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Discussion Starter · #1 ·
Hello there,

Apologies in advance as I realize there are a lot of posts regarding leaks on older CB's. However I am relatively new to biking and want to make sure I'm getting the correct parts! A lot of the older posts links for photo's/parts are dead.

I have a leak coming from the left crank case and after some research I'm fairly confident it's the shifter oil seal and/or the seal on my clutch lift rod. Photo's below are of when I first removed the left rear crank cover.

Parked for 5 minutes after a 15 minute ride......

Oil Leak.jpg

Left Rear Crank Cover removed (You can see how filthy it is in there)

Left Crank FULL DIRTY.jpg

Up close

Left Crank ZOOM DIRTY.jpg

After cleaning I believe I need to replace the Clutch Lift Rod Seal

InkedClutch Rod Seal CLEAN_EDIT.jpg

As well as the Shifter Oil Seal

InkedShift Seal CLEAN_EDIT.jpg

Now for my questions :D

1. Can anyone confirm the names/part number to these seals?
2. Can anyone confirm where to order these?

I have had trouble getting an exact name or part number and want to make sure I'm ordering the correct replacement pieces.

Any pointers/advice/comments are greatly appreciated!

*** If this is posted in the wrong place please let me know and I will remove it ***


13,085 Posts I realize there are a lot of posts regarding leaks on older CB's
First - great that you put the bike model in your subject line, that's always both helpful and necessary to answer questions. But, realize that there are many different "CBs" in Honda's lineup from those days, so a blanket term about "CBs" is only relevant to which CB we're talking about - and many models, whether CB or CL (and those were usually so close to the same that all the engine parts were often, if not always, identical) all had similar leaks for the same reasons. Just FYI for the future.

That said, it does look like your clutch rod seal leaking... the dead giveaway (unless you cleaned the area prior to the picture) is the clean area below the seal, a sure sign oil flowing by has washed away [previous chain lube and the dirt that it attracts. Don't be too concerned about how grimy it is under the front sprocket cover, it will look that way again in a month after you clean the area. The other tip that it's your clutch rod seal is the fact that the seal isn't in the crankcase all the way and someone used a mass amount of RTV to either seal it or assist in its installation, both of which are not good. You don't want RTV floating around in your oil passages, it can cause blockage of oil flow and result in massive damage.

there are many places to get these seals -, DCC as mentioned above, David Silver Spares, eBay from the right seller, Common Motor Collective... but the first thing you can always do to help yourself is go to either or Western Honda and look up the proper part number to do your own search (and keep those addresses, you'll be looking up more stuff in the future). My preference for seals and many other things for our vintage bikes is, as their prices are usually better than most and you rarely have an issues with their products and service. So, as I just mentioned - take a look at this price compared to the link above for the same seal from DCC

here's the correct seal for the shift shaft

Edit: I've bought a pile of stuff from 4into1, as well as many others here, and 2 complete seal kits for my 450 build were among the many things from there... so I can attest to their quality as well as a decent price

854 Posts
Wow, yours is pristine compared to what that area looked like when I put on a new chain last week. I think I dug out a couple lbs of filthy grease and rust from mine.
There are lots of smart helpful folks here that will get your leak sorted!
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