Conrod bolts
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- Old Fogey
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Conrod bolts
Info needed from anyone that has had the complete engine stripped.
Are the conrod bolts safe to reuse? Has anyone had problems after doing so?
The nuts will be renewed as a matter of good practice.
Also on the 76 crank it would appear to have been reground at some time.
The con rod bearings are marked 1.0mm and the journals are 39mm instead of 40mm; the mains ave shells marked 0.5mm and the journals are 47.5mm instead of 48mm. The shells have the mark AE which was a company that made bearings and pistons etc. for the aftermarket.
I believe they are now part of Federal Mogul.
Anyone have info on this?
Are the conrod bolts safe to reuse? Has anyone had problems after doing so?
The nuts will be renewed as a matter of good practice.
Also on the 76 crank it would appear to have been reground at some time.
The con rod bearings are marked 1.0mm and the journals are 39mm instead of 40mm; the mains ave shells marked 0.5mm and the journals are 47.5mm instead of 48mm. The shells have the mark AE which was a company that made bearings and pistons etc. for the aftermarket.
I believe they are now part of Federal Mogul.
Anyone have info on this?
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- CYBORG
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- Whiskerfish
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There are not many guys around that have split cases.
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"Yea I do dance awkwardly, and I am having more fun than you" Taylor Swift
2008 GL1800 IIIA "TH3DOG"
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1975 Naked Noisy and Nasty in town bike
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I have slipt cases and rebuilt. You must remove the rods from the crank to do so. The bearing are color coded. You have 2 codes, 1 on the case and 1 on the crank. You match the 2 to get the color code bearings for the mains. Then the crank and rod for the color for each journal. You can also measure and match. The manual gives you both options. I have always reused the rods and thier bolts with no problems. After 3 case splits and many miles I have no negatives to report.
I think the hardest part is putting the cases back together. Honda has some special tools for it but if you understand what is needed you can get by without them. Do not touch the bearing surface with you hands, rubber gloves are good here.
You can use plastiguage to check the clearances but it is only needed if you reuse a bearing. I never do that.
I think the hardest part is putting the cases back together. Honda has some special tools for it but if you understand what is needed you can get by without them. Do not touch the bearing surface with you hands, rubber gloves are good here.
You can use plastiguage to check the clearances but it is only needed if you reuse a bearing. I never do that.
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- Old Fogey
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Thanks for the reply guys.
Good news on the bolts.
The main reason for posting about the bearings is that there is NO colour coding on any of them, which is what makes me think they are aftermarket bearings.
I hope to get time to get the 79 crank out of the cases tomorrow; hopefully theres no surprises in there.
Still puzzling over the bearing selection as it appears Honda think wear only takes place on the shells. Fairly obvious that both the crank and shells wear.
Plastigauge will tell you how much clearance there is, the colour code tells you what the original thickness of the shells for that journal were, but without actually measuring the crank I can't see how you know which new size to use.
Guess I'm just thick
Good news on the bolts.
The main reason for posting about the bearings is that there is NO colour coding on any of them, which is what makes me think they are aftermarket bearings.
I hope to get time to get the 79 crank out of the cases tomorrow; hopefully theres no surprises in there.
Still puzzling over the bearing selection as it appears Honda think wear only takes place on the shells. Fairly obvious that both the crank and shells wear.
Plastigauge will tell you how much clearance there is, the colour code tells you what the original thickness of the shells for that journal were, but without actually measuring the crank I can't see how you know which new size to use.
Guess I'm just thick

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- mooseheadm5
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Most of the wear takes place on the bearings- they are designed that way.
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- starket
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Most of the wear occurs on the shells as they are a much softer material. Usually a crank only needs to be turned if there is a bearing failure and the harder part of the shell hits the crank.Old Fogey wrote:Still puzzling over the bearing selection as it appears Honda think wear only takes place on the shells.
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If you are using bearing without color codes I would definately use plastiguage to know what clearance there is. Too much clearance or too little clearance can cause a problem sometimes right away sometimes much later on. I do not know of a bearing set from Honda that does not have a color code on it. That is something I would aviod, seen some horrific damage from non OEM parts.
As far as the wear on them, and not the crank, rods or cases, comes down to preventative maintenance. Oil and filter changes are the first and foremost. Oil pressure (oil pump care) is another. Proper warm ups are also included. Cranks rods and cases can wear, seen all of those but usually because of neglect.
Because the oil can not be compressed there is a thin layer between all of the metal surfaces. In theroy the metals never touch. Oil contaminates, lack of oil pressure, and excessive wear are the cause of the contact where not wanted.
As far as the wear on them, and not the crank, rods or cases, comes down to preventative maintenance. Oil and filter changes are the first and foremost. Oil pressure (oil pump care) is another. Proper warm ups are also included. Cranks rods and cases can wear, seen all of those but usually because of neglect.
Because the oil can not be compressed there is a thin layer between all of the metal surfaces. In theroy the metals never touch. Oil contaminates, lack of oil pressure, and excessive wear are the cause of the contact where not wanted.
May The Fours Be With You.
CB77 1965 First Bike
GL1000 1975 "Puffy" damaged in accident
CB750F2 1978
GL1000 1976 "Puffy Too"
CB77 1965 First Bike
GL1000 1975 "Puffy" damaged in accident
CB750F2 1978
GL1000 1976 "Puffy Too"
- Old Fogey
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Well, searches on the Net have turned up precisely nothing on this.puffy75 wrote:If you are using bearing without color codes I would definately use plastiguage to know what clearance there is. Too much clearance or too little clearance can cause a problem sometimes right away sometimes much later on.
From the condition of the bearing shell surfaces I don't even need to Plastigauge them, they need replacing
I do not know of a bearing set from Honda that does not have a color code on it. That is something I would aviod, seen some horrific damage from non OEM parts.
These shells cannot be OEM honda ones according to the manual since the sizes are all wrong
As far as the wear on them, and not the crank, rods or cases, comes down to preventative maintenance. Oil and filter changes are the first and foremost. Oil pressure (oil pump care) is another. Proper warm ups are also included. Cranks rods and cases can wear, seen all of those but usually because of neglect.
There is definately signs of a little waer on the crank but not much
Because the oil can not be compressed there is a thin layer between all of the metal surfaces. In theroy the metals never touch. Oil contaminates, lack of oil pressure, and excessive wear are the cause of the contact where not wanted.
I'm guessing that that crank is now history!
"Impossible Is Just a Level of Difficulty!..."
If I'd wanted you to understand, I would have explained it better! (Johann Cruyff)
I’d give my right arm to be ambidextrous!
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I’d give my right arm to be ambidextrous!

- CYBORG
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often there is a transfer from the bearing to the crank, that makes the crank look like it is scared or pitted. often a little crocus cloth will clean it up. just mic it after to ck specs. someone may have already messed with it before you got it. i'd shine it up and take a reading and go from there
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- mooseheadm5
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If your crank journals are undersized, just go buy bearings to match. You need the original outer diameter of the shells and the actual diameter of the crank journals, then subtract the proper oil clearance and you will have the bearing dimensions you need. Sounds like you need to special order anyway.
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- Old Fogey
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Thanks Moose. I know the how of measuring them up but not the where of how to get them. I guess the engine shop I'm taking the block to may be able to help with that but........mooseheadm5 wrote:If your crank journals are undersized, just go buy bearings to match. You need the original outer diameter of the shells and the actual diameter of the crank journals, then subtract the proper oil clearance and you will have the bearing dimensions you need.
Well, not yet I don't. Two 79 cranks to check out first, one of which (supposedly) has less than 20K on it. I'd much prefer to get back to standard Honda sizes.mooseheadm5 wrote:Sounds like you need to special order anyway.
Before anyone jumps on me; yes, I know the timing marks will need to be altered if I use one of them.
"Impossible Is Just a Level of Difficulty!..."
If I'd wanted you to understand, I would have explained it better! (Johann Cruyff)
I’d give my right arm to be ambidextrous!
If I'd wanted you to understand, I would have explained it better! (Johann Cruyff)
I’d give my right arm to be ambidextrous!

- Old Fogey
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I'm going to continue this in my restoration thread as it seems to be the right place for an ongoing saga of woe and misery
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"Impossible Is Just a Level of Difficulty!..."
If I'd wanted you to understand, I would have explained it better! (Johann Cruyff)
I’d give my right arm to be ambidextrous!
If I'd wanted you to understand, I would have explained it better! (Johann Cruyff)
I’d give my right arm to be ambidextrous!

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