I've always wanted to know what a freewheel looked like on the inside... So, since mine was loose, I decided to open it up! First, I want to say, if you plan to play with your freewheel like I did, be VERY careful not to spill the ball bearings all over the place (there are 94 in a Shimano 18 tooth, don't ask how I know! :-p), or you'll be having fun putting it back together (using Bullshot grease to get the bearings to stay in place). It was once said by a bike mechanic friend of mine, "There are some things you just shouldn't take apart."
Do I need to tighten/loctite my freewheel?
Here's how you know: Grab a tooth on the freewheel (the section that isn't in contact with the chain is good) and try to wiggle it side to side. If you can, you ought to tighten it. If you can wiggle it like 1 mm or more, you really need to tighten it...
How to loctite your freewheel...
- Red Park Tool Spanner Wrench (SPA-2)
- Red-colored loctite
Top cap: Clockwise loosens, counter-clockwise tightens.
Keep the freewheel perfectly level while loosening the top cap (I had to "span out" the spanner wrench a bit to make it fit in both holes), making sure not to spill the bearings. Put loctite on the top cap's threads (but not the threads on the freewheel itself, I think it may get into the pawl mechanism, and that would not be fun...), and thread it back in, nice and tight. Let the sucker sit for a day so it totally sets.
How do I tighten my freewheel in an emergency (when I don't have all the tools)?
In a pinch, and I MEAN in a pinch, you can use a small tipped screwdriver (or similar object with a small enough head, my keychain swiss army knife worked...) to tighten a loose freewheel by backpedalling with the screwdriver firmly in the hole, wedged against the chainstay. It'll last you a little while (check it frequently!)...
Shimano freewheel with bearings not in just yet
ACS freewheel with just the cap taken off (I put blue loctite on the threads and put it back together)
Shimano freewheel in pieces (94 ball bearings on left almost out of view)
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