”), (ii) the Class A-2 Asset Backed Notes (the “Class A-2 Notes”), (iii) the Class A-3 Asset Backed Notes (the “Class A-3 Notes”), (iv) the Class A-4 Asset Backed Notes (the “Class A-4 Notes” and together with the Class A-1 Notes, the Class A-2 Notes and the Class A-3 Notes, the “Class A Notes”), (v) the Class B Asset Backed Notes (the “Class B Notes”), (vi) the Class C Asset Backed Notes (the “Class C Notes”), and (vii) the Class D Asset Backed Notes (the “Class D Notes” and together with the Class A Notes, the Class B Notes and the Class C Notes, the “Notes”). The Notes have an aggregate principal balance of $1,520,910,000. Only the Notes have been registered pursuant to the Act under the Registration Statement. The Depositor intends to sell the Certificates of the Issuing Entity in one or more separate transactions intended to be exempt from the registration requirements of the Act. It is expected that the Notes will be issued on or about September 24, 2014 (the “Closing Date”).

This Current Report on Form 8-K is being filed to satisfy an undertaking to file copies of certain agreements executed in connection with the issuance of the Notes, the forms of which were filed as Exhibits to the Registration Statement.

The Notes will be issued pursuant to an Indenture attached hereto as Exhibit 4.1, to be dated as of the Closing Date between the Issuing Entity and Deutsche Bank Trust Company Americas, as Indenture Trustee.

The Notes evidence indebtedness of the Issuing Entity, the assets of which will consist primarily of motor vehicle retail instalment sale contracts (the “Receivables”) secured by new and used automobiles and light duty trucks financed thereby.

On the Closing Date, the Receivables will have the characteristics described in the Prospectus Supplement, dated as of September 17, 2014, to be filed with the Commission pursuant to Rule 424(b)(5) of the Act on September 19, 2014.

Legal opinions of Kirkland & Ellis LLP are attached as Exhibit 5.1 and Exhibit 8.1.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Dated: September 19, 2014

EXHIBIT INDEX