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71 CB 350

Hey guys, taking care of an oil leak on the clutch pushrod seal (the seal 40+ year old seal had actually became unseated and oil was POURING out of the bike - good thing I noticed it before I seized the bottom end).

Anyway, it probably doesn't matter, but do I put a thin film of oil around the new seal when I install it, to aid in installing it? I'm concerned that if I do that it might not seal as effectively and eventually un-seat itself again (and maybe next time I won't notice the oil pouring out of it and I will seize the bearings).

Any recommendations?

clutch seal.JPG
 

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As you've found out that seal gets pushed out. Seals are made to be installed dry on their mating surfaces.

On the bike my method is to pull the rod and make sure it is straight as a bent rod will cause all sorts of issues. Pull the seal and clean the case where the seal is going to be sitting. You can use brake clean etc. I then put a thin film of Honda Bond onto the case edges and a thin coat onto the edge of the seal. You need to work quickly as the honda bond sets quickly. Drive the seal in flush and leave the roll of honda bond in place. Let it set up for a few minutes. The honda bond will help keep the seal in place ... that's my theory and it's worked for me so far.

Once the seal is in lube the seal around the rod and carefully insert the rod.
 

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Oh and take the chain sprocket off to do the install .... a large socket works well. I flip the socket so the flat is on the seal then put an extension into the socket and hit the extension with a small dead blow hammer.
 

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I made a guard to keep the seal in my 450 after seeing member doode make one for his 350. I attached the top of it to the left neutral switch screw hole with a slightly longer bolt and located the other end between the lower front screw boss for the front sprocket cover and the crankcase to keep it from moving. I figured that the material I made it from (one side of a piece of aluminum square tubing) was strong enough that the seal can't bend it with what little oil pressure these things have, plus it's held by a bolt with flat washer at the top as opposed to the JIS pan screw previously there on the neutral switch. Here's mine (zoom in on the sprocket area)

https://www.hondatwins.net/forums/attachments/262150d1533388329-cl450-project-reboot-street-legal-time-20180803_191040.jpg

I also noticed on 76TWIN's 500T that there seems to be a "case protector" added by Honda later. #2 here

https://images.cmsnl.com/img/partslists/honda-cb500t-twin-dohc-1976-usa-left-crankcase-cover_bighu0233e5009_ed16.gif

Pretty sure from what I saw in one of his pictures that the clutch rod goes through it. Not sure if that was the intent, but there have been many clutch rod seals pop out over the years and I'm sure Honda was aware of it
 

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Make sure the breather tube on the top of the engine is clear to vent excess pressure.
 

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Lots of us apply a very LIGHT coating of Honda Bond on the seal to give it a little more grip than a plain dry surface but your choice.
But do NOT lubricate it.
That will just make it pop out easier.
 

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Thank you for this good information peoples :) I have a new push rod and seal to install in my 1976 CB360T. Do i need to remove the right side case to remove the clutch lifter rod? The information I have seen so far indicates the rod will just pull out the left side...but I have tried pulling it with out success.
The little ball bearing has "welded" itself to the end of the rod...apparently there was no grease in the cup of the lever the the ball sits in.

Thank You in advance
 

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Yes, the clutch rod just slides out After the seal replacement, no need to pull the clutch cover. Make sure the rod is clean and lubed a little so it slides back into the seal smoothly
 

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Yes, the clutch rod just slides out After the seal replacement, no need to pull the clutch cover. Make sure the rod is clean and lubed a little so it slides back into the seal smoothly
Thank You... I will go try again right now. I have tried a couple times now to pull the rod out. I even attached vise grips to it and tapped on them to pull the rod out with no success. I have not pulled the seal out yet though, does the seal help hold it in?
 

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The rod should not be stuck in the trans like that... the seal does not help retain the rod, it should be free to move in and out of the seal when the front sprocket cover is off. If you can't pull the rod out with your fingers, something else is wrong and you'll need to pull the clutch cover (right crankcase cover) after all to find out what is going on. Once the clutch cover is off, you'll need to remove the 4 clutch spring bolts, the springs and the pressure plate and then look at the clutch lifter slipped into the end of the mainshaft - the rod pushes the back of it and correspondingly pushes the pressure plate

#12 (the rod) pushes #11 into the pressure plate #8

https://images.cmsnl.com/img/partslists/honda-cb350k3-super-sport-1971-usa-clutch_bighu0028e4008_5795.gif
 

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Like Tom says, you need to get into the clutch and find out the problem. If #11 is somehow stuck to the end of the rod the rod will be turning all the time, that will shorten the life of the seal quite a bit.
 
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