are you referring to the rubber seal on the drive shaft all the way back where the drive shaft goes into the gear hub on the wheel,

or did you take the side cover off the rear of the engine by the drive shaft universal, and the oil is leaking from the engine in front of the universal out of the back of the engine?

also how much is it leaking? is it making a puddle on the garage floor every night, or is the drive shaft just getting a bit oily?

 

I had read that the neutral safety switch usually leaks so I took the cover off.
Looks like it’s coming from the back of the engine under the rubber sleeve. (Not the neutral switch) I assume it covers the universal. The oil is unusually clean though.

 

When you degreased the engine, did you scrub it down every place that looked oily?

There is a rubber boot over the differential on the back of the engine.

I thought my 650 was leaking out of the engine where the drive shaft exits the case. It was actually the rear tappet cover all the way up on the head. I had adjusted the valve clearance and did not replace the o ring on the tappet cover. The oil started oozing out slowing, all the way down the side of the cylinders to the case, spreading out everywhere, and then dripping a bit down by the drive shaft.

I thought it was the drive shaft seal flinging oil around while it was spinning, until I soaped the whole back of the engine down with laundry soap. Then when I started it up I could see the oil oozing out all the way up on the tappet cover on the head.

If you have cleaned everything good, dont assume its coming from one place or the other until you can see new oil coming out at only one place.

The other thing I would suggest is to make sure you did not overfill your crankcase. Sit on the bike with a small mirror in your left hand and reach down and look at the site-glass window, holding the front brake with your right hand. you can lean the bike a bit left and right - if you cant see the oil line in the top of the window, even when you lean the bike to the right, your case is overfilled. That can cause oil to be forced out of seals that normally would not weep while the bike is running.

If you are sure its the rear drive shaft seal, you can find the Vstar 650 factory Service Manual online as a PDF download, from a couple websites for free. There is a section there on replacing that shaft seal. I have never heard of anyone needing to replace it, so I dont know how much work it would be.

 

Here is a picture of the offending leak

 

Ok. Thanx.
I’ll have a closer look tomorrow and I’ll let you know how I went.

 

I’m back.
Ok. I had a real goos look again. I pealed back the rubber cover/sleeve on the engine block side of the shaft. I wiped down the inside (it had oil spray inside) then I degrease the whole bike again. I rode it to work and back.
Guess what. Still leaking from the same spot.
I’m guessing there must be a faulty seal.
I remember when I had my tires replace a couple of years ago, they removed the driveline to get to the rear tire. Only took him a minute.
Question is. Once I remove the drive shaft, would that seal be easy to access and replace?

 

I looked thru the service manual, there is no explicit set of instructions for just removing that rear seal.

With the back wheel off the bike, you pull that boot off and you are looking at the universal. You can split the universal by taking... looks like C clips off. Then there is a nut on the "middle gear shaft" that lets you take off the other half of the universal.

The seal is then right there. I dont know if the seal can be pried out without removing the middle shaft first. Maybe someone has done this or had it done on their bike and can give more information.

How many miles are on the bike? Did you check and make sure the oil is not over filled?

 

I did a quick search here and Im not finding any posts where someone had the mid shaft seal leaking (part that drives the universal)

there are several threads with a leak somewhere nearby, that looked like a shaft seal.. so still unless your bike has a lot of miles (like 100,000) its not likely to be the shaft seal

but one thread said once you pull the universal apart and take that nut off, you can pry the seal out... so its not an engine pull, or partial tear down... But get a few more opinions on this before you tear into things.

 

I've removed many what I call blind seals (seal without a lip) many times in tight areas. You can take a screw and screw it in the seal. With vise grips pull on the screw. On bigger seals a slide hammer makes it easy. Works good.





Here's a video.

https://youtu.be/Ehqz1Y-ggGo

 

Thanx guys.
The bike has only done 25,000 km
I may have overfilled it before I went away. The level was on the higher side in the window, but now it’s ok and still leaking.
KCW. Could you post a screenshot of that page on the manual or a link to the manual if it’s online.

 

Repair manual.

https://www.google.com/url?sa=t&sou...WiVt8KHcSSCjMQFjAAegQIARAB&usg=AOvVaw2PwqYYtju1c6ZiIW6p1YpQ&cshid=1555636968687

Screenshot on middle gear section.

 

?Thank you.
I’ve been catching up on some gardening today, scoring some browny points with the Minister of Finance and Pleasure.
I’ll have to wait a couple of days before I can work on the bike.
I’ll let you know how I went soon

 

Update.
Been to a couple of bike mechanics. One is “supposed” to be the best and the other is the local Yamaha dealership. None have seen a leak in that area.
They both told me to drop it off and they’ll have a look (and charge) because these bikes shouldn’t leak in thare.
I just called a Yamaha dealer outside of town and he told me my mileage and where the leak is coming from. He was only out be 1100kms.
Apparently the oil seal in your image labeled “9”leaks after 30000km. I’ve done 28900.
He even gave me the part number. Guess who’s getting my money when I upgrade?

 

That looks like a relatively simple o-ring to replace: take off the back wheel with drive shaft

pull the C clips off the universal and split it

take the nut off to remove the universal

take the 4 bolts out to remove the bearing (assume you have to drain the oil first...)

and the oring is right there.

I see a part that is not labeled on the drawing, between 8 & 9... I would assume the bearing is in the oil and the mystery part might be a shaft seal? odd that its not labeled in the diagram.

I noticed when I wash my 650 I see oil rainbows in the water draining off the bike. Wiping it down and looking under it with a mirror that area on my bike is a bit oily - enough to make the lower swing arm grungy, but never enough to drip oil on the garage floor.

My bike has 42,000 miles on it, and I dont appear to be losing any oil between 4000 mile oil changes - never have to add a drop. So maybe mine is oozing just enough to get things oily on the output side of the shaft.

Its pretty much impossible to make a shaft seal that does not at lease keep the output shaft wet with oil, as long as its not dripping or losing oil while the bike is in gear and running.

 

Correction. That unlabeled part is the offending seal.
I miss understood the mechanic.
Looks like the job is easier than I thought.

 

I’m back.
I opted to get the bike fixed at my local dealer.
Just got it back.

They replaced the seal and found the collar (#8 on the diagram) was worn out where the seal sits, so they turned it around.
There was also a small leak at the front cylinder inspection cover and I also got them to replace the neutral safety switch.
All up it took them 5 hours.

$440 au. I’m happy.?

 

good deal, there are only two ways to kill a Vstar engine

1. rev it up to near the red line in gear, then instead of shifting up, kick it down and let out the clutch, mechanically redlining the engine.

2. Run the engine with the oil pump sucking air, either by draining the oil and forgetting to put the new oil in the bike, or having a small oil leak and not checking your oil level every day.

I looked at a Vstar 650 last year, only 4k miles on the odo, owner said the front piston was "making a clicking noise".

Beautiful bike, asking $1500 - he rode it 35 miles away, it starting making a knocking sound, and he drove it 35 miles back on the interstate. He drained the oil out, there was only 1 quart in the engine.

It had been leaking oil for months, leaving a small puddle on the garage floor. It was also leaking when he rode it. Engine destroyed.

Best to get after any oil leaks when they start, because they will only get worse.

keep an eye on the shaft for signs of leakage for the next year or so

Since this is a rare place for a leak to happen, its possible the bearings on the shaft are failing, making the shaft loose, making the seal leak. Something to keep in mind.

When a bike has an unusual problem there might be a deeper issue.

 

I just did that repair on my 2008 Vstar Classic. I does require getting the housing out by removing the rear swing arm. Which the exhaust is in the way to the right side swing arm bolt. The rear fender swings up and locks in place by just removing the rear fender screws. Really handy! Taking the u-joint apart was not to bad which is required to get the shaft nut off and get the seal off. Need to pound out the pressed in pin on the ujoint. I used a socket that was fit the hole diameter loosely. The seal I took out by drilling in and screwing some sheet metal screws in 4 places and some precision pull pounding. (new term).

I had two leaks one from the shaft seal and one from the neutral switch sensor. I am not sure if the oil can get inside the boot from a leak of the neutral switch sensor. But my shaft boot was full of oil and did not appear to be connected to the Neutral sensing switch plate.

While I was at it a cleaned and re-lubed the shaft and drive splines. and changed the rear end oil. I am a newbie with this bike. Just started riding this spring. And have not done much mechanicing in many many years. Have put about 400 miles on since the work and no leaks! Yahoo. It's not that hard to do but just have to be in the mood for it... It's likely gonna cost $800 bucks in a shop. An old thread I believe said they got it done for $400. That is if you can find a mechanic that has done the job before.

Peace to you. and good luck.