79 honda cx500 final drive leak

Hi guys I'm hoping to find someone on here who can help me. My brother passed away and left me his 79 honda cx500 rat rod I noticed the final drive was leaking out of the very top. Is this just a simple seal or do i have a bigger issue? Will attach pic. Thanks in advance. I'll also attach a pic of the bike just because.

 

If may have a bunch of moisture that has foamed the diff fluid or the actual vent has failed. Had a V45 Magna in the shop last year did the same thing and had to replace the vent. The year of the bike is important because some years you can’t get the vent and the later one is available but is not exactly the same. It can be installed only if you drill the case to the new size. Look up the part number at
hondapartsnation.com
The last 3 numbers in the part number will tell the story
Let me know
RB

 

Thank you very much I will look that up right away. Is their a way to check it to see if it is bad? Do I need any specialty tools to replace it?

 

Empty the oil and put new stuff in and put some miles on it to see if problem persists. It’s factory pressed in with epoxy.
You will have to do the same. Iirc the original one was 10 mm hole and new vent was 11mm I drilled it to 13/32 for a tight fit and marine epoxy. Never mind I had a closer look at the picture and your cx500 looks to be a bolt in one. And just looked up the part and is no longer available. And it’s only used on 79-82 cx500’s

 

Yes it is a bolt in one this is a 79 cx500 custom. I'm going to clean it up and like you said change the oil and see if it's ok, if it isnt could I have one made? If not I'll probably just have to replace the final drive right? Hopefully they still make those for this bike.