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CVO Technical => Drive Train => Topic started by: johnmowcop on June 30, 2023, 04:30:38 AM

Title: M8 transmission breather kit
Post by: johnmowcop on June 30, 2023, 04:30:38 AM
My Harley FLHTK, is suffering oil migration from g/box into primary chain case. The dealer says that is not covered by my extended warranty. He says I need a breather kit fitting at a cost of £400 or thereabouts. I intend to do this myself, are there options available, if so which is the best. Your advice would be much appreciated.
Regards
JohnT
Title: Re: M8 transmission breather kit
Post by: KGB on June 30, 2023, 06:51:59 AM
I would recommend the vent kit from Harley Davidson, I know there are other fixes out there, but this one worked on my bike, I noticed mine had transferred 8 OZ at the first oil change, took it to dealer and they installed the vent kit under warranty, I'm assuming your bike is older than 2 years. It doesn't look very difficult to do, lots of videos on it.

Good luck
Title: Re: M8 transmission breather kit
Post by: HOGMIKE on June 30, 2023, 08:44:36 AM
The HD kit was installed on my 2019 cvo as soon as they rolled it out.

Mine also had major transfer since new. The dealer was just following HD’s procedure
Unfortunately the damage was already done to my trans and it broke just after the 2 yr warranty was over so HD would not cover the damage.

Do the kit yourself, it’s not that difficult. The kit is $$$$ but includes gasket and good instructions.

JMHO
Title: Re: M8 transmission breather kit
Post by: RivRaptor on June 30, 2023, 12:48:34 PM
2 cent hose with instructions / template and gaskets (which if are in good condition are not needed) $50 bucks.  At least that what I paid.  Makes you love HD for making us pay for a known issue and mod they installed on newer bikes.  You could do this mod without this kit but the 2 cent pre-formed hose has a backing and fits properly in the hole (if you drill it right). 
Title: Re: M8 transmission breather kit
Post by: RivRaptor on June 30, 2023, 12:50:41 PM
More pics
Title: Re: M8 transmission breather kit
Post by: RivRaptor on June 30, 2023, 12:51:16 PM
template
Title: Re: M8 transmission breather kit
Post by: johnmowcop on June 30, 2023, 02:36:44 PM
Thanks for your advice. Do you know if the HD kit has a HD part number. Is it the same part number for all models. How much is it going to be.
Am I going to be drilling holes into the transmission case or the top cover, been looking at videos on YouTube, I am still not clear. Rivraptor, your photographs look like I will need to remove the primary chain cover and drill through into the gearbox, is that correct. If so what happens to the swarf, do I have to dismantle the gearbox to remove the swarf.
Regards
JohnT
Title: Re: M8 transmission breather kit
Post by: KGB on June 30, 2023, 03:53:32 PM
Thanks for your advice. Do you know if the HD kit has a HD part number. Is it the same part number for all models. How much is it going to be.
Am I going to be drilling holes into the transmission case or the top cover, been looking at videos on YouTube, I am still not clear. Rivraptor, your photographs look like I will need to remove the primary chain cover and drill through into the gearbox, is that correct. If so what happens to the swarf, do I have to dismantle the gearbox to remove the swarf.
Regards
JohnT


Part number is 26500027
Title: Re: M8 transmission breather kit
Post by: mjb765 on June 30, 2023, 04:31:20 PM
Thanks for your advice. Do you know if the HD kit has a HD part number. Is it the same part number for all models. How much is it going to be.
Am I going to be drilling holes into the transmission case or the top cover, been looking at videos on YouTube, I am still not clear. Rivraptor, your photographs look like I will need to remove the primary chain cover and drill through into the gearbox, is that correct. If so what happens to the swarf, do I have to dismantle the gearbox to remove the swarf.
Regards
JohnT

You are drilling through the primary case behind the starter. Here are the instructions.

https://serviceinfo.harley-davidson.com/sip/service/document/1280946960640898220

Title: Re: M8 transmission breather kit
Post by: RivRaptor on June 30, 2023, 07:36:24 PM
As other members have said yes, you remove the primary cover and will be drilling in the upper right corner where the template will show you.  Make sure you cover the clutch assembly to catch the metal bits and have some new primary fluid on hand for refill.  A new or sharp drill bit plus a center punch to mark the spot and keep the drill bit centered will help. It's not so bad you'll be fine!  Good luck!