I know some of you use Timken Bearings. My question is my son is working on his 85 Trans Am, he ordered bearings for the front rotors, I was checking to see if he got all the parts and notice the outer bearings have a plastic cage instead of a metal cage holding the taper bearings. Has anyone used this type of bearing? I've never installed a bearing like this.
Short answer, it's normal so don't worry about it.
Longer answer, your son's 3rd-gen F-body uses a SET34 outer wheel bearing, and they're all built to that spec, regardless of manufacturer. I've spoken to a couple bearing guys (engineers, field techs, etc) over the years about it and the general consensus was that it was necessary in certain applications to reduce the frictional drag caused by the cage, which results in heat and can lead to other failure mechanisms, thus shortening bearing life. The SET34 bearing is a bit of an oddball that was generated to basically replace the older SET2 bearings (.750" ID) with the same OD, length through bore and load ratings, but have a .844" ID. It was mostly a GM thing as far as I know.