Repacking bicycle bearings: should I clean the old bearings first, and if so,

[Eric H]

what should I use to clean them? This is a mid-1970's Schwinn. Obviously, if there is grit or dirt or rust I will clean them. My instinct is to use 3 in 1 oil if I must, then repack everything in good old reliable bicycle grease. But if there is just old grease without anything gritty, do I even need to clean the bearings etc., and if so, what cleaning agent do I use?

 

[McG]

To clean bearings of grease you want to use a solvent. Several are available. Find one of these; mineral spirits, kerosene, or brake wash (aerosol). Use a parts cleaning brush and don't drop a bearing. Once they hit the floor they run and hide. Hard little critters to find, too. I use a magnet to pull the bearings out unless the old grease is too thick. The balls themselves can be put in a jar or tin with the solvent and soaked. Clean the race with the brush. I use an old metal coffee can to place the hub over and dip the brush in the can. It runs back inside to contain the mess. If you have compressed air you can blow them dry. If not you can force a piece of clean rag through the hub to dry. Inspect the clean race for pitting. (If there is pitting the race needs replaced and in most instances that will require a new hub.)
Press the new grease in the race with your finger and place the balls one by one into the grease pressing them in. The new grease will hold the bearings from falling out. Don't worry if you think you are using too much grease, the excess will ooze out as you install the axle and you can wipe it off. Don't over tighten the axle nuts. There is a fine touch between play and over tight. With new grease I tighten them them to space the balls properly, then back off and tighten them for the proper feel.

 

[sno f]

brake cleen works the best. teflon bike grease is best but automotive wheel bearing grease works good too. i would just replace ball bearings regardless of how old they may be. yes clean out old grease.