i realized i was missing something rather important on my 280zx a day ago and for the life of me i can't think of what it is called could someone help me out?

its the gold colored piece

Bearing dust cover

Thanks Arne

I came to noticing it when all of a sudden my z jerked to the right i found metal shavings in it too... >.< its only been a few miles that it had to be like that, so do i just have to put in more grease and put the cap back in?

If you found metal shavings in the bearing assembly, it's time to change them out for new ones!

I don't know alot about cars, but i really want to do all of this myself, does anyone know where i can get the dust cover and bearings from?

Try your local Nissan dealer, that is where I got mine from. If not there, MSA has them in stock.

It's important that the cap keep the grease in there for the bearing, best to put some grease in the cap, and then push it on.

what you are really missing is the plastic piece that covers up the grease cap. it is chrome colored and has a Z on it. not to say your wheel bearins aren't ready to quit working tho.