Aw Shooooooot! Rear Shock Mount Stripped Thread!

STRider said:
Appreciate that fundamentally this is an M8 bolt and its torque requirements are consistent with that spec.

23 N-m / 2.3 kg-m or 17 ft-lb​

To the uninitiated, it might be easy to assume some greater torque than this.
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Also note the reminder to apply MolyPaste on the load bearing surfaces...
I've seen/cursed over dry installed/corrosion welded shock bolts...
 
St-Gerard said:
Hi Taffy , first congrats on removing broken piece. One thing I would check is the hole in the final drive hasn't worn where the collar part of the bolt sits .
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Cheers on that. I thought about this too, as it looks a little 'shiny and bright':oops:. Question is, suppose it is a little 'polished', so what? What would I do? A shim? A washer? I dunno, what does anyone do when they've escaped an otherwise pain in the ars* fix?:):)
 
ST1100Y said:
Also note the reminder to apply MolyPaste on the load bearing surfaces...
I've seen/cursed over dry installed/corrosion welded shock bolts...
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Yep cheers, was aware of this but I don't remember doing it when I fitted the shock about a year or so ago. I assume it's top and bottom bolt, not just the bottom?
 
Ron said:
The screw part number for US bikes. Probably same for UK bikes. 90159-MG9-000

www.partsfish.com

1999 Honda ST1100AAC Rear Shock Absorber

Shop online for OEM Rear Shock Absorber parts that fit your 1999 Honda ST1100AAC, search all our OEM Parts or call at 800-964-1882
www.partsfish.com www.partsfish.com
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I'm taking this on trust, but it looks good to me. The part is on order and should be in my hands within a week. Best get my cleaning kit and maybe start on getting the fuel tank back in.:)
 

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  • Shock Mounting Bolt ST100AY.JPG
    Shock Mounting Bolt ST100AY.JPG
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I am betting that all fasteners will be very well lubed and torqued on this fine steed going forward. Thanks for the lesson and great ending.
 
St-Gerard said:
Hi Taffy , first congrats on removing broken piece. One thing I would check is the hole in the final drive hasn't worn where the collar part of the bolt sits .
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Taffy said:
Cheers on that. I thought about this too, as it looks a little 'shiny and bright':oops:. Question is, suppose it is a little 'polished', so what? What would I do? A shim? A washer? I dunno, what does anyone do when they've escaped an otherwise pain in the ars* fix?:):)
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@Taffy you're fine with the rear drive housing as is. The last photo in your post with photos of all the work you completed confirms this. They are very helpful for this crew. Thanks.

Think for a moment about how that bolt performs its function. The threaded portion of the bolt is really just to retain itself in the clevis of drive housing. It does not retain the shock by virtue of how it's torqued into place. It doesn't clamp the clevis or the shock eye in any way. There are no lateral, axial forces on the bolt, only radial forces from the shock eye, through the bolt to the clevis.

The countersunk surface where the shoulder of the bolt mates with the drive housing looks fine in your photo. Get a new bolt, apply a small amount of moly grease to the threads and the bearing surface of the bolt and torque to spec. None of the forces it encounters are in a direction which would induce it to loosen.

Take a look at the photo of the bolt I posted. It's just an M8-1.25 x 16mm flange bolt... but with a 35mm thick flange! Of course that flange also acts as the bearing surface for the lower shock eye, but again it doesn't clamp anything.
 
cjames431 said:
Don't use a heli-coil. They're junk. Use this repair instead
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I bought some Time Serts, and an installation kit some years back but haven't had the opportunity? to use them. A friend who shared my restoration mania told me about them. MUCH more durable than the helicoil. I'm supposing that having them at hand is a lot like taking an elephant gun hunting....you never see an elephant.
 
Hi Taffy, been meaning to write back sooner to explain why I suggested to check the fit of the shoulder to the housing too much wear and the bolt will be moving , which will sooner or later break the bolt. When you get the new bolt I would put it in backwards ( without the shock)and feel for any play. Looking at your pictures it looks in good shape .
 
STRider said:
There are no lateral, axial forces on the bolt.......
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.....but it can be subjected to axial stress if not torqued up correctly, which then can, as stated here....

St-Gerard said:
..... sooner or later break the bolt. . .
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And....

STRider said:
....... acts as the bearing surface for the lower shock eye.......
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....proper shoulder and torque also help ensure the pin won't back off while the shock rotates on the bearing surface while compressing/extending.
 
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