Author Topic: Help me ID this bolt  (Read 737 times)

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Offline EastSidinA4

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Help me ID this bolt
« on: March 31, 2010, 05:40:52 PM »
The red arrows point to the bolt that is leaking oil. It is on the right side of the bike (when sitting on the bike). There seems to me that there's 10 of them running across the bottom, but I only need to replace one.

My question is, can I just simply take that bolt & washer out and put a new one in (after I drain the oil first) without messing anything up inside? Because I dont know what it's attached to and it might be holding something inside that might drop if I take it out.
« Last Edit: March 31, 2010, 05:42:35 PM by EastSidinA4 »

Offline bistromath

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Re: Help me ID this bolt
« Reply #1 on: March 31, 2010, 05:57:58 PM »
That's one of the crankcase main bearing bolts. It bolts the top and bottom halves of the crankcase together right next to the main bearings. You can replace it for sure, but you might want to find out why it's leaking oil first. It's more than a little possible that you have a crack in the crankcase that's letting oil into that hole.

You also shouldn't have to let the oil out in order to replace it. In fact, if there's nothing wrong, there shouldn't be any oil in that hole at all. Are you sure that bolt is leaking oil, or is there an oil leak nearby that is running down to and dripping off of that bolt? Oil leaks can be very misleading.
'75 CB550F

Offline EastSidinA4

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Re: Help me ID this bolt
« Reply #2 on: March 31, 2010, 06:19:29 PM »
That makes sense. I'll check into it further. Thanks for the help!

Online Don R

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Re: Help me ID this bolt
« Reply #3 on: March 31, 2010, 08:57:21 PM »
My experience as a plumber says look further before you take action. the leak is almost always above the wet spot.
No matter how many times you paint over a shadow, it's still there.
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Offline ekpent

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Re: Help me ID this bolt
« Reply #4 on: March 31, 2010, 09:06:40 PM »
You plumbers and wet spots  ;D  ;D Not getting around my wife  :D

Offline steamnjn23

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Re: Help me ID this bolt
« Reply #5 on: March 31, 2010, 09:25:03 PM »
an old mechanic trick i have used is to use a timing light and aim it at the area you suspect of leaking.  the timing light will freeze the leak and you can watch it being formed.  use a fan for cooling also
1976 cb550