Bad grinding/crunching sound

[wildbonz]

Hi. I rode about 75 miles yesterday. It ran great all day, and we were into a bit of everything. We were going across a lake on the way home, about 70-80 mph. It slipped and revved up like a belt blew. I let off throttle, then it re-engaged. I kept going another mile or so and it did it again. Only for about a second each time. I slowed down to 50ish and then it started feeling worse. I thought maybe the belt was coming apart. I stopped and then when I tried to move ahead, it would, but there was a bad grinding noise.
I took off the covers, and the belt was fine. There was no obvious sign of anything wrong. Tried another belt, same thing.
Towed it back the rest of the way. Put it on the trailer, ran it without the belt for a test, revved it and the clutch seemed to work properly. No grinding, clutch looked to operating properly. Put the belt back on and as soon as it engages, there is the bad sound again, in forward or reverse.
The sheaves do seem a bit wider than normal...maybe. The belt sits right down and has some wiggle room. Is it a bad bushing, maybe?
After removing the clutch, it looks OK, and the motor side looks good, no apparent problems there.
I need help. The clutch is off, and I need help to know where to start.

06 Attak. Drag n Flys. About 3300 miles. Well maintained.

Thanks

I also posted this in the engine/clutching section.

 

[snowbeast]

You have a chaincase problem,re3move your panels,and the bottom of the bellypan,either drain fluid,or catch it when you remove the cover. If you have never removed the cover,than get a manual,or ask on here,it can get preety deep,if you have mechanic skills,it wont be to bad,thats where i would look. good luck.

 

[Irv]

You have a chaincase problem,re3move your panels,and the bottom of the bellypan,either drain fluid,or catch it when you remove the cover. If you have never removed the cover,than get a manual,or ask on here,it can get preety deep,if you have mechanic skills,it wont be to bad,thats where i would look. good luck.

X2 on the chain case, 1st place I would look.

Also, in the future never run your machine with the belt off, especially reving it up and such as it can do serious damage to your clutches.

Good luck and be sure to post what you find.

 

[wildbonz]

Thanks. We thought chaincase but it sounded like the clutch side.
With the belt off I started it, revved just enough to see if the sheaves would come together. No more than 3 seconds total, key on to key off and 5-6000 rpm. But yeah, I won't do that again, I was worried and frustrated.
Thanks.j

 

[NY AttakGT]

Kinda sounds like what I experienced when the chain tensioner post (that the tensioner swivels on) inside my chain chase broke off. God awful sound!! Alot of damage inside...chain case, chain, and both gears were changed under YES warranty.

 

[APEX 06]

Or a bearing.

 

[doc 4 stroke]

i have parts
doc

 

[wildbonz]

I'll take it into the shop this week and open the chain case. I'll try and take some pictures when I find the problem.
Hopefully it's not too bad.
Any more advice or other places to look would be appreciated.
I'll definately keep that in mind doc.

 

[ITHAPPENS]

Have you checked the chain tension? I have had the chain ride up on the lower sproket, sounds god awful and doesn't move. Fine after tightening, good idea to take it apart to check for damage though...

 

[YammyRX1]

Draining the chaincase oil might tell you something and you can do that without removing anything else. Everything points toward chaincase except the belt riding low, can't explain that unless there are two issues.

 

[jlemieu1]

This sounds a lot of what happened to my 06. My initial thoughs was that I broke my drive shaft because the driver was not turning. Took to the shop and told me that my chain tensor back off some how. Great relief for me because the $600 bill came out to be $70 for chaincase oil change.

 

[monte1214]

Kinda sounds like what I experienced when the chain tensioner post (that the tensioner swivels on) inside my chain chase broke off. God awful sound!! Alot of damage inside...chain case, chain, and both gears were changed under YES warranty.

- x2 on that!

- Sounds like exactly what happened to my 06 RTX last year.

- $700 and I was good to go!

 

[wildbonz]

Well, I took it apart today and this is what I found;

1. When I went to drain the chain case oil, none came out. That wasn't good.

2. The drain plug was still in, but not snugged tight. I had synthetic in there. I am hoping that is where the oil went, and not inside through a bad oil seal. I checked it a few weeks ago and it was good, so I'm hoping it all disappeared on that one ride. I'll do a more thorough check tomorrow.

3. There was still lube on everything, it was pretty much empty, but it wasn't baked dry or anything. I'll take that as a good sign.

4. There was no apparent signs of damage. Nothing was broken or missing or out of place. (Except the oil and the reverse pinion gear has damage, but that I will attribute to earlier problems setting the linkage correctly and having the reverse grinding).

5. The one strange thing was the chain was loose. The tensioner didn't have it snugged up. Thus the grinding sound when it engaged. There was about 3/4 inch left on the tensioner bolt, and I snugged it a few months ago. But when removed the chain was fairly stiff, it didn't just flop around.

6. So what I think happened was, I lost the oil during the day (I have some video of riding that day and all looks and sound good) and while high speed running it home across the lake, 70-90mph for about 10 minutes, it got hot in there, stretched the chain and it started slipping a few times. Once I stopped, the chain was hooped, but the gears survived because it was just a couple seconds.

So I took the parts out and took them to a real mechanic and he figures I should replace the chain, drive sprocket, and reverse pinion gear, along with a bunch of bearings while I'm in there.

I have pictures of the opened case and parts. If anyone wants to see them I can try and post them.

Now I'm going to try to find the parts for a good price with quick shipping. Any suggestions?
70L x 13 Plate chain. 18T drive sprocket. 18T reverse pinion gear. Bearings.

Thanks again, and any more info or help would also be appreciated.

 

[Honk]

So where did 10 oz of oil go?

 

[wildbonz]

I think it's more like 8.5ish I believe.

It doesn't evaporate, so it went somewhere. I'm hoping out the slightly loose drain plug hole.

If not there, it can go through a bad oil seal on the jackshaft bearing and disappear through there.

It could go out the edge if the rubber gasket has a 'wrinkle' in it when it is put back on. Mine has never been off and the rubber seal was on properly.

It could go out the top bearing oil seal to the outside I guess as well, but mine had no sign of oil loss anywhere.

Other than that I don't know. I think it may have gone out the drain hole and been washed away from the snow while riding.

Anyone with more knowledge please correct me so I know where else to look. I'd hate to redo it all then have the same thing happen because I missed something.

Thanks.