Author Topic: Crankshaft shimming  (Read 1792 times)

Offline Wayno

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Re: Crankshaft shimming
« Reply #45 on: 07.07. 2018 13:18 »
Yes, they are the ones as supplied by Draganfly.  They do look very sturdy and well made. I'm now looking into acquiring a bearing separator to fit around the rollers (as suggested by muskrat) so I can remove the inner race without damaging it and adjust the end float.
I suppose one idea to avoid removing the race too many times is to temporarily place the shims between the crank and the bush (if that's possible) just to achieve the 0.001 - 0.003 thou end float then remove the inner race once and place the shims in their correct position.
Any comments on that thought guys?

Online muskrat

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Re: Crankshaft shimming
« Reply #46 on: 07.07. 2018 15:14 »
G'day Wayno.
Theoretically that would work BUT! Every time the outer race is inserted and removed from the case the crush on the race may diminish. The race is a C3 fit meaning it needs a certain amount of crush to bring it to the right dimensions (roller clearance). First you would need to assemble without shims and measure the end float to work out the shims needed. Then remove the race and put the shims in and assemble to check the end float. Then pull it all apart again to put the shims where their supposed to be behind the inner race. Seems like a lot of unnecessary work and risking the outer race fit in the case. 
The correct way (mine anyway) to remove the outer race is to heat the case to about 200C, the race usually falls out. To insert heat the case and freeze the race. It will drop straight in.
With the shims where their supposed to be (behind the inner race) and the cush nut is done up to 65 ft/lb they are trapped and can't move. If its set up with one or two thou" end float and the shims are behind the outer race there is a possibility the outer race can move that amount and the shims are loose.
Just do it the right way and we won't have to get the trailer to rescue you! LOL.
Cheers
Edit: Some people have an inner race with a honed bore that slips on the shaft easily to take the end float measurement. Then replace with the new race. I don't subscribe to that method as there may be small differences in the race/roller dimensions, but it works for them.
Double edit: DOH, just re read your last post re shims on the other side. That could work.
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Offline duTch

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Re: Crankshaft shimming
« Reply #47 on: 07.07. 2018 16:49 »
 
Quote
......I suppose one idea to avoid removing the race too many times is to temporarily place the shims between the crank and the bush (if that's possible) just to achieve the 0.001 - 0.003 thou end float then remove the inner race once and place the shims in their correct position.
Any comments on that thought guys? 

 I'm not sure what Musko is on  *whistle* or if I just read it wrong, but Wayno if you mean between the sprocket bush and crank, it won't achieve anything, as it's just packing the bush out and they still move together... *spider*...- or if you mean the T/S Main bush, it's a bigger diameter so also fairly unlikely to work.... *conf2*
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Offline Wayno

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Re: Crankshaft shimming
« Reply #48 on: 08.07. 2018 10:51 »
Gents-  I think the heat is affecting what few brain cells I have!!  I did mean to temporarily put the shims between the crank and the T/S bush but of course dutch you are quite right the dia is bigger so no go.  I have removed the old inner race using muskrats method of boiling water and I was stunned when it came off so easily leaving plenty of water for a well need cuppa :)
Armed with that knowledge, it should be straight forward to slip the new one on/off to adjust shims as you recommend.
Thank you all again for your experience.  Now need to sort crank either find a better one or risk grinding further.
Cheers all