Another leak??? CRAP!!!!

[nighthawk11]

I hadn't ridden in a couple of days. Went to go out and found a small leak under the final drive, on the ground. It was gear oil, very black. I've just replaced this last month with Mobil1 75w-140. Took her out for a little spin and of course got gear oil on my clean whitewall. What could be causing the leak? Should I have gone with a 95w oil instead?

[nighthawk11]

it's been about an hour and don't see it leaking. After looking closer, it only sprayed about 1/4 of the wheel, where I originally noticed it. Another thing, should the gear oil be that black after only a month?

[ringadingh]

It shouldn't be actually real black after that time, but from where the leak is it could be picking up grime and rubber particles from the damper inside the hub.

[nighthawk11]

It's been 2 hours and don't see it leaking. I' m going to drain it, refill, and clean up, then go for a short ride and see what it does.

[blowndodge]

Did you put a new tire on recently, like real recently? If you did you could have dinged up something re-installing the wheel. Leaks from that locating are rare. Make sure you dont overfill it either. Most have repored that they put a 2 inch block under the kick stand to right the bike up closer to straight up and down but still plenty of lean then fill until the oil starts to come back out. Over filling will cause leaks so this is done as a leak preventative solution. Doesn't take much oil to do the job in the rear end. In other words, slightly underfilled is better than slightly over filled.

[nighthawk11]

it didn't leak overnight. The oil I took out didn't look anything like what I found on the floor. This was slightly brown and very clean looking. The stuff on the floor was very black. Anyhow, filled her back up, took it for a quick spin. Now it's been another hour and no leak. I'm baffled at this point, but I'll keep a good eye on it

[dogdoc]

good luck with it.

[nighthawk11]

Dang it!!!! Went out for a short ride, and it did it to me again. What coming out is very black in color. Nothing like what I just put in there today. I really need some help with this one folks. This looks like really old gear oil. Could there be some place in there where it would pool?

What you're seeing IMO is this: Gear oil is leaking slowly past the main ring gear seal. That means it leaks right onto the rear wheel splines, and those splines are not sealed from dust and dirt. The oil is washing out some dirt and grease from the splines, and that is slinging out the crack between the hub and wheel as you ride.

But if that rear hub was removed recently, like the tire was changed? And the splines were recently greased, then it could just be grease slinging through the crack. This always happens to me the day after I change a rear tire. Usually I clean up the wheel a couple days later and it's fine again until I grease those splines again.

Gear oil and grease smell quite different, so I'd smell what has slung off carefully to determine what it is. It could, as I mentioned, be a mixture of the two, and that might be difficult to determine.

If you think it is gear oil leaking, and you continue to ride the bike, please keep an eye on the gear oil level. That box only holds about 6 1/2 ounces, and if most of it leaks out you could chew up the gears and bearings. They are VERY expensive to replace. A complete new rear assembly will set you back $2000 or so.

[nighthawk11]

Thanks for that info Cad. The rear tire has been on for about 800 miles or so. You're right though, it does seem more like grease than gear oil. When I drained it earlier today, there seemed like there was plenty in there. If it's gear oil leaking now, why is it so black? it's got fresh new stuff in there.

Oil leaking past a black rubber seal can carry black rubber and dirt from the seal with it.

Did you change the wheel yourself, and did you clean out the splines yourself? If so did you get them nice and clean? If you took it to a shop it's possible they didn't clean out the old grease and dirt at all. (It's tedious.) If they just slapped some fresh grease over it and put it together there is a) too much grease in it and b) the old grease is dirty, and c) the new grease gets hot, liquifies a little, and thins the old dirty grease which then slings out all over.

[nighthawk11]

Shop changed the wheel a few months back. They did a poor job in my opinion. They're WW tires and they didn't take the blue protective coating off before they put the tires on. Needless to say, I won't be going back there. If it's a true leak, it'll continue to leak. I'm going to keep a close eye on it. If it doesn't get better by Monday or Tuesday, the 'Nad's going to a shop....not the same one.

[nighthawk11]

I drained the final drive again, and put it in the same container I filled it from. I didn't lose any. It was the same level when I measured before filling. Anyhow, I thought I would try and use Valvoline semi-synthetic 80w-90. It's still slinging out some oil though.

[nighthawk11]

ok update. I decided to drain the drive again and measure what comes out. I got 250cc+ out of it, and this is filling it per the manual. So, it was overfilled. Anyhow, refilled with 200cc and went for a drive. It still leaks a bit, but not as much. Now I'm concerned that the oil might be breaking down the spline grease, so i'm going to have to go in. I'm buying a lift tomorrow to take the wheel off. This is the part where I'll need help. After I get the wheel off, how do I get to the seal, and which seal is it?
Thanks...

You can look up the part here:

http://www.brocktoncycle.com/fiche_select.asp

On the parts diagram for my 2004 model it's listed as: "92049B SEAL-OIL $16.93"

I do not know if it will come out without disassembling the gear case though, and I don't have the manual handy. I can check later.

Also, it is probably available cheaper elsewhere.