Belt Tension on a Rear PTO Belly Mower

[srjones]

I recently got a 48" Contintental belly bower and today I installed it and took for a test drive. Overall, I really like it, but I'm wondering what the right tension for the belt should be. I think may be too loose since it seems shake a lot under no load and seems to slip at other times when I hit taller grass (without bogging down the tractor too much).

Without getting a manual, does anyone have an suggestions on the tension for a belt like this? Should it be like the tension on an engine belt or would that be too tight?

I can post pics if needed.

Thanks,

-Steve

 

[greg_g]

A loose drive belt shouldn't make the deck vibrate, that sounds like some other kind of problem. Or are you talking about the belt itself "shaking" ?

If the belt shows a tendency to move in and out on itself at various RPMs, it's too loose. Unfortunately, long belts like that can't be tensioned in the same manner as you would under the hood of an older car or truck. In this case, you tighten the drive belt in small increments, to the point where you no longer observe this in/out movement as the deck spins up and down.

//greg//

 

[srjones]

Thanks Greg,

It's just the belt shaking, not the deck itself. It reminds me of the belt on my tablesaw when it's too loose.

I'll try tightening it in small increments. I've also read that they should be loosened during storage, so maybe that's what happened?

-Steve

 

[greg_g]

I've also read that they should be loosened during storage, so maybe that's what happened?

-Steve

Well, that's for any rubber belt - not just on that particular machine. Since this is the first time you've mounted it on your tractor, I think it's just a matter of getting everything on the mower adjusted to it's new ride.

//greg//

 

[zzvyb6]

Remove the belt and check to see if its been rubbing against anything within the belt raceway. I mean the outside of the belt. Yes there may be contact with the tensioner but not enough to scrub the backside. Check the length against the manual to see if its the right belt size and width. There are several 'strengths' to belt materials, std, Green, etc. You do have the ability to change the tension but too much will prevent slippage if you hit an unmovable object like rock, fence post end, log, steel post, etc. That could cost you a gearbox or driveshaft. If it's whipping too much for you, try tightening the tensioner down so it has more friction. (not spring rate, but damping). Lastly, you might find that it actually has too much tension, so loosening the belt tension will reduce the whipping because: since the damping is fixed, lowering the spring rate will increase the effective relative damping.

 

[greg_g]

there may be contact with the tensioner but not enough to scrub the backside. ... You do have the ability to change the tension ... try tightening the tensioner down so it has more friction. (not spring rate, but damping). .. you might find that it actually has too much tension ...lowering the spring rate will increase the effective relative damping.

I don't think you understand we're talking about a rear PTO driven belly mower drive belt. There's no spring tensioner that I've ever seen. The five footer I had went like this: PTO spline > PTO shaft (w/shear bolt) > mower transmission > very large horizontal output pulley > very very long V-belt > normal mower drive pulley. Dat's all. Drive belt tension on mine was adjusted by moving the deck forward/aft on the support column.

//greg//

 

[srjones]

...PTO spline > PTO shaft (w/shear bolt) > mower transmission > very large horizontal output pulley > very very long V-belt > normal mower drive pulley. Dat's all. Drive belt tension on mine was adjusted by moving the deck forward/aft on the support column.

//greg//

Yep, that's pretty much it. Tension is adjusted by turning two nuts on a bolt that shortens/lengthens it along the support column. I got it stuck in the mud mowing tonight, but when I get it pulled out tomorrow morning, I'll take some good pics to illustrate.

 

[BTDT]

I got it stuck in the mud mowing tonight

Been a long winter, huh? Trying to catch up.

 

[greg_g]

I got it stuck in the mud mowing tonight, but when I get it pulled out tomorrow morning, I'll take some good pics to illustrate.

I mowed a lot of rolling ground where run-off areas can be wet for days after a rain. Because of balloon-type turf tires and two wheel drive, I know the aggravation of getting stuck while mowing. If it helps, I found that removing the deck gauge wheels temporarily - and engaging the rear diff lock - sometimes let me drive out of the situation. Even if not, removing the gauge wheels usually made getting pulled out less messy.

//greg//

 

[srjones]

I got it stuck in the mud mowing tonight

Been a long winter, huh? Trying to catch up.

Have you ever been to western Oregon in the spring?