Okay, I know that both of my front wheel bearings are loose, as I have tested both wheels as is indicated in my Haynes manual (hold the top and bottom of the tire and rock in and out with the wheels pointed straight ahead), and both are loose. Now, I have adjusted these TWICE as is shown in both my Haynes manual and in my automotive suspension textbook, which has a diagram in it that comes straight from GM itself. I have tightened both nuts to 15'lbs (spec is 12) , backed the nuts off until loose, and tightened them again until I could insert the cotter pins (usually backing off slightly from hand-tight to line up the holes). Should I try working the nuts to, say, 20-25'lbs? My textbook indicates that I can go up to 30'lbs before I need to replace a bearing...

I still get a bad vibe going down the road, especially above about 60 MPH. I still have to figure out why the PS front caliper is causing a brake pulsation, but that shouldn't have anything to do with why the wheel bearings are still loose...

well if they have been run loose for a while they are probaly gone now but if they are still ok i usually tighten them up till i no longer have any play in them and then i take them just far enough more to insert the pin. i have yet to have them fail when done this way and i have done it a few times. at first i was doing them the way you described and they always went bad after only a short period of time so i started doing them this way and i have had the current ones for 6 months of Gravel/dirt roads, Mud, snow, and the occasional pothole and they havent even started to loosen. they were lasting at best mabe a month or so before crapping out on me.

you also might want to check you BallJoints and strut mouts i had what i thought was bad bearings which is why i replaced them in the first place and it was still there, well i was trying to figure out what was moving on me and i realized that it wasnt the brearings but the ball joints(I noticed the calipers were moving with the rotors and not the rotors inside the calipers). I also had a torn strut mount on one side.

Here's how I always tighten wheel bearings: Tighten the bearing while spinning the wheel. I go by feel with a ratchet, you seem to like torque wrenches, either way is fine. Back the nut off, tighten so it's just snug, put in the cotter pin.

Also, about your vibration, get your tires balanced. Unbalanced tires cause vibrations, especially abouve 60 mph. When a wheel bearing goes bad it makes a growling/moaning noise. Not a vibration.

Also, your brake pulsation is caused by the rotors. If you feel it in the wheel it's the fronts, if you can't feel it in the wheel but more in the seat it's the rear. Calipers don't cause a pulsation. Rotors do. Replace them or have them turned at a machine shop.

If you drove the car with loose wheel bearings then the rotors were moving side to side as well and the braking force was applied unevenly to them causing the pulsation you now feel.Make sure you are spinning the wheel when you tighten down the bearing as this will seat them correctly/fully,that may have been what has caused the "loose" feel.
Good luck,
Mike

1. Brake Problem: BAD DS rotor (rusted up on me and now about 1/2" of the outer edge seems to have caught some of the pads' friction material in them). The PS rotor is less than 2 months old (about six weeks actually) and looks brand new.

2. I readjusted the PS rotor (no play!) and now the vibes are reduced at 60+.

3. Front tires were just replaced and have less than 4000 miles on them. The rears need to go before my NYS inspection...

But, thanks for the input!

FYI: You should always replace brakes in pairs (i.e. both fronts or both rears). That goes for pads and/or rotors. Having an old setup on the left and a new setup on the right (or vise-versa) could cause problems under heavy braking.

For one, both of the rotors would have been the same age had it not been for the fact that two of the wheel lugs on the driver's side snapped off during an ice storm (yeah, I know--F-body+ice storm=accident waiting to happen ) and I only had enough funds and time at the time to replace the one, since I was 475 miles from home at the time (that cheapo POS cost me $130 to replace because I had NOTHING to work with at the time! )
I have yet to have any problems other than these damn rust spots, and the brake pull I had because my old tie rods were worn out (which is gone now), and if I do, it's because I have low tire pressure in one of the tires...

And yes, next month, I will replace the other rotor (right now, I'm putting in a decent sound system, and I had to replace my cat convertor at the time I replaced the PS rotor, so I couldn't afford 2) as the season ends.

BTW, how do I keep the rotors from rusting during the winter storage months?