How to.... disassamble the engine cases with clutch in place

jensen · Post by **jensen** » Tue Apr 24, 2012 2:00 am

Hi,

Last night I was disassembling an C77 engine, but the crank nut wouldn't come loose (in a normal way). Since I have no air powered tools in my garage to loosen it, and using a chisel is not my style, I tried to disassemble as far as possible without taking the nut off.

Because the clutch is attached with the chain to the primary sprocket, and the chain cannot be removed without removing the clutch or primary sprocket I thought I was stuck on methods.

I tried to split the cases without taking the crank nut and clutch off, and guess what ? it can be done. First remove the 10 mm bolt that keeps the 'shift drum stopper guide (p/n 24440-259-000) from the upper case (it can be reached without getting the clutch off).

While you split the case push the gear shift arm gently to the clutch, and the cases will split with everything in it. I already disassembled the cylinder and head, but that ain't necessary either. The only thing you have to do is keeping the crank and both shafts into the upper case while splitting.

Maybe you all knew this method already, I didn't, so that's why I described it.

This way I can take the crank out and take it to a guy who has the right air tools to get it loose without taking the whole engine with me.

For those who want to inspect the crank, shift mechanisms, or the counter shaft issue's this method saves work and time.

Jensen

mcconnellfrance · Post by **mcconnellfrance** » Sat Apr 11, 2015 9:54 am

Jensen,

Today, I have been trying to split the crankcases on my 1965 CB77 motor. I see that you have managed to do it without taking the clutch off and I am trying that as well.
However, I am stuck to break the sealant bond between the two cases. I have tried some gentle persuasion with a wooden block and mallet but they will not split so far.
Any tips for slitting the cases without resorting to brutal mishandling?

Also from your useful picture, I see that there should be a tab washer to lock the crankshaft nut. It is missing on mine and the nut is fairly damaged. I may have to take the nut off after all and then the clutch removal is only a step away!

Thanks

Gordon

cknight · Post by **cknight** » Sat Apr 11, 2015 11:01 am

Make sure that the two nuts on the top case that attach the valley cover bracket are also removed. Brutality should not be required.. Regards, Chase

G-Man · Post by **G-Man** » Sat Apr 11, 2015 11:45 am

There are quite a few M6 bolts lurking in dark corners, too.

+1 on the no-force comment, too!

G

mcconnellfrance · Post by **mcconnellfrance** » Sat Apr 11, 2015 2:44 pm

Thanks guys. Your support is great. I did forget the two nuts on the upper crankcase! Now it is free and I will split the cases tomorrow. Thanks again for your help.

Gordon