Semi circle of metal

[Stu_22]

Where the crank dmaper pulley slides on.

Probably a really simple newbie question but whats it for?

 

[thelonerider]

Where the crank dmaper pulley slides on.

Probably a really simple newbie question but whats it for?

Your question is not very clear, but I am guessing it is an issue some owners have. The timing belt pulley which is behind the crank dampner/cover has a lip on both sides and the front one sometimes breaks off. This causes the belt to move off the pulley. You need to tack the ring back onto the pulley.
Here is a link to a discription to the problem, but unfortunately, it is in French, but there is pictures. :biglaugh:
http://supraquebec.com/modules.php?name=Forums&file=viewtopic&t=3251

 

[SevenMKIII]

The woodruff keys are there to hold the crank pulley from wobbling around on the crank. You want to make sure you buy them from Toyota if you replace them, they're only $2.50 a piece. Damaging your crank...a new one of those is about $900.

 

[IJ.]

The Keys Locate the pullies to set a timing position relative to the Crank.