POWER OF ATTORNEY



         KNOW ALL PERSONS BY THESE PRESENTS, that I, John P. Wiehoff, hereby
constitute and appoint Norman C. Linnell, Amy C. Becker and William M. Cook, and
each of them, my true and lawful attorneys-in-fact and agents, each acting
alone, with full powers of substitution and resubstitution, for me and in my
name, place and stead, to sign any reports on Form 3 (Initial Statement of
Beneficial Ownership of Securities), Form 4 (Statement of Changes in Beneficial
Ownership of Securities) and Form 5 (Annual Statement of Changes in Beneficial
Ownership) relating to transactions by me in Common Stock or other securities of
Donaldson Company, Inc., and all amendments thereto, and to file the same, with
the Securities and Exchange Commission and the New York Stock Exchange, Inc.,
granting unto said attorneys-in-fact and agents, and each of them, or their
substitutes, full power and authority to do and perform each and every act and
thing requisite or necessary to be done, as fully to all intents and purposes as
I might or could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, and each of them, or their substitutes, may
lawfully do or cause to be done by virtue hereof. This Power of Attorney shall
be effective until such time as I deliver a written revocation thereof to the
above-named attorneys-in-fact and agents.


Dated:  July 25, 2003



                                                             /s/ John P. Wiehoff
                                                             -------------------
                                                             (signature)
                                                             John P. Wiehoff