Be aware that the missing bolts are an indication of a bigger problem.
Be SURE you install these 2 upgraded braces between the Hydro's. This is a known problem so inspect your mower now to see if it has the upgraded brace and I strongly recommend adding the additional upper brace too. Check that the bolts don't loosen up as we have had reports of that. Mine have stayed tight since the installation of the braces.
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Lower Cross Brace #123292 About $137. BUT this should be a warranty part if your machine did not come with it from the factory.
Upper Brace is called a "Clutch Cover" #120838 About $12.50
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