I ran my transmission vent to metal screen filter so nothing can go up it and plug it, a lot of mud daubers here in Texas

 

Found another issue with my vent.. A few years back when I went to 6-speed transmission and a belt drive from Baker I put a different adjuster screw in there.. One that would block trans gear lube from coming back into the primary. It was a half inch longer which is what I needed because of the 6 speed but it also had O-rings on it to prevent the gear lube from migrating out. Anyways I started thinking about that and I went back in and took a look since I reinstalled my OEM primary and sure as **** I had no vent from the primary to the transmission.. That was for about a year.. I'm still running the baker 6-speed with the OEM primary and I did a little investigating and Jim's had listed a 2 3/4" adjuster screw that does allow the primary to vent so I called them but they said they don't make them, Barnett does.. currently Barnett makes all Jim's clutches and parts. So I called Barnett and gave him the part numbers that I had found on a PDF.. They we're able to confirm the part number and said ok that'll be $16 and I said no problem send it.. If any one wants to know the PDF I found was t434-535.pdf. It's in the attachments below..

 

This is all i did , works fine and you cant notice it small hole in top derby cover bolt.

 

How often do you get fluid coming out ?

 

I see a little bit of an oil smear after a decent ride on a hot day but nothing that bothers me, when i first did i noticed it a bit but not lately. i might have had a little bit too much ATF in the primary on that oil change. its certainly not blowing oil every where. if everything else is sealed properly remember your only releasing pressure from your expanding primary fluid. give it a try if you don't like it its only a $2 bolt to replace.

 

I like the hole in the bolt trick. Seems like a simple solution. I suppose a little moisture (rain or washing bike) could get in but reality I don't think it would be that much unless you really tried.

 

I was going to roll up some really fine stainless mesh that i bought for something else and poke it it the hole but never ended up worrying about it.

 

Sorry for the rookie question but how does a properly vented transmission help the primary to vent? The vent tube or top of the tranny top cover just vents to air (or is supposed to anyway).

And my reason for the inquiry. When I got my 1996 FLHT I noticed that oil appeared to be coming from the backside of the inner primary as well as thru the stator plug. Additionally the gasket on the top cover was leaking badly. Hadn't occurred to me trhat the vent tube is plugged and could be the reason for the gasket failure on the tranny and the seal failure on the primary.

 

The primary vents thru the bore of the transmission main shaft. The clutch push rod is undersized of that bore. The throw out bearing shaft and adjuster screw each have a flat machined on them to allow venting thru the trans.

Issue is that many aftermarket clutches can be setup for either wet or dry installation. For a dry/open primary, there is a seal in the clutch hub nut that blocks off the trans from the primary side (like a dry clutch early Evo, Shovel, Pan) and a different adjuster screw to accommodate that seal. If you don't know which parts to use, that type setup on a wet clutch primary blocks off the venting for the primary.

 

There is a flat side on the clutch adjuster screw that allows the primary to vent through the clutch push rod shaft, through the main shaft of the transmission into the transmission and then vents through the top cover of the training...

Sorry t150::: didn't see your post..