Friday, October 4, 2013

What not to do in freehub servicing?

This 7 speed Shimano HyperGlide Freehub was taken apart. All the dirty lube was taken off and the inner unit of the Freehub was reassembled. Then the pawl ends sprung out much faster.

But, unlike Simon Rakower's instructions, I assumed the Mag-1 lube had physical properties like Lubrimatic's boat trailer bearing grease, and I also meshed this with another wrench's advice to piddle Phil's Tenacious Oil through the whole unit (not sure if he really said the whole unit now). So like a 1mm coat of the Lubrimatic grease was applied to the inner bearing track on the pawl niched part of the freehub, and the same amount of grease was applied to the outer bearing track on the splined part of the freehub. Then Phil's oil was splooged all over the pawl niched part with the spring and the pawls on it. I forgot to add the washer stack back on top of the little thing before screwing the bigger bearing race back on and spinning the splines around the part usually held against the wheel hub shell, which I guess splooged some of the thicker Lubrimatic grease into the pawl area. I unscrewed this race and put the washer stack back in, but didn't test the pawl-spring responsiveness with the outer freehub splined part off after the bigger bearing race was screwed on for the first time that night. Then I just screwed back on the race with the lube where it was. Reading all those instructions as one goes is nice.

Fast forward an hour or two later, and coasting the bike at over 20 mph got the top part of the chain to depress like over an inch closer to the chainstay. I guess I won't pedal backwards in these times. Later figured the chain was about 3", or 3 links, too long, but, ya. Hope the thing doesn't skip unpredictably for a while, rain or shine, while riding the way I used to. Or Phil's isn't appropriate, or the quantity of that or the Lubrimatic grease wasn't the amount to apply.

pics!!


 It's one spring that likes to contract that holds both pawls in and sticks them out. The above dimple is where the spring is split.
The boat trailer bearing grease was applied to the ball bearing track in the above photo.

 This in a vise will do the trick to unscrew the race.
 But the EVT tool is nice with a torque wrench, and Shimano actually published recommended torque values for similar post-1997 races, even though they officially don't advocate taking like any of these apart.
The boat trailer bearing grease was applied to the visible track on the outer splied part.