Fixed - 2019 V7 III Final Drive Leak

[Solorider73]

Update June 2023 with 10,600 Miles
New Rear Drive from Piaggio.

Fixed
Rear hub had a hair line crack allowing oil to pass the seal when hot.  MG replaced the hub under warranty with no leaks at 1500 miles as of this writing.


Original
Rode my 2019 V7 III Stone for a few hours yesterday. Looking over the bike when I got home, I noticed dried oil on the rear wheel. The vent plug is clear and no oil has been added since it's 600 mile service. It appears to be coming out around the hub. I assume this is a prelude to the infamous rear drive seal leak? Any thoughts? Currently has 3100 miles.

[Siamese]

Veering slightly away from topic, but the manual doesn't call for final drive oil replacement at 600 miles, does it?  I was thinking not until 12,000. 

[Solorider73]

You may be right, I'll have to look at the manual.  I just assumed all fluids were changed at the first service.

[Siamese]

I recall being surprised that engine and gearbox get changed at 600, and was surprised that the final drive wasn't due for a long time. 

So, I haven't done mine yet, so I don't know anything about it, but could the oil be a result of an overfill? 

[Solorider73]

I recall being surprised that engine and gearbox get changed at 600, and was surprised that the final drive wasn't due for a long time. 

So, I haven't done mine yet, so I don't know anything about it, but could the oil be a result of an overfill?

I have not placed any new oil in since new so it's not likely from over fill unless it occurred at the factory.

[Wildroamer]

Hope it gets handled without much fuss. I'll be paying attention to what you find out, just passed 2,000 on mine...
Oh, and I'm pretty sure first service on all V7III models is at 900 miles, not 600.

[Kiwi_Roy]

Take a 10mm Allen wrench and remove the plug from the rear, nothing should run out but be prepared for it to be over-full.
I found mine had water in the oil, I suspect from riding in the rain or perhaps washing.

[Solorider73]

Take a 10mm Allen wrench and remove the plug from the rear, nothing should run out but be prepared for it to be over-full.
I found mine had water in the oil, I suspect from riding in the rain or perhaps washing.

Thanks I’ll try it after work today and report back.

[Zoom Zoom]

Veering slightly away from topic, but the manual doesn't call for final drive oil replacement at 600 miles, does it?  I was thinking not until 12,000.

The manual calls for the first service to be performed at 1500 kilometers. (932 miles.) IIRC, you are correct about the rear drive but...

I did notice some extended intervals that I thought were optimistic to say the least. That being said, exceeding said service interval cannot hurt. Even though it is a few bucks more out of my pocket, I think I'll do the gearbox and final drive when I do the engine oil and filter. There is simply nothing detrimental to doing more frequent service.

John Henry

[Dirk_S]

Take a 10mm Allen wrench and remove the plug from the rear, nothing should run out but be prepared for it to be over-full.
I found mine had water in the oil, I suspect from riding in the rain or perhaps washing.

My experience with water in the final drive, which happened often to me before sealing up the rubber boot, always resulted in leakage out from the breather. If this is radial, then methinks an overfilled system is just an add-on headache that’s not hard to remedy. Correct me if I’m wrong, but leakage from the hub screams of a bad seal.

[Kiwi_Roy]

My experience with water in the final drive, which happened often to me before sealing up the rubber boot, always resulted in leakage out from the breather. If this is radial, then methinks an overfilled system is just an add-on headache that’s not hard to remedy. Correct me if I’m wrong, but leakage from the hub screams of a bad seal.

When I removed the drive shaft for greasing I found some water at the far end spline, I suspected this came in around the boot but also the flange where the hub bolts to the drive shaft tunnel has no gasket so it could get in there
The check valve in the vent is a one way (ball bearing sitting on a seat, no spring) that would normally lead to a negative pressure as the hub heats then cools, it could possibly stick to the seat and cause over-pressure as the hub goes from cold to hot.
BTW I found the hub on my bike gets almost too hot to hold your hand on after 100 miles or so of brisk riding.

UPDATE November 2024
I found that the Q strap holding the boot in place creates a perfect inlet for water thrown up from the front wheel, I replaced this with a better worm drive clamp and never had the problem again
In my opinion Q straps should never be used to hold a boot in place there is no radial pressure where the strap enters the ratchet head.

[egschade]

I'm replacing the mushroom vent with a banjo bolt/tube as has been recommended in various posts on this subject. I just checked mine and with 3K miles of mixed riding it was clogged. There was quite a vacuum when I opened the fill plug too. Draining the drive showed some evidence of water in the oil but it was not overly full.

Here's the link to a related thread: https://wildguzzi.com/forum/index.php?topic=96730.0

Here's what I ordered:
https://www.ebay.com/itm/Turbo-Oil-Feed-Banjo-Bolt-Kit-M10x1-5mm-for-SUBARU-IHI-VF30-VF35-VF37-1-5mm-Hole/153450384580?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

[Dirk_S]

Ah, right. Forgot the breather can clog up. I have the banjo bolt and hose ready to be fitted should that become an issue for me, but I’m holding off from doing it immediately in order to see if sealing the rubber boot indeed fixed my own water problem.

[twowheeladdict]

Makes you wonder how shaft bikes do water crossings.  Mmm. 

[Dirk_S]

Makes you wonder how shaft bikes do water crossings.  Mmm.

Dunno. Those consequential moments got edited out of the Charlie and Ewan videos in favor of more road spills.

[Bert Remington]

Several weeks ago I bought a quart of Motul synthetic 85W/140 for my 900 mile dealer service tomorrow.  Then I read malik's post https://wildguzzi.com/forum/index.php?topic=107379.msg1701379#msg1701379 recommending non-synthetic.  So I checked the owner and service manuals.  Both said synthetic for engine and gearbox but did NOT say synthetic for final drive.  Yesterday I bought a quart of Castrol 85W/140 which I will have the dealer use tomorrow.  Yeah I know the service intervals so don't bother reminding me.

[malik]

Veering slightly away from topic, but the manual doesn't call for final drive oil replacement at 600 miles, does it?  I was thinking not until 12,000.

When I bought the Classic new in 2010, I dropped the engine oil at 35km (shop to home). There was a lot of metal swarf clustered on the magnet as well as sparkling in the oil. Same thing at 599 & at 1,000km. Interesting. Over time and oil changes the amount (& size) of the metal on the magnets of the engine, gearbox & final drive gradually reduced. I conclude from this that when new there's a lot of sharp bits that are gradually smoothed with use. However,  given that most riders do not do so, and the engine, gearbox & final drive appear to last a long tome without problems, I'd hazard a guess & say the practice is of marginal utility - those moving parts appear to be built so as to cope with those bits of metal floating around.  Even so, changing the oils more frequently, especially in the early days, shouldn't hurt.

Back on topic - at 3,000 miles, the final drive seals should not be leaking. If there is not over much oil in there, it could possibly be a bad seal, and thus a warranty job. I've a mate with an older LeMans - it always leaked at the final drive. Several rebuilds & new seals didn't fix it for long, until he changed the final drive casing. It doesn't leak any more - likely the machining on the original casing was slightly off. Once every blue moon, something like this happens.

[malik]

Makes you wonder how shaft bikes do water crossings.  Mmm.

It seems the V85 has a hole at the bottom of the swingarm where the water usually collects, probably for just this purpose.  That bike is expected to venture into the less civilised byways. Greasing the whole of the drive shaft would seem to be a wise precaution.

I once was caught out in bulldust country with serious rain. When wet, bulldust turns into sticky clay, coats the tyres so there is no tread, and is scraped off by the mudguard and the swingarm. When I eventually removed the V7's swingarm, there was still the coarser particles of that bulldust living inside the swingarm, rust all along the shaft and the grease at uni joint and splines was still red from the dust. That clay had been squeezed past the boot into the swingarm. Next time this happens, I'll get on it a lot quicker.

[Solorider73]

My experience with water in the final drive, which happened often to me before sealing up the rubber boot, always resulted in leakage out from the breather. If this is radial, then methinks an overfilled system is just an add-on headache that’s not hard to remedy. Correct me if I’m wrong, but leakage from the hub screams of a bad seal.

I removed the rear plug after work today.  Oil looks good in level and color.  No grey or milky colors and I could see the oil level from the rear with a flash light and my finger. I don't think it's leaking much as it's hard to see with the poor lighting in my garage.  However in the bright sunlight I can see the streaks of dried oil coming from the hub.  I'm assuming a bad seal at this point.  I had already checked the vent bolt and it wasn't clogged.  Since it's still under warranty, I've made an appointment to have it checked.

I appreciated all the great feedback.  I will change the vent bolt to one of the suggestions above once I get the seal repaired.  I'll update when I get a result from the dealer.

[Solorider73]

Makes you wonder how shaft bikes do water crossings.  Mmm.

Great observation.  I going to breakout my Google fu and look up BMW GS rear drive leaks.  Seems they would have the most complaints given people actually take them off road.

[Solorider73]

Update:

Rear seal was leaking and replaced under warranty.  I rode it home which is around 100 miles with no leaks, so I'm happy with the result.  Hopefully this is the first and only rear seal leak for this bike.

[twowheeladdict]

Update:

Rear seal was leaking and replaced under warranty.  I rode it home which is around 100 miles with no leaks, so I'm happy with the result.  Hopefully this is the first and only rear seal leak for this bike.

Someone needs to update their signature.   

[Solorider73]

Done 

I took the V85 for it's 900 mile oil change and picked up the V7.

[Solorider73]

Update:

I have about 1000 miles on my V7 III Stone since the rear seals were replaced under warranty.  Last week after a ride, I noticed what looked like some oil on the rim, but it wasn't much and I wrote it off as road grime.  I took it out today for a 225 mile ride and yes it appears to be leaking rear drive oil again from the hub.  I checked the breather cap and it wasn't blocked or stuck.  I may go ahead and try the banjo bolt as was previously mentioned, but I don't have much faith in that being the issue.

I'm beginning to think the rear drive is just defective.   

[Bert Remington]

Solorider73 -- what lubricant are you using?  The non-synthetic Castrol 85W/140 I cited above is leak-free for my 2019 V7 III 3K miles.

I have a good multi-brand dealer but I do NOT let them choose fluids -- I provide them because that ensures I know what is used.  Everything else they provide because MG is pretty much their only choice.

[twowheeladdict]

   Bummer. Hope you can get a replacement easily.

[Solorider73]

Solorider73 -- what lubricant are you using?  The non-synthetic Castrol 85W/140 I cited above is leak-free for my 2019 V7 III 3K miles.

I have a good multi-brand dealer but I do NOT let them choose fluids -- I provide them because that ensures I know what is used.  Everything else they provide because MG is pretty much their only choice.

I don't know for sure since the dealer assembled it, but it did have Castrol on the ticket.

[Solorider73]

  Bummer. Hope you can get a replacement easily.

Yea, I'm going to try the banjo bolt and if it still leaks I will take it back to the dealer. 

[Bert Remington]

Castrol makes several 75W-140 gear oils that are synthetic which is popular these days.  The non-synthetic 85W-140 GL-5 is carried by O'Reilly among others.  And (MG content) it's cheaper.

[DaveJT]

Hate to be dim, but what exactly am I looking at in those photos? Is it weeping enough to cause a slippery tire, or a low level of oil?