• 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!
  • 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.
  • 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.
  • Like the new V100, GuzziTech is full throttle into the future! We're now running on an all-new server and we've updated our Forum software. The visual differences are obvious, but hopefully you'll notice the super-fast speed. If you notice any glitches or have any issues, please post on the Site Support section at the bottom. If you haven't yet, please upgrade your account which is covered in the Site Support section or via the DONATE tab above, which gives you full site access including the DOWNLOADS section. We really appreciate every $ and your support to keep this site ad-free. Create an account, sign in, upgrade your account, and enjoy. See you on the road in 2024.

Breva 750 Gearbox noise.

dbeerd

dbeerd

Tuned and Synch'ed
Joined
Mar 15, 2010
Messages
38
Location
South Africa
I noticed that there have been many posts in connection with the 5th gear whine re the Breva 750 gearbox. My Breva is unfortunately inflected with the same symptoms. I have just removed the box and I am on the point of opening it up. I surmise that I will find the 5th gear cluster pitted. The bike has 30.000 km on the clock. It would be quite simple to just replace the faulty parts with new ones. However I see myself redoing this procedure every 30.000 km’s. I surmise that this is a design / quality control issue. Does anyone know if this issue has been corrected? Will the new gears be harder than the original set? Can I Nicasil the gear pair? A any help will be appreciated. :?:
 
dbeerd said:
I noticed that there have been many posts in connection with the 5th gear whine re the Breva 750 gearbox. My Breva is unfortunately inflected with the same symptoms. I have just removed the box and I am on the point of opening it up. I surmise that I will find the 5th gear cluster pitted. The bike has 30.000 km on the clock. It would be quite simple to just replace the faulty parts with new ones. However I see myself redoing this procedure every 30.000 km’s. I surmise that this is a design / quality control issue. Does anyone know if this issue has been corrected? Will the new gears be harder than the original set? Can I Nicasil the gear pair? A any help will be appreciated. :?:
Click to expand...

I'm not aware of the noise issue being corrected, but people seem to have learned to live with it (the noise). The gearbox should still last a long time, even while making the noise. Remember it has straight cut gears, not the helical gears like in the big blocks.

Make sure there is at least one litre of oil in it. Don't believe the level hole. Fill it up on the side stand and measure in a litre or even a bit more. At some point Moto Guzzi reduced the amount to avoid spraying oil out through the breather, but I've put a bit over a litre in mine and the newer boxes like the Breva 750 have a different breather that does a better of of keeping the oil in. Mine seems to anyway.

FWIW my Breva 750 has 43000 km on it and does whine a little in all gears. I have no intention of pulling the gearbox out for a long time yet.
 
I have no idea if you can do this or do that, but;
I can hear the whine in 5th even though wearing earplugs. It has always been like that, and it doesn't worry me, as it hasn't been neither worse nor better throughout the present 60000 kms done.
Has your gearbox whine increased? There may be some quality issues; I know of two Breva-gearboxes which have failed totally, both known from here - or maybe the mild side. Otherwise the basic construction is as old as the smallblocks, and if that construction itself was bad it should be very well known by now.
If you decide to dig up the gearbox, please keep us informed!
 
I haven't noticed a 5th gear whine in the V7C, and I don't think there have been any changes to the transmission since the Breva design.
When I'm out tomorrow, I'll pay attention.

I've heard of others who have reduced or eliminated tranny noises by changing to a specialty oil, like a Redline product. Others have found no help in that, or that the change was short lived.

Joe
 
Hi, Thanks for the comments, much appreciated. There is no way that I can live with this noise. It has worsened over the last 5000 Kms. I already have that box out and found an oil leak coming from the crank end seal. I tried overfilling the box, but to no avail. I just need to find the time to machine up the tools to hold the clutch spline and main nut so that I may get the bell housing off.
 
dbeerd said:
Hi, Thanks for the comments, much appreciated. There is no way that I can live with this noise. It has worsened over the last 5000 Kms. I already have that box out and found an oil leak coming from the crank end seal. I tried overfilling the box, but to no avail. I just need to find the time to machine up the tools to hold the clutch spline and main nut so that I may get the bell housing off.
Click to expand...

I'd be interested to see pics of the gears you pull out.
 
Hi All, Just finished making the tools to remove the main nut in the bell housing. I made them out of normal thick mild steel flat bar thinking that that would suffice. Was I mistaken!!!!!!!!!!!!!!!! The tool that holds the clutch spline is bending. Cant believe it. I will have to reinforce the tool tomorrow. I surmise that this is a left hand thread? :sick:
 

Attachments

  • tools.jpg
    tools.jpg
    338.1 KB · Views: 839
Hi All, Managed to get the nut lose. Firstly I had to reinforce my homemade spanner. Looks as if a serious grade of lock tight was used. What I did was to heat up the nut and then use a special tool called a hammer to assist the spanner. One hard smack and it was lose.
 

Attachments

  • Nut_removal.JPG
    Nut_removal.JPG
    29.5 KB · Views: 492
Not a happy chap, this is the iron filings that I found stuck to the bottom of the gearbox (inside the casing) obviously this does not come out during a routine oil change
 

Attachments

  • Inside_box.JPG
    Inside_box.JPG
    135.8 KB · Views: 826
Look at the damage to the various gears. How now??????????
 

Attachments

  • Worn_Gears.JPG
    Worn_Gears.JPG
    173.1 KB · Views: 844
I can’t believe that the hardening was done correctly on these gears. Just about every gear has damage to it and this at 30000 Km/s. As we have no authorized dealer in South Africa I personally did all the servicing myself and I have been meticulous about the servicing. I cant believe that any QC is performed during the gearbox build stage. I wonder if Guzzi subcontract out the machining of the gears? If you take a careful look at the gears you will still see manufacturing marks on some of the gear teeth.
 
I can see the pitting, as I think it is, and I can agree in your conclusions.
Are Guzzis "grey" imports to SA, since you have no dealer? No idea to claim warranty, I guess. :dry:

Seems that there are smallblock gearboxes parted out occasionally, mainly in the US, but you can try Teo Lamers in Holland. Also British Moto-Bins do sell used parts, AFAK.
 
Thanks for the info. The problem with Guzzi in SA is that I think that they withdrew during the sanction years and then recently, about 5 years ago re-launched their bikes locally. I of course always wanted a Guzzi and jumped at the chance to own one. Hence I purchased a brand new Breva from an authorized dealer. I only managed to get my service book stamped once by them before they withdrew from the country due to poor sales. Every single part that I need for the bike comes in from overseas. With the ongoing state of the Rand (our currency) I find myself paying 15 times more for any part compared to someone in Europe. Then I still need to pay transport into Africa that costs as much as the parts that I purchased. The chaps with the Jap bikes don’t have that issue as all the brands are well represented. The last hour or so I have been toying with the idea of TIG’ing (If there is such a word) up the worn areas on the gears and then cutting them back to shape with a gear cutter on a lathe. Obviously I would have to case harden the gear afterwards. I have a friend that builds Formula M race cars that has the correct CNC equipment and will be seeing him tomorrow to discuss the possibility of doing this.
 
dbeerd said:
Look at the damage to the various gears. How now??????????
Click to expand...

Dion, that is one scary picture :shock: . I hope your gears were making a lot more noise than mine are...
 
You must log in or register to reply here.
Back
Top