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Is this a main oil seal leak?

Campagman

Cruisin' Guzzisti
GT Contributor
Joined
Dec 1, 2009
Messages
346
Location
Manchester, UK
Got out today and did around 60 miles, first time this year. On returning it was a little wet and I spotted some oil drips on my drive way. The oil was from the back of the sump up around where the centre stand pivot is. :S

Took this photo. The oil is coming from above the sump joint.

Appreciate any comments.
I've left in the garage with a cloth underneath the see how much it's loosing.

Oil Leak
 
Question is, can you tell if it's coming from the pan joint, or is it dripping from the transmission/gearbox bell housing drain hole? Usually it takes cleaning it off, and letting it sit to figure out if it's the latter. Which if it is coming from the drain hole, then it is indeed a rear main seal (or for older Tontis, the cam plug on occasion).
There has been one Stelvio here in L.A. that has had a rear main seal replacement already.
 
The other possibility is the transmission input seal. Either will show from this location. First determine if it is engine oil or gear oil. Probably doesn't make much difference as you need to split the bike to replace either.
 
It may be neither. Some early 8V motors had a problem with the seat for an o-ring on the rear main bearing flange, (The design and oil delivery system differs from earlier models.) that may require removal and machining of the flange.

Not saying this IS the problem. Simply that it is another possibility.

pete
 
Thanks for the responses, I'll get another photo in the morning.

In any event it seems like its a major job to fix, engine/gearbox out?
 
I cannot tell from your picture if the is a rear main leak or not. I had this problem and there was lots of oil under my bike. A 6 inch puddle. If it turns out that it is, I hope you are still under warranty!!
 
Ok, checked it again this morning. This is what it looked like. There were a few drips on the cloth on the ground.


Oil looked like this, it looked the same as both the engine and gearbox when I opened up the dipstick and the fillplugs.

Cleaned it up and ran the bike for a few minutes
It doesn't look like the upper sump joint line that's at fault, the oil tracks out of the opening that you can see the flywheel thru. From wiping clean and leaving a few minutes ,you can just seel the oil on the vertical edge of the opening.
.

The bikes a 2008 model with around 7400 miles on it. So not under any formal warranty. I guess I'll have to leave that to my dealer to challenge. I'm away all week, so I've left it for now an I'll see how it looks next weekend.

Appreciate any further observations.

Stelv8V RearMainLeak1

Stelv8V RearMainLeak2

Stelv8V RearMainLeak3

Stelv8V RearMainLeak4
 
I'd guess gearbox input seal. Newish bike maybe some one-filled the gearbox. At least the fly wheel doesnt have to come off but you need to change the clutch plates. Doesn't need a main dealer who were expensive on my bike.
 
The thing is this is all guesswork. The only thing you KNOW is that there is oil appearing and it seems to be coming from the bell housing. The only way to find out where is, I'm afraid, to take the gearbox off and that is most easily done by simply dropping the entire motive unit out of the frame. With a Stelvio this will be a bit of an embuggernce but nothing like the hassle of a Norge, just bite the bullet and get on with it I'm afraid.

Do be aware that to get to the rear main seal and bearing flange on an 8V requires a special compressor to facillitate the removal of the diaphragm spring centreplate to access the flywheel bolts. Yes, there are ways to work around it but as in so many cases having the tool makes a world of difference to the ease of the operation.

Also 8V clutch and flywheel is completely different to earlier models Nel. only a single plate. How prone the plate is to contamination in the event of leakage I'm not sure.

Pete
 
I heard there was a problem with some flange bolt holes not being threaded fully to the bottom. That cause the bolts to reach full torque, before they were even bottomed out. That would cause a leak.
The fix is shorter bolts.
 
Well, got home after a week away and checked again, still leaking. :(

Rode it upto the dealers today (approx 26 miles), nice a steady, didn't want a big oil spill right under the back tyre, parked up. Within a few seconds there was oil dripping on the road. :( :(

So I left it with them. :cry:

How many hours to pull the power train out and split it? :( I'd hope the seals are readily available.
 
Hi Campagman, I am the one who had rear main leak(s). First one was fixed right when the bike was new and was fine for 4700 miles. Bike was tied up all winter and I rode it in the spring and all summer. In beginning of October it started to leak again! As I understand it, the part that holds the rear main is some sort of a housing bolted up to the rear of the engine. I understand that Guzzi has modified that part and you want to get the newly modified part in order to correctly fix this problem. Apparently they didn't supply my dealer with the updated part the first time around. You should try to Guzzi to pay for this; it is either a design flaw or manufacturing defect! Both times my bike has to be completely torn apart to get to the fix. There are several Stelvios that had this defect. My dealer has really gone to bat for me with Guzzi and hopefully yours will also.
 
I have had an oil leak from the rear main seal and the pictures that are posted looks exactly the area where my leak was coming from. I had it fixed approximately 2-3 months ago. It took them about 2 months to get everything situated. I have to bring her in again for there is an annoying sqeeking/whisling sound when I press on the clutch. Also makes some abnormal noise when it's in nuetral just Idleing. Pain in the Ass!! Good luck lads!!
 
I was on a motocycle trip to Italy in 2001 and the day we were supposed to ride the Stelvio pass, the brand new BMW that I rented broke down and I missed that entire day of riding. I had to haul the bike to a BMW dealer and rent another machine for the remainder of the vacation. Call me “Lucky Lucky”!
 
Bob Bernstein said:
Hi Campagman, I am the one who had rear main leak(s). First one was fixed right when the bike was new and was fine for 4700 miles. Bike was tied up all winter and I rode it in the spring and all summer. In beginning of October it started to leak again! As I understand it, the part that holds the rear main is some sort of a housing bolted up to the rear of the engine. I understand that Guzzi has modified that part and you want to get the newly modified part in order to correctly fix this problem. Apparently they didn't supply my dealer with the updated part the first time around. You should try to Guzzi to pay for this; it is either a design flaw or manufacturing defect! Both times my bike has to be completely torn apart to get to the fix. There are several Stelvios that had this defect. My dealer has really gone to bat for me with Guzzi and hopefully yours will also.


Anyone any more info on this, especially if Guzzi recognise it and modified the part?

PS I rode the Stelvio in 2008 on a bicycle form about 1400m above sea level to the summit at 2800m, took a while, I think about 1 hr 30, didn't get chance to ride down though.
 
GUZIRDR said:
Yes, it sure is! I would love to ride one day!! On my Stelvio of course!!

Did the pass several years ago when on a motorcycle vacation, Desmond Tours (now defunct). Had so much fun we ran it twice in one day!!
 
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