V85tt Final Drive leaking

[Grabcon]

I know this topic has been kind of discussed but I am creating a new post as to not muck up someone else's thread.

Bike is a 2020 V85TT, approximately 15000 miles. This is my first Moto Guzzi so I am still learning about them. I typically do all of my own wrenching. This is one reason I bought a V85TT it is a simple machine compared to most out there.

Condition is leaky final drive, oil/gear lube collects around drain plug on final drive. I have change the lube 3 times, I know it is more than required , but it is simple and inexpensive. Each time I replaced with that the manuals recommended 180cc's. And have not had any issues. Now that I found the leak I did some google research and found that there was a service bulletin issued that changes the amount of lube to 160cc's.

Where I am at this time.
I have drained the lube and it measured about 175cc's after 1000 miles or so. I let it fully drain and replaced with fresh lube 160cc's. I have pulled the rear wheel and everything is dry in and around and behind the Cush drive. I cleaned up all residual lube on the final drive and drive shaft housing. There seemed to be oil collection at the weep hole on the drive shaft housing.

Made sure everything was dry and went for a 50 mile ride. There was more lube collecting but not like I saw originally. I will clean up and test agin today, could be just some residual lube on the inside of the drive shaft  and final drive connection.

In my opinion the vent did not leak anything but I don't know if it is venting or not. I believe it is the seal on the front of the final drive. So here are some questions below.

Can the final drive housing and the drive shaft housing be separated at the flange joint and put back together without removing the drive shaft/swing arm housing from the bike?  I would like to inspect and clean the inside.

The service manual is somewhat confusing but can the seal on the input shaft to the final drive be replaced without removing the pinion nut?

I don't have any Moto Guzzi specific tools so there are limitations on what I can disassemble and get back together.

Here is the rub. My wife and I are leaving on a 6000 mile motorcycle trip on June 7th. I need to get this resolved with confidence before we leave. I am 200 m miles from the nearest worthy MG shop. I also don't know if they have parts or schedule to fit my timeline.

[rocker59]

Condition is leaky final drive, oil/gear lube collects around drain plug on final drive. 

Have you replaced the washer on the drain plug bolt?  They're intended to be replaced regularly and will weep if reused several times.

[Antiquar]

In my opinion the vent did not leak anything but I don't know if it is venting or not.

Checking the operation of the vent would be a good thing. A clogged vent would cause oil expulsion. Should be fairly easy to do as well.

[Grabcon]

Have you replaced the washer on the drain plug bolt?  They're intended to be replaced regularly and will weep if reused several times.

I have not.

[kingoffleece]

160 is the amount.  The published 180 has been superseded by 160.

[John A]

When I put in the drain or level plug it helps to start the plug and spray it off with mineral spirits before you wind it in. Otherwise you get a slight oil stain around the plug. It’s minor but helps you see the amount that it may seep. Mineral spirits is fairly inert and won’t hurt paint or rubber. Cheap too…

[Snowman]

Replace the washer. If you have re-used it sevaral times and that is the area where the oil is.

[bigbikerrick]

Grabcon,you need to clean up the final drive and inspect exactly where it is seeping from. If the housing is black, and hard to see where it originates, you can use some spray foot powder after cleaning the area up, spray the housing as if you are spray painting it, then take it for a spin, and recheck for seepage.
I see you are in Hereford, we are almost " neighbors". I am down in Douglas.
Rick D.

[Tkelly]

Had a leak from the fill plug on my Stelvio,a new crush washer solved the problem.

[Grabcon]

So after today's ride things have improved. Now that the correct amount of lube is in the drive plus a few hundred miles  the residue has become less each time I ride. I am positive the drain plug is not leaking. I believe that the lube was /is coming from the weep hole in the drive shaft housing. Each time I ride the residue is less and less.
 No lube on rim or tire.

Now I am in monitor mode, check each time I ride and proceed from there. If it worsens I most likely will take the car on our trip

[Grabcon]

The verdict is in. I will see you on the road. The car is staying home.

Today is oil & filter change day on both bikes before our big trip. Hope to meet some of you up in John Day or maybe Redmond too.