Transmission leak - please advise

[Scud]

From what I can surmise, the leak is from one or both of the rear seals. It only migrates down the left side, not the right. It's definitely gear oil.

 

After looking at the shop manual, removing the rear cover looks simple, but removing the thin case that goes to the main case appears to require several special tools to remove several gears.

 

So... anybody been into one of these? Maybe somebody has the special tools that I could borrow? Or is this job for a professional? The orange silicone seems to be a problem - maybe Threebond 1211 would be better?

 

 

Not what I was hoping to find... 

[gstallons]

IDK what threebond 1211 is ? Loctite gasket eliminator is THE best thing I have used .

[JBBenson]

Leaks are tricky, they can migrate from where they started. Are you sure its not leaking from the splined shaft in the left of the photo? Is that the shift lever input? I am trying to orient myself.

 

In any case, for anaerobic flange sealing, try Loctite 518. 

[Chuck]

Scud, I'm having a hard time deciding what is leaking. It seems strange to me that it is on top.

[Scud]

Threebond is like Yamabond. Pete Roper mentioned it as his sealant of choice. There's a white, slow-drying (1211) and a grey, more tacky, quick-drying (1184). I think the 1211 and Loctite 518 are equivalent products.

 

Here's a labeled version to help with orientation/discussion. The oil was all hiding behind the starter, shock reservoir etc. - and dripping onto the crossover, so I didn't notice it until I removed all that stuff. If I was clever, I would have found it earlier, cleaned it, and done some foot-powder leak-sleuthing. I'm pretty sure that it is not leaking from the pre-selector cover.

 

 

And here's the diagram that shows how the cases go together (other pages show all the gears and bearings)

 

 

A leak at label 1 in the diagram would be pretty easy to address.

But a leak at label 2 requires almost a full tear-down of the tranny and several special tools to remove gears between part numbers 2 and 3.

 

I thought my 12,000 mile service would be a "major" one due to clutch replacement.  I already planned to remove the pre-selector for a rebuild/improvement but this takes it to a whole new level of "major."

 

[kglm]

http://www.henkel-adhesives.co.uk/2838_UKE_HTML.htm?nodeid=8797713235969
 
I use this  , now 100 000km after fix.  
 
... home made special tools 01912530 is what you need, - i open the box just using normal tools ...
 
-KG-

[docc]

I hate to come in raining on the parade, but the frame mounts have been seen to crack and weep.

 

With the crinkle pint, it would be very hard to see, so some paint removal and careful inspection of the mount bosses would be in order . . .

[Rolf Halvorsen]

I have both the 2 special tools that you need to unscrew the special nuts thats hold the axels.

 

Since I live in Norway - it would be best if users in USA would buy them. And a warning - they are not cheap, but are the best money can buy.

 

Send me a mail and I will respond with pictures and prices. (I also have tools for the 5-speed gearboxes.)

 

I am sure that there are people in this forum that knows my tools and will report in.

 

rolf.halvorsen@mail.com

[Chuck]

I hate to come in raining on the parade, but the frame mounts have been seen to crack and weep.

 

With the crinkle pint, it would be very hard to see, so some paint removal and careful inspection of the mount bosses would be in order . . .

 

Hmm. That *could* explain the leak being on top. I'd not heard of that one..

[Scud]

OK - the pre-selector and the rear cover can be removed with "normal tools" - but special tools are required for removing the cast part #2 in the above parts diagram. I think the shop manual references 7 special tools for use on the transmission. It would be nice to have a "community" set that we could shuffle around. The tools are expensive from Moto Guzzi.

 

Rolf, do you make and sell these tools, or do you have the MG tools?

 

The crinkle paint is really thick, difficult to clean, and yes, it would probably obscure a crack (if there is one). Don't worry about raining on the parade. I only want to fix this once - so all information is potentially useful.

 

I suppose the next step is to remove the two "easy" covers, strip the paint, and re-assess. Oh sad day, the Scura's gonna be out of service for a while...

[docc]

I suppose I would start with the paint strip and inspect the mounting bosses first.

 

I know of two gearboxes that cracked there (mine included) and the leak does exactly as you see.

 

For reinforcement, I added the center frame support to my V11 that was eliminated after the Sport 1100 (not sure if any of the injected bikes got them ?) It certainly makes sense to support the engine/gearbox in three places instead of just the very front and very back.

 

"Piastra Colleg":

http://www.v11lemans.com/forums/index.php?showtopic=1797&p=17967

[Scud]

 i open the box just using normal tools ...

 

 

But the shop manual shows restraining ring nuts (Labeled I and L) require a special tool. How do you remove these?

 

[Rolf Halvorsen]

My tools are much better than Moto Guzzi ever have made. They are professionally produced after my design - and since I have been working with Guzzi for 20 years and have worked with technical design connected with rocket motors - I sure can say I have relewant background.

 

You need only 2 of my 7 tools to open the 3 special nuts. 

[Rolf Halvorsen]

Here are 4 of my special tools for Moto Guzzi

 

[Rolf Halvorsen]

I am sorry about the quality of the attached picture. I am too old for this computer world.

 

Rolf