GALLOP, JOHNSON & NEUMAN, L.C.
                            Interco Corporate Tower
                                 101 S. Hanley
                              St. Louis, MO 63105


                                 March 26, 1997


Board of Directors
Top Air Manufacturing, Inc.
317 Savannah Park Road
Cedar Falls, Iowa  50613

         Re:      Registration Statement on Form S-8; Amendment No. 2 to Top Air
                  Manufacturing, Inc. Stock Option Plan

Ladies and Gentlemen:

         We  have  served  as  counsel  to  Top  Air  Manufacturing,  Inc.  (the
"Company") in connection  with the various legal matters  relating to the filing
of a registration statement on Form S-8 (the "Registration Statement") under the
Securities Act of 1933, as amended,  and the Rules and  Regulations  promulgated
thereunder,  relating to 175,000  shares of common stock of the Company,  no par
value (the  "Shares"),  reserved  for  issuance in  accordance  with the Top Air
Manufacturing, Inc. Stock Option Plan (the "Plan").

         We have examined such corporate  records of the Company,  such laws and
such other  information  as we have deemed  relevant,  including  the  Company's
Articles of Incorporation,  and Bylaws, certain resolutions adopted by the Board
of Directors of the Company relating to the Plan and certificates  received from
state officials and from officers of the Company. In delivering this opinion, we
have  assumed  the  genuineness  of  all  signatures,  the  authenticity  of all
documents  submitted to us as originals,  the conformity to the originals of all
documents submitted to us as certified, photostatic or conformed copies, and the
correctness of all statements submitted to us by officers of the Company.

         Based upon the foregoing, the undersigned is of the opinion that:

         1.     The Company is a corporation duly incorporated, validly existing
                and in good standing under the laws of the State of Iowa.

         2.     The  Shares  being   offered  by   the  Company,  if  issued  in
                accordance   with  the  Plan,   will    be  validly  issued  and
                outstanding and will be fully paid and nonassessable.

         We consent to the use of this opinion as an exhibit to the Registration
Statement  and to the use of our  name in the  Registration  Statement.  We also




Board of Directors
Top Air Manufacturing, Inc.
March 26, 1997
Page 2

consent to your filing copies of this opinion as an exhibit to the  Registration
Statement  with  agencies of such states as you deem  necessary in the course of
complying  with the laws of such  states  regarding  the  issuance of the Shares
pursuant to the Plan.

                                    Very truly yours,


                                    /s/ GALLOP, JOHNSON & NEUMAN, L.C.