V7 III strange noise when road is bumpy

[pedroalves]

Dear All,

My 2019 V7 III started to make a noise that sounds like a bang from two metal pieces hitting each other when I drive on rough surfaces like small speed bumps and cobblestone streets. So it's more when the road gives some type of vibration to the motorcycle that it happens. I tried already for several days to research here and other places (even asked GPT...) if someone had similar symptoms, but no luck so far. So far:

1) Some people here pointed to the side stand as the coil could become weak, and that was my first place to look at it. Everything was in place, the side stand need a bit of lubrification. The sound of the side stand hitting the frame was very similar to the sound I heard. So I put a piece of rubber gasket in between the side stand and the frame, I tested and no more metallic sound. Unfortunately, after a road test, the sound is still there, so probably not from the side stand hitting the frame.

2) Problems with the transmission? Back in early 2020, after I did my 900 mi (1500 km) service, I got a leak from the final drive that was repaired under warranty. I did drive probably 60 mi (100 km) before noticing the leakage, I wonder if some damage was done and if this is some symptom. I really doubt it because there is no relative movement between the final drive and the shaft. Will check the fluid and probably replace it (I replace it every time I replace the engine oil, did it myself at 10000, and 14000 km)

3) Shaft splines? The bike is now 9400 mi (15000 km) and I never lubed the splines connecting the shaft to the final drive, but again I don't see how the vibration could cause that "bang" at the splines. I will check for damage there anyway and lub it with MOS2 if it is OK.

4) U-joint? The U-joint effectively is affected and gets movement with the terrain irregularities, could this be the case? I think I also remove the swingarm and check it and lubed it, and also check the splines connecting to the gearbox.

5) Gearbox? Replaced the fluid at 14000 km with quality Motul 300 75W-90 (500 mL). Can something inside the gearbox be affected by the vibration and cause a sudden bang? Sometimes the bang also reminds me of the sound that shifting gears make (but stronger).

Any toughs? Despite this, the bike rides are amazing, everything feels good, and the engine seems very healthy (actually did an oil analysis to check, you can find it attached if you want to check).

Best,

[Dirk_S]

Is it one single <bang!>, or many at once, like a reciprocating <bang-bang-bang-bang>. If it’s reciprocating, is it very speedy, maybe with the speed of the engine?

How loud is the noise?

[pedroalves]

Is it one single <bang!>, or many at once, like a reciprocating <bang-bang-bang-bang>. If it’s reciprocating, is it very speedy, maybe with the speed of the engine?

How loud is the noise?

Hi,

Is a single "bang" at each portion of rough road. I think it may have a correlation with the engine being fully warmed, but I am not 100% sure of it.

thank you,

[Dirk_S]

If the noise isn’t consistent but instead relative to bumps, my brain leans toward your suspension or swingarm, as those moving parts are most affected by the terrain. But it could potentially be driveshaft as well.

Check your rear shock mounts, make sure the bushings haven’t come out of the eye mount at the top or bottom. Check that the shocks aren’t broken/leaking. Make sure they’re going up and down properly.

Maybe the front forks are bottoming out? Any oil residue on the stanchions?

Take a look at the swingarm—are the pivot pins securing the swingarm properly in the recesses of the gearbox? Anything broke/cracked around there?

Check that u-joint when you pull out the driveshaft, make sure it rotates freely and not seized.

Check that your connecting bolts are secure—like the engine through-bolts, exhaust flanges; maybe give the exhaust pipes a shake / jerk, and see if they feel loose.

Maybe a horn is hitting something, or fork brace…or mudguard is loose…

[Zenermaniac]

May be the floating brake disc? I sometimes get noise from mine.

[elrealistico]

Exhaust heat shield is loose

[Zenermaniac]

Exhaust heat shield is loose

Yep. That happened to me with my V9. At a certain rpm it sounded like I had a serious clutch rattle or something bad happening. I found 1 screw loose on the right front of the exhaust heat shield when I was cleaning the bike. Tightened it up and all was well again. Who’da thunk.

[Cam3512]

Loose headers?  Horn bouncing against something?

[guzzisteve]

Yes, those thingamabobs come loose every so often .

[Huzo]

Jeez let me think…
Did you try approaching the bumps, then  pulling the clutch and killing the engine, so traversing the bumps with the engine off ?
That will immediately tell you if it has anything to do with the reciprocating masses in the engine ?
Are the forks topping or bottoming out ?
Rear shocks doing similar ?
Front guard mount loose ?
Rear shock mounts missing rubber bushes ?
Tank loose ?
Exhaust components loose ?
Either front or rear caliper pads “knocking off” ? (Trail a tiny bit of brake over the bumps and see if it goes away.)
What happens if you get a few mates around and shake the living guts out of it ?

[faffi]

Huzo summerized the suggestions nicely and added a couple of interestring ones.

[John A]

Slapping the muffler sharply can reproduce a rattle. The liscence plate can rattle over bumps as well

[Brand X]

May be the floating brake disc? I sometimes get noise from mine.

I would put my money on that one..See how loose your disk is..Grab some brake when it happens, and it that will tell you if that is the noise coming from there.

[Muzz]

Baffle come loose in the can?

[Huzo]

May be the floating brake disc? I sometimes get noise from mine.

Pretty easy to check that one.
Just hold a bit of brake on, over the bumps.

[chuck peterson]

On a v7, one of my headpipes lost a weld right near the crossover.

Using a BFH (Big Feffing Hammer) rubber mallet i walk around tapping different parts of the bike with the rubber side…

Tap…

Tap…

Tap, buzz

Tap, buzzz

There it is…

[pedroalves]

UPDATE:

I looked everywhere for loose stuff, nothing... As I said previously it's like a metallic bang that is triggered when the bumps have a certain frequency.

But I discovered something, and is not good news. I don't know if this is somehow related to the bang, but is bad:











My final drive gears are disintegrating with only 17000km. The final drive oil was changed at 3235 km (oil seal leak under warranty, 5/2/2020); at 10000 km (31/10/2021), and the last time at 14653 km (5/1/2023).

This issue seems linked to the previous oil leak at 3235 km, covered under warranty, which seemingly only addressed the replacement of the two seals and the hub gasket. No action was taken concerning the gears, a significant oversight in my opinion.

If gears lose oil, they lose lubrication and cooling capabilities, resulting in premature wear and irreversible damage. This explains the current situation, where after 17,000 km, a gear is disintegrating through the hub plug.

Despite the warranty being over almost 2 years now I think this is Moto Guzzi responsibility, the final drive oil was changed almost every 5000km (1/4 of the recommended mileage, 20000km), and the fact that when I had the broken seal they only replaced the seals and gasket (I asked this week for the repair report, back in 2020 they didn't give anything to me).

So now I will wait some days for an answer from the Moto Guzzi Portugal and Piaggio Customer Service (Headquarters), and decide what to do next. One thing I know now is that the final drive needs to be replaced.

[pedroalves]

Update:

So the dealer as expected refused any responsibility and said that if I wanted they could look at the motorcycle and charge for the repair. No thanks. I disassembled the rear drive, and I found this:













The explanation I have is that when the motorbike had the seal failure around 3000km they replaced both seals, to replace the bigger one on the wheel side they needed to remove the crown wheel. When reinstalling probably the torque wrench was in an uncertain part or it was after lunch and the red wine gives you wings, who knows? The thing is that I had a snapped bolt inside the case hitting everything inside. I think I was actually lucky I could had an accident due to some wheel block or something.

I already asked them again if this is their (dealer and Moto Guzzi Portugal, same people) final position about this situation. If it is I will make a formal complaint to Moto Guzzi International and my lawyer will reach to the dealer.

I find this truly sad and are things like this that give a bad name to a brand, unprofessional mechanics, and greedy dealers.

[Dirk_S]

Really sorry to see that and relieved it didn’t cause the wheel to lock up. Pretty disappointing that the dealer isn’t taking this seriously. Seems to me it’s either the bolt manufacturer or the dealer to blame here.

[Pescatore]

That's unfortunate and lucky it didn't lock up while riding.
The gear seems fine.  Is the pinion OK?
Lawyer up. Hopefully it's resolved quickly.

[John A]

I was a service manager at a large Japanese mc dealer one summer when aviation dried up because of the oil embargo. A polite customer could get warranty coverage on things I couldn’t sometimes. After being turned down , I would ask the customer to contact customer service with the instructions not to fail the personality test as they plead their case with logical persistence. I persuaded Guzzi to cover a blown ujoint carrier bearing that destroyed the swing arm a few months after the warranty was over on a Cal 2 that I bought new, and the dealer was denied. It was worth the call!

[pedroalves]

UPDATE (another)

So yesterday I went to disassemble further the rear drive, and I was wrong the bolt didn't break because of excessive torque upon assembly when the bike had the seal leak.

Actually... all bolts were loose... I was able to unscrew all of them with just my fingers, even the one that broke.

Again, even if the over-torquing mistake is ruled out, I think we still have a serious error here. Some possibilities:
1) Under-torque;
2) Thread locker contamination with oil (improper cleaning)
3) No thread locker at all;

Here is a picture of the removed bolts:




I don't see any sign of a thread locker (I think there must be a red thread locker in those).

Here in the case bolts, it had some residue of red thread locker (I think from the factory assembly):




I noticed that in previous models those Allen bolts had Schnorr washers or locking plates, in the exploit view for the V7III I don't see any of those, so I guess a red (high strength) thread locker must be applied.

[faffi]

Hopefully, your dealer/importer will accept their error and replace the damaged parts. The most important thing is that you did not have an accident, though