Author Topic: Rear Engine Hanger Bolt (CB500F)  (Read 493 times)

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Offline DurangoCB

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Rear Engine Hanger Bolt (CB500F)
« on: May 26, 2018, 06:04:32 PM »
The lower rear engine hanger bolt on my '71 CB500 is bent.  (Pic below.)

The PO removed the side stand in order to accommodate a 4:2 exhaust and retrofitted another kickstand to the bike, which they mounted to the left side foot peg.  And which resulted in the bolt being bent.  I don't know if this is the original bolt and just happened to have enough extra length to accommodate the kickstand or if the PO had the original bolt replaced. 

The bolt I have is 360mm long, 12M, and the last 20-22 mm on each end are threaded.   

1.  Is that the stock bolt?

2.  Is it worth straightening?

3.  What are the chances of finding a replacement at BoltDepot.com or similar? 
1971 CB500 Four- current project http://forums.sohc4.net/index.php/topic,170622.0.html
1978 CX500- next in line

Offline DurangoCB

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Re: Rear Engine Hanger Bolt (CB500F)
« Reply #1 on: May 26, 2018, 07:20:07 PM »
Disregard- good old Mercury 4 vise.  Straightened the hanger out faster than green grass through a goose. 
1971 CB500 Four- current project http://forums.sohc4.net/index.php/topic,170622.0.html
1978 CX500- next in line

Offline calj737

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Re: Rear Engine Hanger Bolt (CB500F)
« Reply #2 on: May 27, 2018, 03:01:11 AM »
Disregard- good old Mercury 4 vise.  Straightened the hanger out faster than green grass through a goose.
If you bent it cold, expect it to be very fatigued, and likely to bend again. If you use heat, you can bend it more easily, BUT, let it cool normally to avoid making it brittle.

While you have it out, chuck it up in a drill, spin it, and clean it with steel wool/scotchbrite/emory or such to remove as much corrosion as you can. Then oil it before you shove it back thru the case. These get "stuck" often due to the stock bolt rusting and/or creating galvanic corrosion between the stock carbon bolt and the aluminum cases. They can be a PITA to remove and install.
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline DurangoCB

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Re: Rear Engine Hanger Bolt (CB500F)
« Reply #3 on: May 27, 2018, 07:29:18 AM »
I used heat but only have a propane torch and wasn't able to get it red hot because I knew the heat would transfer down to the PVC.  There was galvanic corrosion, which I removed a while back.  That bolt took me a while to get out. 
1971 CB500 Four- current project http://forums.sohc4.net/index.php/topic,170622.0.html
1978 CX500- next in line

Offline calj737

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Re: Rear Engine Hanger Bolt (CB500F)
« Reply #4 on: May 27, 2018, 09:54:21 AM »
So before you reinstall it, spray some Aluminum wheel cleaner into the holes in the case, and work the upper hangar bolt (which is 10mm) thru the passage with a cotton T shirt scrap to help scrape the gunk out. It will make the 12mm install more easily.

Propane was fine-
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis