I only wish it WAS the transmission vent pipe but I replaced it about a month ago.

 

I don't know about the newer transmissions, but I could definitely see tranny fluid wicking its way into the primary. If you use a different lube in the tranny, especially a gear oil like 75W-90, you can smell when it's in or around the primary. I rebuilt my 2005 FLSTN transmission for a drive issue, and I had nasty tranny fluid leak afterwards. It was a sprocket spacer that was put on the wrong direction/orientation. The mainshaft has all sorts of seals concentric around the shaft (ball bearing quad seal, main seal, primary seal, etc.), plus the spacer. Anyone of those could be broken, shifted out of place, and sure, tranny fluid can wick along the mainshaft towards the primary.

 

Thanks for your reply Brian !
Can any of the seals you mentioned be replaced from the primary side or must the main shaft be removed which would obviously necessitate breaking into the transmission casing ? Oh , and thanks for not asking me if I'd accidentally 'overfilled' the primary . The only way anyone could add 2600ml of fluid through the derby cover hole would be to lay the bike down on its right hand side ! 😂

 

It is not a transmission oil seal, if any of the transmission oil seals leak, the oil will leak out onto the ground, be it quad seal, pulley spacer, big oil seal on main drive gear, mainshaft/main drive gear seal, shift shaft seal, starter jackshaft seal, all will cause oil to leak onto the ground, not into the primary.

The only path oil could take to get to the primary from the transmission would be through the hollow mainshaft.

Is the engine oil level normal? And don`t get pissed because I asked you a question....you are the one here looking for help, not me.

 

Thanks for your reply !
Big differences of opinion on this one !

 

I'd follow-through on the suggestions about trans vent tube being blocked. Make sure it's not.
Drain the trans fluid completely. Refill with a gear oil like synthetic 75W-90. Something that's different from the primary's fluid. Remember its smell. Ride the bike. See if you're getting leaks and where, and what does the leaking fluid smell like. If it's definitely the new trans fluid you put in, then you'll need to take the primary off and look at seals along the mainshaft. Have a genuine service manual handy. Study the exploded parts diagram of the trans, the clutch, the trans housing. You won't have to go inside the trans, but you may need to go up to the main seal and bearing. The hard part is after disassembling up to the tranny, and wiping things down, to get things agitated enough in the tranny to see the leak appear before you. That would usually mean spinning the mainshaft somehow. But, as I recall with my own, I saw wetness between the sprocket spacer and the main oil seal, which I had just replaced.

 

What is your engine oil level doing?

 

The oil level has remained the same Dan.
I really do appreciate your time in trying to help me with this problem.
I've just read through all the previous posts since I put this thread up , but I can't see where I gave the impression I was pissed about anything !
I'm sorry if it came across that way , but it was purely unintentional !It must have 'suffered in translation' as they say !

I am very grateful for ALL opinions and advice .

 

It's probably coming thru the clutch push rod. Make sure you are correctly checking transmission oil with bike level, hot and the dip stick not screwed in.

Then attach a hose to the down vent tube that you can freely blow into it.

If you over filled the transmission, it may have dislodged the seal. There are three of them in the end of the transmission since there are three shafts in one coming out of there. (a groupie) A marvel of engineering at it's best.

The push rod seal, however, is a metal umbrella on the other side of the transmission. The only reason this would leak is someone way overfilling transmission.

 

Hi mate ! My owner's manual says to check the fluid with the bike on the jiffy stand and also says to screw the dipstick back in after wiping , until the o-ring just touches the casing. The transmission vent was replaced about 400 miles ago .