Topic: CB400F swing arm bushings

[timbo]

Hello,

Somebody has had a go on making brass swing arm bushes for a CB400F?
I have a lathe,and bearing brass. Somebody got dimensions for the collar?

regards

Tim

[awrawr]

I have a pair loose. Which dims are you after?

[awrawr]

How about this?

[timbo]

thanks a lot,I wil have a go this weekend.

[Bodi]

Probably lubrication was ignored by previous owners, with regular greasing the original composition bushings should last almost forever. If so, the collar that turns in the bushings usually wears as well, becoming oval rather than circular. And the collar has been NLA for so long that finding a new one is nigh on impossible.
But:
Measure the swingarm bore and make the bushing OD a press fit, maybe 2 thou oversize? Also measure the collar (see if it's oval, it is possible to have it ground undersize and round) and allow some clearance, not sure what's best for clearance on these. Note that the ID will shrink a bit when the bushing is pressed in.
Machining them will be difficult because they are rather thin. I would loctite it to an arbor with tight fit to the ID and machine the OD that way. If I had access to a machine shop, that is. Which I no longer do.
I bought 3 brands of bronze/brass bushings and all were unusable, the ID was too big. I pressed one in to see if it would tighten up, but nope. Honda replacement ones fit nicely, still tight, I grease them at least annually.

[maxheadflow]

Personally, if you are cutting from bar, you can turn the whole thing and part off.  I'd shoot for 1/2 to 1 but since you are only asking the collar size it sounds like you are figuring ID / OD / length by fit on the parts you got. Nice to tighten them up a little and custom fit the part.

[Tracksnblades1]

Probably lubrication was ignored by previous owners, with regular greasing the original composition bushings should last almost forever. If so, the collar that turns in the bushings usually wears as well, becoming oval rather than circular. And the collar has been NLA for so long that finding a new one is nigh on impossible.
But:
Measure the swingarm bore and make the bushing OD a press fit, maybe 2 thou oversize? Also measure the collar (see if it's oval, it is possible to have it ground undersize and round) and allow some clearance, not sure what's best for clearance on these. Note that the ID will shrink a bit when the bushing is pressed in.
Machining them will be difficult because they are rather thin. I would loctite it to an arbor with tight fit to the ID and machine the OD that way. If I had access to a machine shop, that is. Which I no longer do.
I bought 3 brands of bronze/brass bushings and all were unusable, the ID was too big. I pressed one in to see if it would tighten up, but nope. Honda replacement ones fit nicely, still tight, I grease them at least annually.

👍

And if you have a machine shop with a full set of precision reamers, then you can re established your desired ID clearance after pressing in your bushing.

[timbo]

Hello,

Did some work on them yesterday but did not have time to finish them.
I had the swing arm powder coated but forgot to take the original bushings out so I have to renew them.
I read somewhere that a brass bushing would do a better job so I want to give a go at making them. I was planning to
make them from bar. was not sure about the collar thickness so I asked it here. was planing to ream them to size after pressing in.

[Bodi]

Decent plan. The bushings are quite thin, I would be dubious about them holding up in a lathe but with really light cuts it may be OK. I would bore the ID close and then gingerly turn down the OD.
Some theories say that reaming oilite will seal the surface and reduce lubricity, I'm not sure about that. I do have a few adjustable reamers (none that big) and have reamed valve guides successfully but they aren't oilite.
Unless you're in love with Bronze, the Honda non metallic bushings seem pretty good to me. Your main worries are 1) getting the old ones out and 2) are the collars round and in spec. Plus they are pretty easy to ruin while pressing in, some sort of supportive collet would be helpful.
You can try an extractor made from a washer that just fits the bore, file flats on it so it will fit down behind a bushing, then use a press, threaded rod, or bolt to pull or push it out. If that fails you have to cut through it with a hacksaw blade trying not to notch the bore too much, then bust it out with a chisel or screwdriver. They will be quite well stuck in there after many years.

[timbo]

I got the old ones out with litle efford,I think the baking of the powdercoat got them loose.
I just drived them out with a screwdriver. I wil give the brass a go first. I reamd oilite before in the past,it is possible with a good sharp reamer.
But I was not planning to make them in oilite. I was planning to use plain bearing brass. The bushings can be grased so this would work fine I think.

[timbo]

Just wanted to let you know I finished the bushings today.
The dimensions that awrawr gave me where spot on except for the collar width.
these where to wide and did not allow me to instal the two washers with the seal.
Took me some messuring and fiddling but it worked out great.

regards

Tim

[Scott S]

 A lot of the brass/bronze bushings I've used don't need the felt seals, etc.