4 speed leak

[mplecha]

I've got a 78 flh. Ratchet top 4 speed, open belt primary, etc.

I've recently gone through the transmission and finally gotten it to stop leaking at the mainshaft. Tonight I rode it in to work. Just a little while ago I noticed a dinner plate sized puddle under the transmission. I don't think it's my main shaft seal. This ratchet top is covered in oil. It seems to be coming from a shaft in the top cover. I didn't take that apart, so I'm not sure what is in there to leak or seal it up. I don't think I overfilled it. I've read to fill it to the threads on the filler hole, but I have way less than that in it. Is this an easy fix? Do I need anymore special tools to do it? Thanks in advance.

[Ohio HD]

The items in red are seals or gaskets, not much up there, and of course the gasket under the ratchet top. Did you have the ratchet top off? It's been a long time since I was in one, but memory says one of the ratchet top screws is a vent, and if it were in a blind hole, the transmission could be pressurizing. Just a though is all. I don't even remember if any of those threaded holes are blind holes or not, been a long time.

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[mplecha]

I had the top off but did not disassemble it. It looks to me like the oil is coming from around 32 where the shaft sits in the top. I'm pretty sure the vent is in the right hole. I blew through it before I put it in, so I'm fairly sure it's not clogged.

[billbuilds]

     I believe that #26 is an oil seal for the shifter cam shaft. A dinner plate-size puddle seems like a lot to come from there tough. Is your sprocket nut torqued correctly? Would advise that you clean it up good, go for a shorter ride and see if you can nail down where that leak is coming from.  Bill

[Reddog74usa]

Make sure you remove the breather screw and clean it out.

[dirtymike]

reddog where is the breather screw in the diagram. Ive had leaks from cow pile transmission and it seems to always be the main drive gear seal.

[Reddog74usa]

It should be in the area of #32 in the diagram. It is one of the screws that holds the ratchet top on, has a larger head than the rest and you should see a hole in the side of the screw head. The screw is hollow and allows air pressure to vent thru the hole in the side of the screw.

[Harpo]

As a side issue, you said that you had less lube in the tranny than recommended.  If you've got the small needle bearing style throwout bearing (which I'm pretty sure that you do), you are inviting failure unless your oil level is up to the point to at least partially keep oil on it.  Those little things won't last very long otherwise.  If you've got the large (bullet proof) bearing (like a panhead tranny) you can get away with your oil level being a bit lower than recommended.

[Ohio HD]

Location of the screw on a ratchet top.

[Hossamania]

Location of the screw on a ratchet top.

If you keep posting up info this well, what is FSG going to do?

[Ohio HD]

Who do you think is pulling my strings......   

[Hybredhog]

   Yes, oil up to the threads, WHEN LEVEL. if done on kickstand, its to full.  But the amount of oil your talking about is probably to large for any upper gasket failure. Did you replace the main drive gear brass bushing? not doing so will result in almost never being able to stop a leak.

[guppymech]

reddog where is the breather screw in the diagram. Ive had leaks from cow pile transmission and it seems to always be the main drive gear seal.

The cowpie trans doesn't use a screw for the vent, there is a .040 dia or so hole on the aft side of the cowpie itself that vents the trans.

[dirtymike]

Ok which is it, vent hole or vent hole screw. little confused here. dirty

[Ohio HD]

Which transmission do you have? Ratchet top uses a screw, the maytag uses the vent hole that guppymech is showing us.

[dirtymike]

Same as mplecha, ratchet top. Either way that is a big puddle for a vent hole.

[Hybredhog]

    On the cow pies, HD had a service bulletin in about '79-80 about the breather hole being blocked by the frost plug that covered the pivot shaft access (hole drilled to high). but that caused other gaskets to blow.

[mplecha]

It's been a while since my first post, but I'm still having the same issue. I've sealed the main seal. I cleaned my transmission off and went for a short ride. Afterwards, I had a small pool of oil on the top near the vent. I'm not sure if its due to the bike leaning on the kick stand, but the oil is collecting in the hole for the shifter drum shaft. I have a new v twin top cover on, and the leak is exactly the same as my original top. I can't figure this out. its definitely coming from above the top cover, but my vent screw is dry. I know this picture is not good, but you can see where I'm talking about.

https://photos.app.goo.gl/K59eefX4gMhLku8N6

[xlfan]

It looks like billbuilds nailed your problem in post #3

[drifter]

There should be an o-ring on that shaft where the oil is coming out that is supposed to seal it.  At the other end of the shaft is a groove the set screw fits into to position the shaft.  You could pull the shaft out slightly and put a light coating of Three Bond sealer on the o-ring and put it back together. 

You can also spend an hour watching this video about a ratchet top.  That video is #103, they are numbered 101 through 109 on rebuilding 4 speed ratchet top transmissions.  https://www.youtube.com/watch?v=iCYrsvOB2Q8

Good luck.

[Burnout]

It looks like billbuilds nailed your problem in post #3

I wonder if the drum shaft is installed backwards or some other malfunction?

If the shaft is not loose wash the oil off and coat the end of the shaft and hole with some ThreeBond as suggested.

[mplecha]

I did that and it seems to be good.