• Ciao Guest - You’ve landed at the ultimate Guzzi site. NEW FORUM REGISTRATIONS REQUIRE EMAIL ACTIVATION - CHECK YOUR SPAM FOLDER - Use the CONTACT above if you need help. New to the forum? For all new members, we require ONE post in the Introductions section at the bottom, in order to post in most of the other sections. ALWAYS TRY A SEARCH BEFORE STARTING A NEW TOPIC - Most questions you may have, have likely been already answered. DON'T BE A DRIVE-BY POSTER: As a common courtesy, check back in and reply within 24 hours, or your post will be deleted. Note there's decades of heavily experienced Guzzi professionals on this site, all whom happily give endless amounts of their VALUABLE time for free; BE COURTEOUS AND RESPECTFUL!
  • Be sure to see the GTM STORE link also above for our 700+ product inventory, including OEM parts and many of our 100% Made-in-SoCal-USA GTM products and engine kits. In SoCal? Click the SERVICE tab above for the best in service, tires, tuning and installation of our products or custom work, and don't miss our GT MotoCycles® (not) art on the BUILDS tab above. WE'RE HERE ONLINE ONLY - NO PHONE CALLS MADE OR RECEIVED - DO NOT EMAIL AND ASK QUESTIONS OR ASK TO CALL YOU.
  • There is ZERO tolerance on personal attacks and ANY HYPERLINKS to PRODUCT(S) or other competing website(s), including personal pages, social media or other Forums. This ALSO INCLUDES ECU DIAGnostic software, questions and mapping. We work very hard to offer commercially supported products and to keep info relevant here. First offense is a note, second is a warning, third time will get you banned from the site. We don't have the time to chase repeat (and ignorant) offenders. This is NOT a social media platform; It's an ad-free, privately funded website, in small help with user donations. Be sure to see the GTM STORE link above; ALL product purchases help support the site, or you can upgrade your Forum profile or DONATE via the link above.

Transmission Cage Breather Leak

Sean_Kelly

Sean_Kelly

Tuned and Synch'ed
Joined
Nov 17, 2016
Messages
38
Reaction score
34
Location
Riverside, CA
Has anyone else experienced an issue like this? It seems like whenever the temperature rises (SoCal heat cutting through traffic) or if I push the bike too long in 6th doing 90ish I get a leak from the transmission housing breather plug.

This is the plug I'm talking about:
MotoGuzziBreather.webp
Any idea what could be causing this? Kinda a pain to have to clean up the engine so often.
 
Yep, remove and clean/blow out with air and re-install. Should fix your issue if the trans isn't overfilled (which happens more often than not, even at a dealer).
 
Are you using a synthetic gear oil? They tend to be thinner while giving excellent lubrication and not as prone to expansion when hot like mineral oils. I have a preference for Mobil 1 gear oils, but it is up to you. Also check the oil level for over fill. With the big block 5 speeds I put in 50cc less than the specified 750cc to reduce pressure build up in the gearbox.
 
GT-Rx® said:
Yep, remove and clean/blow out with air and re-install. Should fix your issue if the trans isn't overfilled (which happens more often than not, even at a dealer).
Click to expand...

Cool, thanks Todd. I'll give that a try when I get home today.

john zibell said:
Are you using a synthetic gear oil? They tend to be thinner while giving excellent lubrication and not as prone to expansion when hot like mineral oils. I have a preference for Mobil 1 gear oils, but it is up to you. Also check the oil level for over fill. With the big block 5 speeds I put in 50cc less than the specified 750cc to reduce pressure build up in the gearbox.
Click to expand...

Thanks for the info John. Haven't done a gear oil change yet myself (I think that's coming up at my next planned maintenance) But I'll keep this in mind when I buy supplies. I think the cc amounts were different between 6spd and 5spd as well.
 
Sean_Kelly said:
I think the cc amounts were different between 6spd and 5spd as well.
Click to expand...
Indeed, which is yet another issue by most shops/dealers.
5-spds are 1L (950 is what I use)
6-spds are 500ml (450 is what I use)
 
Sean, I have a 6 speed V7ii, and the bike has done it twice, both times pushing to 90 mph for an hour or so. Now I'm not sure yet if it makes a difference, but the bikes was being ridden through significant elevation changes. Bloody mess.

Now, I had done the first service prior, and added exactly 500ml (6 speed) prior. I have since serviced it again, and this time added about 450 ml. I will report back if it does it again. If it does, then the breather will be modified.
 
Took the breather off on Sunday and blew it out as suggested to get it ready for my Monday commute. The traffic was a little more open than usual this morning with cars doing 80-90, so I was doing roughly the same. About halfway through the ride I could smell the transmission fluid. Sure enough, when I got to work it was dripping down the case again.

Looks like I may have to adjust the fluid levels. It just strikes me as odd since the issue didn't really start until around 5000 miles.
 
Drain it out into a measuring cup and see how much is in there. Did you service it yourself?
 
jpv7 said:
Drain it out into a measuring cup and see how much is in there. Did you service it yourself?
Click to expand...

First service I took it to Todd's shop, 2nd service I did myself but did not change the gear oil. If I recall correctly from the manual shouldn't it not need to be changed until 12,400 miles?
 
Just thought I'd give a quick update:

I tried to alter my riding style a bit on Friday since I noticed the issue seems to only happen in 6th gear at high speed.
On my way home I kept it in 5th gear much longer (into the mid 6k rpm range) and did not shift into 6th until about 90mph and only on flat or downhill stretches. Previously I had been shifting into 6th at about 5700rpm or so and about 85ish. This seemed to do the trick, as I got home on another hot day and there was no fluid spillage on the case this time!

Hopefully posting this will help others out with this issue.
 
Sean_Kelly said:
Just thought I'd give a quick update:

I tried to alter my riding style a bit on Friday since I noticed the issue seems to only happen in 6th gear at high speed.
On my way home I kept it in 5th gear much longer (into the mid 6k rpm range) and did not shift into 6th until about 90mph and only on flat or downhill stretches. Previously I had been shifting into 6th at about 5700rpm or so and about 85ish. This seemed to do the trick, as I got home on another hot day and there was no fluid spillage on the case this time!

Hopefully posting this will help others out with this issue.
Click to expand...


This is curious. Since this is a constant mesh gearbox, all gears are turning at the same time. By using a lower gear more, the input shaft speed is increased for any output shaft speed to reach the desired mph. So for a given MPH, the output shaft will match the required RPM to deliver that speed. All that really changes is engine RPM, input shaft RPM, and lay shaft RPM. That is with two shafts turning faster for a given mph, you would think it would pump more, not less. Perhaps your gearbox has reached its desired oil level.
 
Sean_Kelly said:
Just thought I'd give a quick update:

I tried to alter my riding style a bit on Friday since I noticed the issue seems to only happen in 6th gear at high speed.
On my way home I kept it in 5th gear much longer (into the mid 6k rpm range) and did not shift into 6th until about 90mph and only on flat or downhill stretches. Previously I had been shifting into 6th at about 5700rpm or so and about 85ish. This seemed to do the trick, as I got home on another hot day and there was no fluid spillage on the case this time!

Hopefully posting this will help others out with this issue.
Click to expand...
I'm gonna ride my bike the way I want...if it pukes oil, then something is wrong with it (assuming the level is correct).
 
You must log in or register to reply here.
Back
Top