By the way, keep in mind the video looks a little strange because the belt is shaking faster than what the video frame rate could capture.

 

Mine do not. I run 2 gravelys. Only time they shook that bad is when I had a blown bearing on one of the spindles.

 

There's something wrong there for sure. Belts not going to last long running like that.

Have this thread moved to Mechanic/Repair and you'll get more eyes on it,

 

By the way, keep in mind the video looks a little strange because the belt is shaking faster than what the video frame rate could capture.

Maybe a tensioner issue it should take up that slack unless belt is stretched or to big

 

They all shake a bit, but that seems excessive to me. Have you checked the belt tensioner spring adjustment?

 

These gravely deck's have a constant belt tension (CBT) system and the springs aren't adjustable.

 

I was able to talk to some people at Gravely tech support today. They said this is a known issue that they're trying to engineer a fix for. They sent some parts to my dealer to install as a test. He should have them Monday and I'll post an update after I see if it works.

 

For anyone interested, I posted a new video that will play in full screen portrait on a phone. It's easier to see what's going on when the video is larger.

 

Tension is wrong for the deck.

 

Either that or the belt is too long. Design flaw. At any rate, I can't see a way to adjust the tension on this particular deck. It appears to be controlled by springs only.

 

I've got 5 Gravelys.
None of them have that much belt slapping.
Hopfully the updated parts will settle thing down.

And BTW, my name is James.

 

I've got 5 Gravelys.
None of them have that much belt slapping.
Hopfully the updated parts will settle thing down.

And BTW, my name is James.

Hey James. Lol. My first name actually isn't James, but my last name is Bond. Get it?

 

don't put your hand on that belt with the engine running ever again dude.

 

?

 

Is it flapping that bad all the time or just on startup and shutdown? You’re video was brief and it was hard to tell.

 

Is it flapping that bad all the time or just on startup and shutdown? You're video was brief and it was hard to tell.

Constantly.

 

Is your motor bolted down tight to the frame?

 

Good thought. I actually hadn't thought of that and I bet my dealer didn't either. I'll check it out tomorrow. It's worth a shot. Thanks.

 

If the belt is to long then the tension would be wrong. If would get the specific of the belt and go to napa and reguest a belt smallerabout 5 mm smaller. see if that will improve tension. Tighten the belt up. The best way to do it if you can get to everything is to remove the belt and with the tensioner fully closed or open switch ever it's routed. Use a string and route how the belt goes. Then measure your string to see how long it is. Afterward release the spring off the tensioner and have it fully open or close which ever way is opposite of what it was in the first measurement then route your string making sure you are up against your tensioner. Measure your string. Substract the first measurement from the second what ever is the answer divide by 2 this where the length of the belt should be. Since we are dealing with too much slack, if the divide by 2 gives you a fraction like 2 and 1/4 then round down. If this give you the belt you already have then you have a weak spring tension the spring for the tensioner needs to be changed with something stronger. Since the tensioner is not adjustable then I would lean toward to long of belt, tensioner is too lose. Also while you have the belt off spin all the spindles and the tensioner and see if you have loose bearings in them this will cause a loose belt also if it's in the spindles you would see it in the cut qualities in there will be streaks in the lawn where one blade is cutting lower than the other one. Lose belt will also cause a cut quality like the blades need to be sharpened. Hope this helps.

 

Everything is brand new from factory, I've never changed the belt. It has whatever length the manual calls for. That doesn't mean it's correct, but if they all came like that, they would've figured out that easy solution by now (you would think).

My dealer checked all the spindles and they were ok but they replaced a couple pulleys they said were wobbling. As you can see, that didn't fix it. The dealer is supposed to try out some parts Gravely sent him next week.

I'm glad I asked about it here because the dealer almost had me convinced it was normal and didn't even need fixing.

 

No way that's normal! Let me know what you find out. If pulleys were wobbled wonder if a spindle shaft is bent. New parts on machines can always be a problem. Most of the times the dealers are more lost than the customers on these situations that's why this forum was formed. Not to be negative or argumentative in any way. You just would not believe the crab I deal with day in and day out from new parts or new machines. I don't trust most dealers . I've been the cause of a few bulletins in the automotive world and every time it starts with an argument with a dealer that has no clue about there own product. Most of these kids are young in these dealerships. Most owners would be scared at the sight of a spark plug and the service managers are usually the best friend to the gm or owner which means they know nothing about problem solution except refer you back to the manufacture. In which case you run in circles until you get tired of it and give up. Check your local law on the "lemon law " follow it and watch and see they will find a cure quick. Lemon law here affects the local dealer as well as manufacturer. That is if it goes this far.i hope I've help in this situation. It's always my intent to help than hurt or argue here

 

No offense taken. I'll let Gravely tinker with it first (they're the one selling mowers they know have a problem, lol), but if that doesn't work I'll dig deep into it myself with the help of you guys' suggestions. I'll post back about what parts they change out or add and whether they made any difference.

 

Here is a long shot.
But.... look it over.
About 5 years ago my worker had a vibration on his deck. Belt had a pretty good flop going on.
I really started looking closely, here it ended up being a Blue Spuce cone wedged deep down into a pulley. Pryed it out. Cured the problem.
It was wedged and flattened so much needed a hammer and screwdriver to get it out.

 

Here is a long shot.
But.... look it over.
About 5 years ago my worker had a vibration on his deck. Belt had a pretty good flop going on.
I really started looking closely, here it ended up being a Blue Spuce cone wedged deep down into a pulley. Pryed it out. Cured the problem.
It was wedged and flattened so much needed a hammer and screwdriver to get it out.

Thanks. Another good suggestion.
The belt has been like that since day one, but that was actually the first thing my dealer checked when I got it off the trailer. He said stuff like that happens a lot. I'll check it over real good myself before I mow today. I'll also check that the engine is bolted down tight.

 

Here's the video I shot after my dealer tested out parts Gravely called an anti-vibration kit. I'm happy to report, the belts run as smooth as I expect them to now.

Sorry for the poor video editing. I don't usually post YouTube videos, but I wanted to share the info with others who may be having the same problem, regardless of how crude my video skills are.

 

It makes me wonder if all pulleys are in correct alignment. The spring loaded tension pulley might be the most suspected one, if in fact there is an alignment problem.

 

Well, the belt shaking was taking place between the engine and the middle deck pulley. As far as alignment goes, those two pulleys are almost never in alignment (on any mower) because of the raising/lowering of the deck. My point being, why would alignment of the rest of the pulleys be so critical? If it was, you'd think they would've figured out a way to move engines up/down with decks to keep everything perfectly aligned.
Does that rationale sound logical at all?