Mid-Mount Drive Belt Is Flopping Around (Video)

[Tinhack]

Those belts look worn out.

It looks like someone has modified the spring tension hook on the deck at some point. That may also be a contributing factor.

The original probably broke off. May be a new spring too. Most spring tensioners have an adjustment as well.
Check a parts book for the spring setup and get the correct belts.

 

[pmsmechanic]

To me it looks like the pulley by itself in the center is the belt tensioning pulley. There is an arm under it connected to the spring. The pivot point of the arm is the bolt below the pulley in the picture. Make sure that arm moves freely through it's complete range of movement. A few more ideas: A larger idler pulley would compensate for the longer belt. Maybe all you need is a heavier spring

 

[mkadyz]

Thanks to everyone who replied with suggestions . I’m going to rebuild the spindles this winter so I’ll take care of the belt issue while I’m at it.

 

[ROUSTABOUT]

I would put bearing idler pulleys on the back side of the belt. Kubotas just have them two pegs sticking up. I've replaced many belts worn because those two pegs wore the belt from the back side. This is from working at Kubota. Keep oil in the gearbox too, be very attentive to that.

 

[dodge man]

What rpm is that at? I had a BX2350 that if you didn’t crank up the rpm’s to near full throttle the belt would do that.

 

[mkadyz]

I would put bearing idler pulleys on the back side of the belt. Kubotas just have them two pegs sticking up. I've replaced many belts worn because those two pegs wore the belt from the back side. This is from working at Kubota. Keep oil in the gearbox too, be very attentive to that.

This was actually my reason for the post. I wasn't sure if this was a design issue that needed to be corrected or if I just had the wrong belt / spring setup.

What rpm is that at? I had a BX2350 that if you didn’t crank up the rpm’s to near full throttle the belt would do that.

Is was only at about 1000 RPM when I recorded it. I'll check it again at pto rpm and see if it tightens up.

 

[mkadyz]

I should also add, that I realize in the video the belt looks super floppy, but when it is stationary on the mower it is nice and tight like you would expect it to be. Maybe not tight enough, but it definitely isn't loose.

 

[ROUSTABOUT]

I should also add, that I realize in the video the belt looks super floppy, but when it is stationary on the mower it is nice and tight like you would expect it to be. Maybe not tight enough, but it definitely isn't loose.

Idler tension pulley, does it have the right spring?

 

[pmsmechanic]

I should also add, that I realize in the video the belt looks super floppy, but when it is stationary on the mower it is nice and tight like you would expect it to be. Maybe not tight enough, but it definitely isn't loose.

Check to see if all 4 of your pulleys are running true. If one is offset a bit it could make the belt flop around.

 

[CH4Ohio]

It just doesn't look to me like there's any spring tension on the idler pulley. Did the idler pulley spring have to be stretched an inch or more in order to get the belt on? It needs to be under tension and I'd expect to see it moving back and forth somewhat with that much belt movement.