Honda-SOHC

SOHC.co.uk Forums => CB750 => Topic started by: roverboy on December 24, 2024, 01:07:32 PM

Title: brearing shells
Post by: roverboy on December 24, 2024, 01:07:32 PM
hi all at sohc hope you can help me regarding replaceing my crank and con rod bearing shells am i right in thinking as all the original shells have green coding that  its ok to order like for like also should i reuse the old crank bolts or are they torque to stretch type and also i normally use three bonds1215 sealer but would honda bond be better would appreciate your comments and tips kind regards john
Title: Re: brearing shells
Post by: Nurse Julie on December 24, 2024, 01:55:34 PM
Hi John.
Using all green shells in theory sounds great but that will only work if there is no wear on the crank shaft. You need to measure the current clearance with Plastiguage to see if they are all within spec still. Yes, you can use the existing crank bolts and Hondabond or similar is fine for the crank case halves and should be used very, very sparingly.
Out of interest, why do you think you need to change all the shells? Are they really pitted or scored?
Title: Re: brearing shells
Post by: archmill on December 24, 2024, 03:48:56 PM
Roverboy, a number of years ago I did a technical article for Practical Sportsbikes on this very subject I.E. how to measure your crank and which shells to buy.
Would you like a copy
Title: Re: brearing shells
Post by: McCabe-Thiele (Ted) on December 24, 2024, 03:49:41 PM
Presumably all five of your crank case code letters are the same e.g. A A A A A A for the mains shells, that's pretty lucky that you could see all the original bearing shell colours, presumably low mileage or shells have been replaced recently.

As Julie says crank measurement are ideal as you can check for any ovality,  you could use Plastigauge to check for wear against a single pair of new mains & new big end shells.
Title: Re: brearing shells
Post by: Laverda Dave on December 24, 2024, 10:31:17 PM
Roverboy, a number of years ago I did a technical article for Practical Sportsbikes on this very subject I.E. how to measure your crank and which shells to buy.
Would you like a copy

That would be a great article to put in the Aladdins Cave if you can please👍
Title: Re: brearing shells
Post by: archmill on December 24, 2024, 10:46:14 PM
How do I add to Aladins Cave ?
I have two articles, one on how to use Plastigage and one how to select shells
Title: Re: brearing shells
Post by: taysidedragon on December 24, 2024, 11:15:02 PM
How do I add to Aladins Cave ?
I have two articles, one on how to use Plastigage and one how to select shells

I think SteveD has to do it?
Title: Re: brearing shells
Post by: roverboy on December 25, 2024, 09:56:03 AM
hi all thanks for all your replies much appreciated not sure how i reply to each of you individually not good on computers  regards john
Title: Re: brearing shells
Post by: roverboy on December 26, 2024, 01:17:13 PM
Hi John.
Using all green shells in theory sounds great but that will only work if there is no wear on the crank shaft. You need to measure the current clearance with Plastiguage to see if they are all within spec still. Yes, you can use the existing crank bolts and Hondabond or similar is fine for the crank case halves and should be used very, very sparingly.
Out of interest, why do you think you need to change all the shells? Are they really pitted or scored?