Oil Leak on Final Drive?

I'm replacing my rear tire (FWIW, the IRCs are *MUCH* easier to get off the rim than the $#@! Bridgestones that I believe need small explosives to remove; that said, I'm putting the Michelin Power Pure on). Scoot is a '12 with right at 6,000 miles on it.

The axle looks like it has oil on it, although it's certainly mixed with a darker colored kind of gritty substance (moly paste?) - I'm talking the oil on the splines, not the road grime mixed with it on the bottom of the final drive case. Looks to me like it's been leaking down the final drive case too.

Before I take it to the dealer for warranty (I like doing my own work, but this looks like real work to me to change that seal - and a bit beyond what I like doing on the bike), I thought I'd save myself some embarrassment and ensure that this is NOT the typical way it is supposed to look (I can't imagine that, but...).





Okay, back out to finish putting this tire on.

Looks like you have a oil seal leek al right .Generally It's an indicator that the bearing is worn out causing the shat to vibrate .If they replace the seal Keep an eye on it before the warranty ware's out.

A little rare but just the same it looks like the seal is leaking.Some of the residue might be from a little grease they put on the splines. Although the final drive does not hold much oil and there is not a excessive amount by the seal, have you checked the level? Unfortunately this is something that should be looked at by a dealer while it is under warranty just in case something is going on in the final drive. Howard NWSSC

Thanks Tinman & NWSSC.

I thought about grease separation too - I figured if that was the case, others probably have seen it. Certainly it still could be, but I'm leaning towards oil leak for two reasons: 1) doesn't sound like anyone else has seen quite what I've seen and 2) there seemed to be more oil near the engine than near the outboard bearing (which had little if any oil) and I would think the outboard bearing, being next to the radiator, would be hotter.

As for oil level in the final drive, checked and it's right where it should be (when the transmission was warm, a bit came out the top hole). If it's a leak, it's leaking very little (but based on what I could see, that's what I would expect. There's also absolutely zero oil residue on the vent tube or around it inside the CVT case. FWIW, I changed final drive oil about 1,300 miles ago using genuine Honda oil with no evidence I overfilled (after I saw the apparent leak, I checked the level and verified that the vent tube isn't blocked by blowing into it).

I'll let everyone know what I find after either I just break down and let someone else touch my bike or I give a go at replacing that seal (I'm not thinking it's a bearing, but wouldn't completely eliminate any chance I'm wrong on that). A bit more looking at things and it looks like this final drive is actually remarkably simple (and, as is typical Honda, elegant).

Interestingly enough the manual doesn't say to grease the splines at all although I did put a smear of ASP on mine just as I used to every time on my Pan and Deauville. I hope that I'm not making future problems for myself !

After sleeping on this for a bit, I think I'll go ahead and do the work myself. Reading other posts about the dealers not always having the clutch bell removal tool, I don't fancy sitting around waiting for them. I really don't want to see someone beat the heck out of my scooter to get it back together or try to take shortcuts because they don't have the right tool - so I think I'll do the work since the parts should be cheap. So I went ahead and ordered the clutch bell removal tool. It helps to have two of these Swings in our family, so it's a bit easier to justify a special tool.

Looking at the final drive service, it looks like the final shaft should pull right out and I should be able to get at the bearings and seals easily enough with relatively standard bearing pullers and drivers. That is assuming that the dye ends up telling me that it really is the final drive and not grease separation. Hopefully the bearings all look good and it's just the oil seal on the final shaft - or even more hopefully just grease separation.

At least I got out today (the leak is so small it's not enough to keep the bike in the garage - it's small enough that the risk of oil on the tire is pretty much zero).

Looking at the Honda S/W service manual (page 11-8 @ 11-9) you could find yourself in for quite a job without a couple of special tools.Although the bearings are retained by a snap ring they are also pressed into the transmission cover and the final drive shaft is also pressed into the bearings.
When you mentioned dye,did you install dye into the into the final drive?I have used a special dye in engines and both standard and automatic transmissions with some excess but it can take some time. Another way to detect leaks in all the above is to use slight air pressure (5-8 lbs) through the vent.I would give it some air pressure for a couple of seconds and then let it set for a couple of seconds and repeat it several times. It worked exceptionally well on engines and automatic transmissions without getting them exceptionally hot and then having to dissemble them.

To remove the clutch bell ,all you need to do is apply the emergency brakes . The bell will slid off ,and the seal can be removed from the outside .If you don't fell any play on the shaft,just replace the seal .It's possible the seal was damaged from new causing a leak . I would only replace the seal . for the amount of milage your swing has,and save some un necessary work.Apply a little greece on the seal to install,and whip off excess .and keep and eye on it till next oil change..

I can get the clutch piece off that has the big spring, the clutch pads, etc - that's easy with the parking break and a breaker bar (and, sometimes, a zip tie to hold the rear main break if the parking break isn't enough). But the piece I'm talking about - the bell - is the piece that's left after you pull the pads and the rest of the assembly the pads are part of off of the bike.

I didn't try really yanking on the thing but it's definitely on there fairly well, and after a long while trying to find a bolt with threads that matched the clutch bell's threads (good luck with that!), I gave up and just bought the tool rather than getting something fabricated. I'll fabricate the installation tool which presses the bell onto the drive shaft.

The seal I'm trying to get to is not on the drive shaft (the drive shaft on these is the shaft that goes through the clutch), but on the final shaft (that's the shaft that goes through the rear wheel). Honda's terminology here threw me too, but I suppose the drive shaft on a car goes to the diff, not the wheels, so I suppose it makes sense. The seal is inside the final drive case, with the bearing between it and the wheel - the only way I can see to get at it is to remove the cover of the final drive, which doesn't look hard (once you get the clutch bell off!).

That all said, I've had the dye in for a week so far with no evidence of a leak. I probably will need to pop the rear tire back off and check there again, but I'm in no hurry since the leak appears at worst to be very small. If I don't see dye there, I'll go back to the grease separation theory. As for air pressure, I'm thinking if I see no evidence of a leak (particularly the dye), I'm going to just let it be and assume that someone just slopped too much grease on the bearing (that said, I'm really hesitant to think that since the '07 and the '12 both have pretty much exactly the same assembly faults otherwise, but not this one - it's amazing how consistent Honda is assembling them).

If all you want to remove the seal and replace with a new one ,you remove the seal from the side that you took the picture from .Just pry the seal off clean the surface apply a little greece on the new seal and shaft the tap the seal with a rubber mallet.I you want to remove the clutch bell ,a special toll is needed.Get yourself a service manual A picture is worth looking at.

tinman wrote:

If all you want to remove the seal and replace with a new one ,you remove the seal from the side that you took the picture from .Just pry the seal off clean the surface apply a little greece on the new seal and shaft the tap the seal with a rubber mallet.I you want to remove the clutch bell ,a special toll is needed.Get yourself a service manual A picture is worth looking at.

There are two seals on the final drive shaft as it leaves the final drive. One seal is accessible on the outside (dust seal), the other only from the inside (oil seal).

The seal towards the wheel (that is in the picture) is a dust seal, not the oil seal. The order is basically:

TIRE --> Dust Seal --> Sealed (non-Oil-immersed) bearing --> Snap Ring --> Oil Seal (to keep oil out of the bearing)

The dust seal (accessible from the tire side of the final drive) doesn't keep oil from leaving the final drive - the oil seal, which is on the other side of the bearing, does that. I don't see any reason why I would replace the dust seal unless I tear it up pulling out the axle.

The picture I'm looking at is at the bottom of page 11-5, which is a picture of the inside of the final drive with the shafts removed. The picture right above it (in "bearing replacement") shows the seals in cutaway.

I might have called it a oil seal but with the milage and still under warranty It's possible that the ( dust seal was over packed with greece when put into place, and the heat generated from the drive shaft force the excess to leak out the stains don't appear to wet and the greece applied to the spline for the wheel rim might be in excess causing what is on the housing .I would just change the ( dust seal ) if the warranty is to last for a while ,and see if the leak continue ,and notify the dealer of your concern,and show them the pics,and chose the down time in the off season.

Tinman is right I think - I think there was just a bit much grease on either the dust seals or the shaft or the exposed bearings. Whatever it was, it's not a problem - I've been several months now and thousands of miles, with only a little bit of evidence of grease on the bottom of my final drive, with none of it glowing under UV (I added florescent dye to the final drive in May). No need to replace the seals, as it's clearly not final drive oil leaking out.

Speaking of Tinman, i wonder where/why my fellow Canadian is hiding. I see he checks in often but is no longer posting!?!?!

I had the same problem. I rented a pulley puller from Autozone. It was free (+deposit). Got myself a pipe to mount it back.

I purchased all the seals .... I took all it's guts out. What a waste of time.
I should've just got the screwdriver and pulled the piece of S*&^*t of a seal out to start with.

But with no user manual ... who knew. So before you jump to spend hours and tools and money and arrrghhh .... go buy that seal. Stick a flat head screw driver that take that thing out of there.

LN

Which seal did you replace? My understanding from the service manual is that the dust seal can be replaced externally but the oil seal needs to have the final shaft (that is, the shaft that the wheel is on) pulled because it seats against a ridge being driven in. If the dust seal fixed it, I'm thinking even that didn't need to be replaced - it was just excess grease that separated.

https://app.box.com/s/srzbqlm7106kzjwbc8bk
https://app.box.com/s/pcd3e72pdb367f7ackke

I could swear that only the external seal had to be changed.
I replaced all of the them. Took about an hour with an aluminum pipe and an Autozone pulley puller, no book, and not knowing what to do.

External dust seal has a metal case. I had a hard time pulling it out. Be gentle with the new one. it has to be "flushed" with the edge put it in to much and you need another one cause you can't take it out without damage

If you replace all of them you my need a tube of crank case seal, cause there is a little case with gears inside.

I will clean first than replace the external first than wait and see. If you see oil again, just clean it. and replace the inside seals.

good luck

bump   found this on  google searching for same issue

https://www.silverwing600.com/t10456-final-drive-leak