Bushing That Just Don't Fit???

K

Kroll

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Dec 23, 2012
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Good morning guys,well my 9/16 x 11/16 bronze bushings came in yesterday and I press them into the gears.The first one is perfect and rotates on the shaft with a fingers spin and no more wiggle.Now the other gear is a different story,press it into the gear and went to put the shaft in but its a little tight.Its to where I have to turn the gear kinda screw it onto the shaft.Now that the gear is in the sweet spot of the shaft it does turn but not by fingers spin.Its like I need to remove just a shadow thickness,which means anything remove may be to much.So how would a person go about just removing a very small amount?The temptation would be to use sandpaper fitted around your index finger then rotate the gear couple turns but that's just not right.I did chuck up the gear and was going to give that a try but its not centered perfectly.
Guys I could just go ahead and install the gear the way it is cause I'm sure over a little use it will fit but just trying to help make it the best it can be.----kroll
 
sometimes just burnishing the bearing with a hard wood dowel will make the difference
 
First, verify that the shaft is truly round (I just purchased a new 17mm shaft that is three-lobed. I measures exactly 17mm, but when I tried to fit it into a 17mm bearing, it left three bright spots on the shaft. (polishing with 300 paper solved the problem). If the shaft is true, a bit of wet and dry 300 to 600 paper inside the bushing should be sufficient to remove any "high" spots. BUT, not wrapped around a finger, Use a piece 1/2 wide by 1 in long, lay it on the inside of the finger and gently press it against the turning bushing's insides, sliding it back and forth. Be very gentle, very cautious. Wash the bushing before assembly to remove any possible grit.
 
Color it up with a magic marker and put the shaft back in and see if it's just a high spot or if the dia got pinched down and where.

Brunishing is a good way to push a little metal around.
 
In my experience, pressing a bronze bushing into a heavy press fit will shrink the I.D. slightly. Bushings that would spin freely on the shaft before installing would be tight when installed. I've used a properly sized reamer to correct the situation. I have also made laps from a piece of dowel with a slit cut in the end with a doubled up piece of 400 or 600 grit wet or dry. You just have to make sure that you remove all the grit and residue.
 
Same as what RJSakowski said. I have pressed in bushings and the ID shrunked. I use a reamer to resize them. I have heard that with oil lite bushings to just do it enough to ream it or it will seal the pores in the bushing. Just in and a quick turn of the reamer and out by hand.
 
Thanks guys,off to the shop to give the dowel rod with w/d sandpaper and use black magic marker to see if I created any high spots using the press.Just to remove very little then then test fit.
 
RJSakowski said:
In my experience, pressing a bronze bushing into a heavy press fit will shrink the I.D. slightly. Bushings that would spin freely on the shaft before installing would be tight when installed. I've used a properly sized reamer to correct the situation. I have also made laps from a piece of dowel with a slit cut in the end with a doubled up piece of 400 or 600 grit wet or dry. You just have to make sure that you remove all the grit and residue.
Click to expand...

I have used this method many times through the years with great success.
 
don't listen to him about not using your finger lol, there is safe, and unsafe, a small bore is where it can be unsafe, but I ALWAYS try and use my finger with sand paper or emery, I do not however wrap it around my finger, but you get the best feel with a your fingers. small bore? lap it like recommended above
 
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