(ET) What are hub set screws and reinforcements?

Subject: (ET) What are hub set screws and reinforcements?
From: Richard Zachary <njcfsa earthlink net>
Date: Mon, 01 Sep 2003 17:16:53 -0400
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Technical Services (Bill Gunn) included a sheet entitled "Purchasing aUsed Elec-Trak - Things To Do After."

I understood most of the recommendations except:
1.  Check the hub set screws (large frame only)

2. Make sure to install the reinforcements below the mower deck (whererequired)

Can anyone shed some light on these recommendations for a beginner.
Thanks,
Richard "Zack" Zachary

Follow-Ups:
- Re: (ET) What are hub set screws and reinforcements?
  - From: Steve Gaarder