New bronze swingarm bushings need to be "align-reamed&q

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JimP

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I've installed new bronze bushings in swingarm. My new (standard size) spindle fits perfectly in each bushing individually, but not through both at the same time! I've re-indexed the bushings to no avail; the non-concentricity simply follows the bushings.
Has anyone else had this experience? Is it common to have to "align-ream" the bushings after they are installed?
Thank you, Jim P. Detroit
 
Jimp,
Some do need line reaming. Could be the boss bores are heavily coated with paint, or more likely in your case they're out of line. If you do line ream the bushes it might be better if you looked for a pair with tighter bores to ensure you ream a round bore.
Cash
 
I always thought that sintered bronze should only be 'bored' and not 'reamed'?
Reaming supposedly clogs the highly porous sintered Oilite material, unlike phosphor bronze where there is no problem as it doesn't rely on the porosity of the bearing material to lubricate the bearing surfaces?
 
This would be like tweaking a lower triple tree in so that the legs sit flat and parallel. Using a surface plate and a indicator mounted on a hight gage, determine if your swing arm is bent before proceeding.
By putting a short threaded rod with thick washers and tightened nuts on each side of one tube of the bushing supports a bit of tapping and rechecking should put it all back in true. Rechecking your progress after each tapping with the indicator on the surface plate is time consuming because of needed to pull the tapping appliance out for each re-check. You can PM me for a phone# I am up in Flint this is not as bad as it seems and hard to write all out.
 
LAB,

Reaming sintered bronze is an acceptable method as it's a cutting action, grinding and honing not, the nasty little abrasive bits get stuck in the pores. After boring on a lathe the bush should be soaked in oil for at least 12hrs to replentish the oil thrown out by centrifugal force. It's probably a good idea to soak any sintered bronze bush in oil just incase the manufacturer didn't.

Cash
 
cash said:
Reaming sintered bronze is an acceptable method as it's a cutting action, grinding and honing not, the nasty little abrasive bits get stuck in the pores.
Click to expand...

But a sharp reamer must be used, apparently?: http://www.mmdigest.com/Archives/Digest ... 14.14.html

Quote:
_________________________________________________
Bernt Damm's comment about reaming reminds me that a common mistake in
machining sintered bronze is to use dull tools. If a reamer, or other
cutting tool, is dull, then the metal being machined is smeared over
the pores, which effectively shuts off the lubricant source. Rapid
failure results. Sharp machine tools are a *must*.
________________________________________________
 
Agree absolutely.
I'm sure Norton did specify a special tool to line ream the swinging arm bushes. There's one thing for sure it can be a real pain in the neck if you don't have access to the correct tooling.

Cash
 
Thank you Cash and L.A.B.
I'm encouraged by the easy solution to buy a .875" reamer and simply "running it through". Is that something I can do by hand? The reamers that I see for sale only have a few inches of cutting blade length. It's not clear to me how I would aim the reamer to "hit" the center of the bushing on the opposing side.
I have norbsa48503's phone number. I'll call him tonight to see if we can think of something! Jim P.
 
Jim no matter what you need to get it up on a surface plate to see if it's bent they often are by the way. Once you have gone the far tapping it into line is not what you would call a hard job.
 
JimP said:
I'm encouraged by the easy solution to buy a .875" reamer and simply "running it through".
Click to expand...

My only concern would be that if you start removing metal from the bushes which you have described already as being a perfect fit on the spindle, that you may end up with too much bearing clearance?

I would be inclined to go with Norbsa's idea and attempt to straighten it?
 
JimP,
As LAB and norbsa point out it's not a simple matter. You would need the earlier bushes that were supplied with a smaller inside diameter and did require line reaming. The line reaming tool is a special bit of kit usually designed for one specific job. However, a decent machine shop could do it for you.
I reckon if you can straighten the bosses that's the way to go, you wouldn't have the same problem next time.

Cash
 
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