[G.Jeffrey]

Do I need to completely tear down my engine on my 1980 CM400T to change the camshaft oil seal

 

[J-T]

Moved to SOHC engine section.

Perhaps you could be more specific as to what you want to change. Here's a parts fiche that may be helpful:

https://www.hondapartshouse.com/oemparts/l/hon/505416d7f870021c54bef48b/1980-cm400t-a-parts

 

[doode]

I don't recall this engine has a cam shaft seal... Do you mean the valve cover seal?
Number 8 here
https://www.hondapartshouse.com/oem...9747b87ef/cylinder-head-cover-camshaft-holder

If so, you just remove the 2 bolts and replace it.

 

[G.Jeffrey]

Correction I meant the crankshaft oil seal

 

[drydreamer]

From memory yes, engine out and strip down, but no need to remove the cylinder head. You have the flywheel extractor tool and clutch peg spanner ? From memory the crank seal has a raised lip that sits in a slot in the crankcase, to stop it from coming out.

 

[G.Jeffrey]

Where do I ge the clutch peg spanner tool I have the flywheel tool

 

[nigelrharris03]

That depends on where in the world you are. If you put you location in your avatar it would be easier to offer advice on obtaining parts.

 

[G.Jeffrey]

I am in Maryland USA

 

[longdistancerider]

The correct way of replacing the crankshaft oil seal requires splitting the case. You also have to drop the timing chain since the crankshaft has to be lifted up to slide one off and the other on.
There is a inner lip on the exterior of the seal that locks it in place in the case.
There is an alternative that carries an inherent risk. You can trim that lip off the seal and carefully drive it in to the same depth as the old one. The dangers here are that it gets driven in too far, driven in crooked and since these engine have positive crankcase pressure it may blow out. Removing the old seal is a real booger since that lip is there holding it. If you choose to go this route I would buy 2-3 seals at a time because the first one will not be right. Can't say I recommend this procedure but I did do it to finish the first tour

 

[G.Jeffrey]

Thank you for the imput I tried to replace the second way and it still leaks. So I think I am going to take it to the local vintage Honda motorcycle shop and have them install the seal the proper way