Freewheel body service



davereo

Well-Known Member
Jun 17, 2010
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I have a 7 speed mountain bike with a Shimano Mega Range Freewheel. I have been using this bike on my trainer and towing a trailer bike.

The freewheel ratchet pawls no longer engages properly. I removed the wheel and the freewheel is free in both directions. If I spin it SLOWLY backwards it sometimes engages. I was able to get a replacement and removal tool for under 20 bucks at Amazon so I replaced it.

My question is would it be worth it to get a pin spanner and try servicing the freewheel to keep as a spare?
 
Is it worth trying to repair this?

Should I just make a lamp for my workshop with it as a base?
 
Get a can of WD-40. With the small cog side up, spray the WD-40 into the small gap between the lock ring and the freewheel body. Rotate the freewheel as you spray. What is probably happening inside your freewheel is that the pawls have gotten dirty and are sticking. Spraying it with WD-40 until the WD-40 is running out of the back side, and spinning should flush out the gunk that is causing the pawls to stick. After you have it working like it should, take a medium weight oil and lubricate the freewheel by dripping it into the same space where you sprayed the WD-40 until it starts to drip from the back side. Also do this while spinning the freewheel. I like to use motor oil as it stops the clicking of the freewheel.

If this doesn't work, there would be no harm in taking it apart. Usually if the cleaning procedure did not work, then the pawl spring may have slipped out of place. Just disassemble it over top of a dishpan to catch all of the little bearings that are going to fall out of it. Sheldon Brown has disassembly instructions in this link: http://www.sheldonbrown.com/freewheels.html under Freewheel Body Servicing. Although Sheldon says that the freewheel body is generally not worth the hassle to service, I never had a problem with it. But like he says, most of my freewheel servicing was for non-replaceable freewheels. Just try to find a racing corn cob in this day and age.
 
Great sounds like an easy fix. I will pick up some WD and give it a try. Thanks