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                                                           Exhibit 10.1(aa)

                      STOCK PURCHASE AGREEMENT

     This Stock Purchase Agreement is made as of the 31st day of March, 2000,
by and among SAUER, INC., a Delaware corporation (the "Company"), and TONIO
P. BARLAGE AND MARIA BARLAGE, husband and wife ("Sellers").

     Sellers own 600,000 shares (the "Shares") of capital stock of the
Company. Tonio P. Barlage and the Company are parties to that certain
Termination Agreement dated of even date herewith, pursuant to which they
have agreed that Sellers will sell, and the Company will purchase, the Shares
upon the terms set forth in this Agreement.

     The parties, intending to be legally bound, agree as follows:

     1.   PURCHASE AND SALE OF SHARES.  Subject to the terms and conditions
of this Agreement, no later than April 10, 2000 (the "Effective Date"),
Sellers shall sell the Shares to the Company, and the Company shall purchase
the Shares from Sellers for a purchase price per share (the "Purchase Price")
equal to the sum of the closing stock price for the Company's common stock as
set forth in THE WALL STREET JOURNAL for each trading day during the period
January 1, 2000, through March 31, 2000, divided by the number of trading
days used to arrive at this sum. For example, if there are 61 trading days
during said first quarter and the sum of the closing prices for such trading
days as set forth in THE WALL STREET JOURNAL was $793, the Purchase Price
would be $13 and the total payment to Sellers would be $7,800,000. Sellers
authorize and direct the Company to withhold in accordance with applicable
law from any payments made to Sellers under this Agreement all payroll taxes
and other payments required to be withheld by the Company under federal,
state, or local laws. The determination of the amount of any such withholding
shall be made by the Company in its sole discretion. Based on the published
closing stock prices, the Purchase Price is $9.5367.

     2.   RELEASE.  As part of the consideration for the Company's payment of
the Purchase Price, Sellers hereby forever release and discharge the Company
and its subsidiaries and affiliates and their past and present officers,
directors, employees, agents, representatives, stockholders, advisors,
counsel, joint venturers, partners, predecessors, successors and assigns, and
all other related persons, corporations and other entities who are or might
be liable (all of the foregoing collectively referred to as the "Released
Parties"), from all claims, rights of action, causes of action, liabilities
and demands of every kind and character whatsoever, known or unknown,
developed or undeveloped, which Sellers individually or in any and all other
capacities, now have or under any circumstances could or might have against
any or all of the Released Parties in connection with, arising out of, or
regarding in any way Sellers' acquisition, ownership, or disposition of the
Shares.

     3.   DELIVERIES.  On or before the Effective Date, Sellers shall deliver
to the Company certificates representing the Shares, duly endorsed (or
accompanied by duly executed stock powers) for transfer to the Company, and
the Company shall deliver to Sellers the Purchase Price.

     4.   REPRESENTATIONS AND WARRANTIES OF SELLERS.  Sellers jointly and
severally represent and warrant to the Company that Sellers are the record
and beneficial owners and holders of the Shares, free and clear of all liens,
pledges, encumbrances, charges, assessments, or claims of any kind

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whatsoever ("Encumbrances") and that Sellers shall deliver to the Company
good and marketable title to the Shares, free and clear of all Encumbrances.
Sellers will indemnify and hold harmless the Company for, and will pay to the
Company the amount of, any loss, liability, claim, damage (including
incidental and consequential damages), expense (including costs of
investigation and defense and reasonable attorneys' fees) or diminution of
value arising from or in connection with the breach of the foregoing
representations and warranties.

     5.   FURTHER ASSURANCES.  The parties agree to furnish upon request to
each other such further information, to execute and deliver to each other
such other documents, and to do such other acts and things, all as the other
party may reasonably request for the purpose of carrying out the intent of
this Agreement and the documents referred to in this Agreement.

     6.   ENTIRE AGREEMENT AND MODIFICATION.  This Agreement supersedes all
prior agreements between the parties with respect to its subject matter and
constitutes a complete and exclusive statement of the terms of the agreement
between the parties with respect to its subject matter. This Agreement may
not be amended except by a written agreement executed by the party to be
charged with the amendment.

     7.   GOVERNING LAW.  This Agreement shall be deemed to have been
executed in Ames, Iowa, and the validity, interpretation, construction, and
performance of this Agreement shall be governed by the laws of the State of
Iowa applicable to agreements made and to be entirely performed therein,
without regard to conflicts of laws principles.

     IN WITNESS WHEREOF, the parties have executed and delivered this
Agreement as of the date first written above.

                                SAUER INC.



/s/ TONIO P. BARLAGE            By: /s/ DAVID L. PFEIFLE
-----------------------------       ------------------------------------------
TONIO P. BARLAGE                    David L. Pfeifle, Executive Vice President



-----------------------------
MARIA BARLAGE


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