Swingarm Pivot Bolt too tight a fit into Bushing (swing arm Bolt tube)

r570sv

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installing a new ushing (swing arm Bolt tube) Swingarm Pivot Bolt (Shaft) & bushings on my rear end

Bushing installed into the swing arm just fine
the shaft fits into the bushings just fine

Now when install the bolt into the pivot bolt shaft isn't going well. Way to tight a fit into it. I realize they have to work as one but I'm 100 heavy hammer strikes into trying to drive the bolt through and only gained about 2" inches. Yes I'm using a brass drift between the hammer and bolt. Way way too tight. The original one was a bit*^h to get out but not like this.

This is way to tight a fit. The pivot bolt shaft has 4 holes in it for grease to come through and those weren't cleaned up. I used a rat tail file to clean them up in anticipation of driving the bold through.

Any ideas here?
 
You need a machinist to open the bushing up a little.

Too tight.

Remove bushings and have them machined to fit your axle.

Bushing should have about .001 th interference fit with swing arm, so should take some hammering to fit.

And nothing more than a rubber mallet tight for the axle to fit inside the bushing.

Machinist will know how much to remove and do a nice straight clean job so you end up with a good fit.

Enlarging with a small hone could be done as well. This would be done with the bushing in the swing arm if you didn't want to remove them, but harder to clean out the grindings to end with a clean job. Suggest attaching a vacuum cleaner to the opposite end you are honing to remove grit or apply air pressure to the opposite end to blow the grit out. Send method works better than the first.

Do you add a grease fitting? Great for longevity although the one on the end of the bolt works as well.

You are looking for a tight fit, bushing to swing arm.
You are looking for a snug fit, bushing to pivot bolt.

Mine was tight enough to move freely after fully assembled but definitely not loose, up and down, and no movement side to side.

Good Luck
 
I will somewhat contradict Brian. I think removing the brass bushing will pretty much ruin them. Maybe i am wrong. I think I would try the home hone method. To me at this point you have nothing to loose with the bushings already installed, and the possibility of ruining them trying to take them out.
 
RacerDave, you are right the bushings will get beat up, but if he is going to a machinist anyway, that can easily be fixed.

I was going by what he wrote, "Bushing installed into the swing arm just fine", thinking they may come out petty easily.

Small hones are not terribly accurate and hard to find.

Good point though.
 
I thought his problem was fitment of #6 (pivot bolt) into #2 (steel inner swingarm bush).
If so, it should be a smooth sliding fit, with no slop.
79-Swingarm.jpg
 
He knows it now, but always test fit parts before assembly. Drift that thing back out of there. You have to, it is not designed to be a hammer in fit. I'll pile on and say about the third blow with no movement should have been the STOP NOW point. As suggested above there's a good chance some sort of chad is being driven in with the pivot shaft. Get it back out and see what's really happening, proceed from there. AFAICR the pivot shaft has always just twisted, slid in for me with maybe a few taps helping steady progress.
Getting old ones out? That's a different story.
 
Thanks for the info everyone.

The parts are from MikesXS. - per my order sheet fro Mikes - the parts list Part #27-1067 & 27-1068. I wouldn't think I would have to take a brand new part and take it to a machinist to have it worked on.

The length of the pivot bolt and diameter fit the frame perfectly. I trial fit it before.

Here are the two parts I'm talking about

Swingarm Pivot Bolt (Shaft)
https://www.mikesxs.net/product/27-1067.html

bushing
https://www.mikesxs.net/product/27-1068.html

The reason I posted this thread was that I thought something was odd about all of it. After I started this thread I went back to the old/original pivot bolt/bushing and the bolt slides through the bushing without issue.

I did debur the inside of the bushing The 4 holes that were drilled for grease to get through required this because they weren't cleaned up when the part arrived. But - the pivot bolt didn't fit into the bushing at all.

I'm going to have to grind down the old pivot bolt to use as a driver to drive the new pivot bolt out and check with Mikes to see whats up.
 
So I got it apart. Nothing gaulled/smashed or flattened.

So I pulled out the calipers and checked some ODs & IDs

Swing arm bolt diameter = .622
Original swing arm bolt tube ID: .630
New swing arm bolt tube ID: .622
 
I had the same issue with the bolt and tube purchased from Mikes. I honed mine until the bolt was a snug fit. I used a small flex hone and alot of wd40. Got it from the mac tools guy.
 
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