You're only changing the URI that's sent to the server; there is no change on the client side. If you need to change it to https presumably you want to use SSL between the client and the server (rather than just between the Big-IP and the server). In that case you'll want to use a redirect:
HTTP::redirect "https://myclaytonbenefits.com/SHCM/"
This sends a temporary redirect to the client (302). If you need to use a permanent redirect (301) you need to use HTTP::respond.
Keep in mind that redirects cannot be stacked in a single connection; if you have a VS with multiple iRules with redirects you'll run into problems unless you take certain measures.
Nimbostratus
