Bicycle Mechanics - How to tighten SRAM Rival Crank

Got a 2012 CAAD10-4 with Rival.

I've got a couple hundred miles on it and today it was really creaking as I rode. I put it on the stand when I got home and immediately noticed the crankset is loose. There's a half-inch of play in it and it wobbles easily. I further noticed that with SRAM I have no idea how to tighten it!

I can see straight through it to the other side of the bike but there are four small indentations with torque specs and an arrow on them. I imagine you put some kind of tool with four prongs in here and tighten clockwise. Looking in my handy-dandy Park Tool Kit I don't see anything like that.

Moving to the non-chain side of the bike there's kind of a washer and a knob you can turn with your hand. It doesn't appear to do much and there's still tons of play in the crank.

I can take it to the shop on Sunday but what a pain. Am I missing something or am I gonna need yet ANOTHER special tool?

Thanks!

This link should tell you everything you need to know: http://www.sram.com/sites/default/files/techdocs/95-6115-007-000%20Rev%20A%20-%20Road%20Cranksets_3.pdf

The 4 hole component is a self-extractor cap. There should be a hex recess bolt visible in the center of it. when you back that bolt out the extractor cap will push the crank arm off the splined axle (a very handy feature).

If you truly have a 1/2" of play at the crank arm, something is seriously wrong. You may have had a bolt back out and if that happened, chances are your crank is toast as the splined interface will be permanently damaged. Read through the PDF and follow the instructions for tightening the crankset. Without seeing the bike firsthand it's difficult to say how severe the problem is. Hopefully a re-torque fixes it.

Thank you for the response and for the link. I suspect I've got some major issues. It was really grinding on the ride home.

I'll take it to my bikeshop and have them look at it.