Snapped Shock mount bolt on Swing Arm
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Tourer
Joined: Oct 2005
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Snapped Shock mount bolt on Swing Arm
A few weeks ago I was heading to the gym on my lunch break and realized my air-ride was not working. That morning I lowered my Fatboy all the way down when I parked at the office and then it got stuck in the down position. With only an hour lunch break I didn't want to fuss with it and decided to just ride to the gym all the way low-riding. Not a good idea. I hit a small pot hole at 65mph and I heard something snap. It was the right shoulder bolt that mounts the shock to the swing arm.
This weekend I started to remove everything necessary to remove swing arm because the sheared bolt can not be removed without removing the swing arm. Prior to removing the broken bolt I soak it with WD-40 and let it sit over night. Tomorrow I'll start to drill; first a small hole, and then a larger one until I get one big enough to use the extractor.
I'm posting this up here because I have read about how a few people have broke the same bolt but no one has documented the process. If anyone has already done this and can add to the thread please do. I'll using an extractor kit from Sears seen in the last picture. More later...
This weekend I started to remove everything necessary to remove swing arm because the sheared bolt can not be removed without removing the swing arm. Prior to removing the broken bolt I soak it with WD-40 and let it sit over night. Tomorrow I'll start to drill; first a small hole, and then a larger one until I get one big enough to use the extractor.
I'm posting this up here because I have read about how a few people have broke the same bolt but no one has documented the process. If anyone has already done this and can add to the thread please do. I'll using an extractor kit from Sears seen in the last picture. More later...
Advanced
Joined: Mar 2013
Posts: 73
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From: MA
That sucks !!!! At least you can take the swing arm off and have room to work. Just drill it slow and take your time, plenty of lube. I've drilled out a million bolts in cylinder heads and the best thing I can tell you is once the extractor bites, don't force it. If you break the extractor you may just be buying a swing arm!
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Tourer
Joined: Oct 2005
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After center punching the bolt shaft I used a very small drill bit to make the center punch more pronounce before moving to the next drill bit. Starting with a small bit and then moving to the next size up, I made the hole 3/4 deep. I changed bits four times ending with 15/64". Using a hammer I tapped the #3 extractor, which is a little thicker then 1/4" at the thickest point, into the hole. I then used an adjustable wrench to turn the shaft out. The extractor worked like a charm. I used the hammer and wrench method rather then mounting the extractor to a drill because it had less chance of slipping. IMHO
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Tourer
Joined: Oct 2005
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Replacement OEM HD shoulder bolt are listed as # 4079, 4074 & 6724.
From what I understand #4079 is not chrome, #4079 is chrome, and 6724 is the washer. I have been looking for a stronger then OEM replacement and was referred to Diamond Engineering who responded with the following: "We currently offer a stainless shock bolt but it is not stronger than the OE bolt. This part is out of stock also. We are seeing if we can fit a 12 point flange bolt for this application. If we can it will be made from UGIMA 630 and heat treated to 180,000psi tensile (20% stronger than Grade 8). The new part should be in production by July as long as fitment works out"
I will be replacing the bolt with an OEM one until I find something better. Meanwhile, since I have the bike apart I will be playing with some Plasti-Dip parts...
From what I understand #4079 is not chrome, #4079 is chrome, and 6724 is the washer. I have been looking for a stronger then OEM replacement and was referred to Diamond Engineering who responded with the following: "We currently offer a stainless shock bolt but it is not stronger than the OE bolt. This part is out of stock also. We are seeing if we can fit a 12 point flange bolt for this application. If we can it will be made from UGIMA 630 and heat treated to 180,000psi tensile (20% stronger than Grade 8). The new part should be in production by July as long as fitment works out"
I will be replacing the bolt with an OEM one until I find something better. Meanwhile, since I have the bike apart I will be playing with some Plasti-Dip parts...
Road Warrior
Joined: Nov 2011
Posts: 1,397
Likes: 403
From: Australia
Try contacting a fastener specialist. Im sure they'd be able to supply something high-tensile that's suitable. They should stock Grade 8 bolts.
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Road Warrior
Joined: Mar 2008
Posts: 1,465
Likes: 3
From: Montclair, CA.
Another screw extractor which IMHO is better then the EZ out type of screw extractor is the Alden Grabit.
It has a built in drill bit and screw extractor all in one unit and you do not need to drill as deep as the EZ out and are less prone to breakage/snapping off as the EZ out.
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