honda305.com Forum

Vintage Honda Owners, Restorers, Riders and Admirers


305 oil seal leaks

Post Reply
hoodooman1
honda305.com Member
Posts: 2
Joined: Wed Oct 15, 2025 12:53 pm

305 oil seal leaks

Post by hoodooman1 » Mon Oct 20, 2025 8:23 am

Morning,
New guy here. I have inherited my father's 68 305 dream. I've done some work to get her up and running well, but the oil seals were leaking massively on the right side so I ordered a seal kit. Even after replacing all the right side cover seals, she's still weeping some. I haven't pulled the side cover off again to verify which one(s) are leaking, but they were all leaking previously. I'm pretty sure that the clutch pushrod has some wear in it and it may be the biggest culprit. Can anyone share some advice/opinions on how to approach this? I'd really love to completely seal this thing up. I replaced the seals for him about 20 years ago and they held up well for a long time.

User avatar
Tim Allman
honda305.com Member
Posts: 512
Joined: Tue Dec 02, 2014 9:25 am
Location: Guelph, Ontario, Canada

Re: 305 oil seal leaks

Post by Tim Allman » Mon Oct 20, 2025 9:25 am

It may well be the clutch pushrod. Pull it out and have a look. You will probably find that it has been worn down a bit at the seal. This can go on for a long time without leaking but leak it will at some point. The last time this happened to me I just replaced the seal and it continues to, well, seal. Given that both the pushrod and the rubber seal wear and that the rubber should wear faster than the steel, I'm guessing that the rod is not worn enough that replacing only the seal can't stop the oil. Yours appears to be beyond that point.

CMS has some NOS rods https://www.cmsnl.com/products/rod-clutch_22850259010/ for what seems a reasonable price but there are also others around.

hoodooman1
honda305.com Member
Posts: 2
Joined: Wed Oct 15, 2025 12:53 pm

Re: 305 oil seal leaks

Post by hoodooman1 » Tue Oct 21, 2025 10:12 am

Thanks for the info! Much appreciated.

Post Reply