Author Topic: Crankshaft bearings and grease  (Read 1263 times)

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Offline jollygreengiant

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Crankshaft bearings and grease
« on: August 12, 2012, 06:49:40 PM »
Hi
I'm doing a complete restoration of a 1977 CB 750 K7, and I'm at a point where I'm putting together crankshaft, countershaft, chains etc and, in a day or two, reassembling the crankcase halves. From what I understand when reading the manual, I'm supposed to apply a thin coating of molybdenum disulfide grease to the crankshaft bearings. Are they not fed with oil? Strangely enough it also looks from the illustrations as if the grease is supposed to be applied to the bearings' backsides. Might this be just to alleviate installation of new bearings? Anyone have an explanation?
Tor, Norway

Offline Greggo

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Re: Crankshaft bearings and grease
« Reply #1 on: August 12, 2012, 08:02:13 PM »
The application of assembly lube is necessary to prevent metal contact upon startup before adequate lubrication is supplied.

Online Don R

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Re: Crankshaft bearings and grease
« Reply #2 on: August 12, 2012, 08:50:12 PM »
I wouldn't grease the backsides. Can't believe that is in a manual. If so it may be a motorcycle only thing. Anyone else ever do that? I would buy an engine assembly lube, there are some very good ones available.
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Offline dave500

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Re: Crankshaft bearings and grease
« Reply #3 on: August 13, 2012, 12:40:07 AM »
the backside must be clean and dry.

Offline trueblue

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Re: Crankshaft bearings and grease
« Reply #4 on: August 13, 2012, 03:06:57 AM »
the backside must be clean and dry.
But what about the bearing ???
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Offline jollygreengiant

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Re: Crankshaft bearings and grease
« Reply #5 on: August 13, 2012, 06:56:27 AM »
Thanks for all responses, that cleared things up  :D Now, back to work!  ;D

Offline dave500

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Re: Crankshaft bearings and grease
« Reply #6 on: August 13, 2012, 12:51:19 PM »
the backside must be clean and dry.
But what about the bearing ???

caution when farting!

Online Don R

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Re: Crankshaft bearings and grease
« Reply #7 on: August 13, 2012, 01:00:01 PM »
Never trust a fart. So to sum it up, assembly lube on the crank and bearing, back side dry.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
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