Honda-SOHC

SOHC.co.uk Forums => CB350/400 => Topic started by: Drew400 on April 29, 2014, 03:15:37 PM

Title: CB400/4 crankshaft bearings - refit or replace?
Post by: Drew400 on April 29, 2014, 03:15:37 PM

Hi all, my latest seeking of advice...

I have split the crankcase only for cleaning, it was running fine until then. All the innards are in tact and will be replaced (i.e. not taken sprockets off shafts, etc.). The crankshaft bearing shells all look fine to me and have been carefully labelled for refitting. Some people have said they will be fine to go back and others (like my Haynes manual) suggest they should be replaced. Maybe this is dependent upon the bike's post-rebuild life plan... it will be retired into occasional good weather use only; the bugger's had a hard life to date, or so it would seem, and now deserves a warm pasture!

Any conclusive thoughts from experts out there?

Thank you as usual.

D.

Title: Re: CB400/4 crankshaft bearings - refit or replace?
Post by: mickwinf on April 29, 2014, 05:00:30 PM

I am in the same position with my 500/4, and they are going back in, as long as they are not scratched or showing copper through the tin surface I think they are good to go.

Title: Re: CB400/4 crankshaft bearings - refit or replace?
Post by: Trigger on April 29, 2014, 06:08:28 PM

Change the sells. especially on anything high mileage and as Oddjob says, Chains, tensioner, damper rubbers ect ,ec. Also check all the rolling bearings and check out the oil pump. If you are in, you may as well. Rolling bearing can be matched and not expensive. 

Title: Re: CB400/4 crankshaft bearings - refit or replace?
Post by: Trigger on April 29, 2014, 06:57:48 PM

Yep, Your right Oddjob. I never give a price of a re-build until i have stripped it and had all the requirements from the customer.
Where's the pictures then??? 

Title: Re: CB400/4 crankshaft bearings - refit or replace?
Post by: Drew400 on April 29, 2014, 08:14:46 PM

Thanks all so far.

I'll sort some pictures ASAP (will be a few days). In the meantime, you have given me plenty of quality food for thought already!

Cheers, D.

Title: Re: CB400/4 crankshaft bearings - refit or replace?
Post by: Drew400 on May 10, 2014, 12:29:57 PM

As promised, here is a (typical) photo of one of 8 shells. What do you think?

Cheers,

D.

Title: Re: CB400/4 crankshaft bearings - refit or replace?
Post by: ka-ja on May 10, 2014, 12:47:06 PM

Hi,
     Looks fairly new to me, barely polished/worn.    Ken

Title: Re: CB400/4 crankshaft bearings - refit or replace?
Post by: Drew400 on May 10, 2014, 02:58:19 PM

Me too. Thanks for the second opinion. Cheers, D.

Title: Re: CB400/4 crankshaft bearings - refit or replace?
Post by: Captain Snakebite on May 29, 2014, 12:14:41 AM

Surface appearance is probably a good guesstimate guide, but if it was mine I'd be reaching for the Plastigauge to help with the decision.
Let us know how you go? :-)

Title: Re: CB400/4 crankshaft bearings - refit or replace?
Post by: Trigger on May 29, 2014, 08:27:33 AM

Need to see all of them Drew and photo,s which are vertical. The one in the picture has spotting and looks to be well worn but, i can't blow it up enough for a good look.
Just found a tool on my computer to blow your picture up more. I would not advise anyone to put that shell back in a engine. It is always to be safe than sorry.   

Title: Re: CB400/4 crankshaft bearings - refit or replace?
Post by: Drew400 on June 03, 2014, 03:02:13 PM

Thanks again all. D.

Title: Re: CB400/4 crankshaft bearings - refit or replace?
Post by: Clem2112 on June 03, 2014, 06:52:21 PM

Second that !

Title: Re: CB400/4 crankshaft bearings - refit or replace?
Post by: Bitsa (Ralph Wright - RIP) on June 03, 2014, 06:55:40 PM

Third that along with all chains and tensioners
Cheers
Bitsa

Title: Re: CB400/4 crankshaft bearings - refit or replace?
Post by: Trigger on June 03, 2014, 09:48:02 PM

Oddjob is right on that one. CB400 shells are still cheap and ready available. Twice the price from ten years ago. CB500/550 shells are becoming hard to find. I can only find Green and Brown and i am two Black ones short for a re-build. I have a way around this by white metaling them but, this has to be done right and not cheap.

Title: Re: CB400/4 crankshaft bearings - refit or replace?
Post by: Drew400 on June 09, 2014, 03:51:23 PM

Thanks all.

Bullet bitten and savings started.

You're all correct... the thought of stripping it all down again after rebuilding it, don't appeal much!

Cheers, D.