Shaft drive slack question?

[Guest]

Bike is a 650GL, it has a knocking noise I'm pretty sure is in the transmission. Sounds like gears taking up slack, even at idle. If I run it on the center stand In gear I can hear it. If I load up the drive train, it goes away.

Question is, if the bike is on the center stand and in gear, not running, how much should the tire be able to rotate by hand until initial resistance is met?

Once it is met how much further should it go? It feels like it meets spring resistance and then springs are compressed.

And looking into the oil fill at the clutch, should the clutch basket "wobble" as the gears are loaded and unloaded by rotating the tire by hand?


Any help or comparison to any shafty would be much appreciated.

[Old guy]

I'll try to get some videos up

[GSX1000E]

Slack in a shaft-driven bike usually means that the secondary drive bearings are shot. I am not real familiar with the 650G but in the bigger bikes, it is located by the shifter.

[Old guy]

We'll........ Can the case be split without pulling the cylinders/head, etc??

[Nessism]

The nut backs off the secondary gear driveshaft flange, then the gear breaks. I'd check this right away. The bearings themselves rarely fail. http://members.dslextreme.com/users/...pair_zooks.pdf

[Old guy]

When I grab the shift lever arm coming out of the cover I can feel a catch/tick in it.

Even out of gear the noise/knock/tick is still there. When running on the center stand it seems to be worse in 3rd gear.

[Old guy]

Thanks, I'll have to check that.

Would that cause excessive play/looseness/backlash in the whole gear box?

It sounds like the gearbox is loading and unloading each time the engine fires. It does it even in neutral, I was thinking maybe it was the main drive gear from the crank to the ??clutch drive gear??

[Nessism]

Could be a lot of things including the clutch basket. Hope it doesn't turn out to be serious.

[Old guy]

I might look for a spare motor and just hoon this one until breaks or winter rolls around again.

[Old guy]

Reasonably sure it's not the clutch basket. Had the cover off several times.

Oh, and BTW, RVT does seal cases. I'm not buying case gaskets again or cutting them out of cereal boxes again.

[JTGS850GL]

Reasonably sure it's not the clutch basket. Had the cover off several times.

Oh, and BTW, RVT does seal cases. I'm not buying case gaskets again or cutting them out of cereal boxes again.

BTW.. RTV also ends up in your oil and can plug critical oil passages.

[49er]

BTW.. RTV also ends up in your oil and can plug critical oil passages.

Be careful with RTV.

Some engine covers require the gasket thickness to achieve the correct clearances. The tacho drive gears on some GS models bind when thinner or "Real Gaskets" are fitted instead of the stock gasket.

[tom203]

So the noise/tick is in all gears-how about if you pull clutch lever in?


Edit; just checked- bike in 1st,on centerstand - maybe 2 inches total of back and forth travel at rear wheel before resistance

[Old guy]

On the RVT. I've worked on a lot of modern engines, most have gotten away from gaskets.

On the rare occasion you'll see an RTV mishap, it's going to be caused by operator error. Including like was mentioned, not accounting for necessary clearances.

There are a couple of suitable "silicones" for sealing cases, the biggest factor is technique, the second, the right sealant.

The best sealant by far is grey Permatex. It is used by multiple OEMs, or some variation of the grey Permatex. It is also called assembly adhesive. It sticks parts together really well. So when you go to split the case/cover again, be aware, it's going to be tougher. It's like gorilla snot, so breaking off and floating away to the pickup screen isn't really an issue. If you think cleaning RTV off a surface sucks, grey is 10 times worse.

The black Permatex isn't as adhesive, and will work fine as long as it's not gooped on.

The main goal with RTV is to fill the gaps and irregularities between the mating surfaces, and as long as the two are stabilized on along the common plane with dowl pins or bushings, the sheer strength and flexibility of the sealant is less of an issue. So, the voids and irregularities between two machined surfaces are very very small so only a very small amount of sealant will be needed.

The greater the adhesive properties of the sealant the better any squeeze out will adhere to it self and the surfaces it contacts, also the less mass the squeeze out the less adhesion it needs to stay put. Technique minimizes or can eliminate squeeze out all together.

2mm is about all you need no matter how wide the surfaces are that need to be sealed as long as they are machined surfaces, less is sometimes better if you can squeeze hard enough to use a hole that small.

the instructions on almost all RTV say to apply a small bead, allow for it to partially set up, assemble parts LIGHTLY, allow to cure further, THEN torque the parts down. So about 15 or more from the time the parts get lightly assembled until torqued down. This is the most important part of not f'ing things up with RTV. Do this and you'll see very little squeeze out, if you start seeing it happen, walk away and finish tightening it later. As long as the parts are put together while the silicone is partially cured and adhesion occurs on both parts, you're good to go, even if you allow it fully cure before torquing it down. Even if you didn't get 100% adhesion on both parts before the sealant cured, the gaps will seal with the compression from the torque.

That's my bit on using sealant.

[Old guy]

So the noise/tick is in all gears-how about if you pull clutch lever in?


Edit; just checked- bike in 1st,on centerstand - maybe 2 inches total of back and forth travel at rear wheel before resistance

Thanks for checking. I'll try to get a video today. The noise is concerning.