Need Help with Drive Sprocket Shaft Seal

[RodneyCB750K1979]

I removed the shaft seal, ending up totally destroying it.  I have the new seal and attempted to drive it in using a large diameter pipe but it wouldn't go inside the housing. Special tool needed?

  

[RodneyCB750K1979]

I am tending to believe the main shaft seal was intended to be installed with the crankcase split apart.  Has anyone run into this before?  I'm going to a bearing supply store tomorrow with housing and shaft dimensions and try to size a seal that can be installed from the outside.  

[shinyribs]

I've never done one on a DOHC. On my SOHC's both of them I replaced from the outside. No splitting the cases or whatever. I did have to get them lined up just perfect,though. They really go in tight in order to seal. A thin coating of grease helps them go in easier. You could also use a super thin coating of silicone since it would help seal any leaks that might try to crop up,but I'd be very,very careful to make sure no silicone made it's way into the engine.

[TOOLS1]

Whenever I install a seal, I smear a very thin layer of silicone on the seal. This will make it slide right in.
TOOLS

[seestheday]

Maybe ask on the CB750C site? They will likely know.

[TOOLS1]

seestheday wrote

Maybe ask on the CB750C site? They will likely know.

What's up with you and that CB750C site? You trying to recruit for them, or something?
TOOLS

[seestheday]

Sorry, I'll stop.  Didn't mean to offend.  I was just trying to help.  From the answers given it seemed that both you and Shiney had done this on SOHC bikes but not DOHC bikes, but I could easily be mistaken.  This may be a case where the SOHC & DOHC bikes differ so I thought a DOHC only forum might be helpful.

For what it's worth, I'm not recruiting for them.  I spend way more time here and find this place much nicer to hang around.  I just want to make sure that other DOHC owners know about the resources that are there.  The C site has some super knowledgeable DOHC people that have answers for very specific DOHC questions.  

The 1100F site has a ton of performance information for the DOHC bikes, but it is even less friendly than the C site.  They are honestly downright hostile to non F owners.  They are pretty explicit about ignoring non supersport questions: http://www.cb1100f.net/modules.php?name=Forums&file=viewtopic&t=2450
(hopefully you don't need a login to see that.  If not, don't bother unless you own a DOHC supersport because it's just a thread where they basically say everyone else is not welcome on that forum).

Even though its so unfriendly, it's still VERY valuable for those looking to make performance gains on any DOHC bikes - as long as you don't expect to get any answers for questions you ask.

[RodneyCB750K1979]

I'm not going to do this half-assed using a different seal without the inner lip. This would make the job easier, but after going this far into my restoration, I'm going ahead and split the case and replace all the seals.  Your thoughts and prayers are appreciated as I embark on this adventure.

[shinyribs]

Good luck Rodney. I'm sure you'll do just fine.

Sees',gather all the info you can and bring back here. This site admittedly does have more info for the SOHC bikes,but we need all the DOHC we can get,too. You can be our DOHC Ambassador

Gain knowledge-share it here

[Dmairs]

Hey just wondering how you got that seal out and where your bought the new one i have a 1979 honda cb750 thanks