How do you tell if bearings are shot? I am redoing my front suspension and noticed I could turn one side easier than I could the other. The one that is more resistant has a weird metal sound at the same spot in the rotation every revolution. I popped off the grease caps and noticed blue grease and a new cotter/nut so I am assuming the previous owner might of had them done recently. Any thoughts?

 

Residual pressure on the brake pads. They are constantly in contact with the rotors and will drag a little. That is normal. I would not be afraid to check the bearing adjustment by pulling the cotter pin and checking the tightness (torque) of the nut. For that matter, if you are concerned enough to be asking about it, I personally would pull the hubs and make sure everything is OK. It's more work but it's hard to put a value on peace of mind.

 

Thanks Casey. I have the whole assembly off the suspension with the rotors off so it is not the brake pads. I am curious more so than concerned - I just don't know how to tell. I guess I should just pull them apart to check. How loose do you leave the nut?

 

Wash all of the grease off the bearings and races (leave the races installed, of course). Look at the roller and race surfaces with a good light and up close. You are looking for any 'frosted' [not shiny] surface condition or something with tiny scuffs/gouges in the surface. Or, you might find an area of gouging which would indicate that the bearing had some hard metal particles that had run through it.

A "frosted" surface would indicate excessive surface loading/wear (possibly running dry), resulting in the very top layer of the bearing materials being eroded. A good, clean bearing surface would remain shiny and polished. Rarely, you might find a bearing that shows significant heating...bluish in color, indicating that the bearing was likely tightened to much at installation.

If you see these kinds of conditions, you need to replace that/those bearings. But, you also need to clean the brake drum and spindle VERY well with solvent to rid it of all old grease that could be carrying hard particulate with it. Knock the old races out; drive the new ones in to full depth. PACK THE NEW BEARINGS WITH A GOOD BEARING GREASE. I would recommend a synthetic grease, as it will last much longer without losing lubricity and will not be affected by heat so much.

When you pack bearings with grease, you don't just slop some on the surface. You need to squeeze grease completely throughout the bearing so there are no/few air pockets internally.

 

The shop manual for my 79 says the hub should have between .001" and .005" of movement. To adjust the wheel bearing tighten the nut to 12 ft. lbs. while turning the wheel forward. Back off nut to loose and retighten by hand to fully seat bearings. Loosen nut until cotter pin can be inserted. Not more than 1/2 of a flat on the nut.

 

Here is a good article:
http://www.corvettemagazine.com/tech...g-replacement/
The nut should be tightened just enough to take all the movement out of the bearings. Tighten it up by hand while slowly spinning the hub. When you can't wiggle the hub it should be tight enough. I can't find a specific torque spec for it, just the instruction to hand tighten it until the play is removed. That is the way I've always done it, but I wanted to make sure there wasn't a specific spec.

 

Thanks everyone! I will take them apart and have a better look. That link is awesome - thanks Casey!

@ 7T1vette - any recommendations on a brand specific synthetic grease?

 

Lucas 'Red & Tacky' for one; Green Grease (yep, that's the name) is another. About every car parts store has something that will work...either in a can or in a grease gun tube.

I'm a believer in the benefits of synthetic lubricants. If nothing else, the fact that the stuff will stay in the bearings [under heat & load] is good enough for me.