slummagumma
New member
it mows fine but there is a pronounced/loud pulsing, rhythmic sound only when deck belt drive is engaged. Craftsman 42" twin blade deck, 20HP B&S.
I throttle down while belts engaged and the flopping slows as well with RPM changes. I looked under the deck while blades are engaged and the pulley that is linked to the engagement cable (non elect clutch) is bouncing back and forth radically and is likely the part of the noise. Something's just going to wear out prematurely if I don't figure this out. I removed the engagement pulley to install cable spring bolt-eye terminal and it is true with no issues
The long span of belt between the blade spindles in the rear is flopping radically back and forth as well while in drive at full throttle too, and at idle. All this is creating a thump thump sound, but it's cutting grass fine. But it doesn't sound right. There is shiny wear on the little spring which is bouncing back and forth chafing on deck, which returns engagement pulley so I know this is not normal.
The belt is staying on fine, but this unit is new to me and my other mowers don't flop when blades are engaged. They are very smooth.
So....
Pulleys are true, no axle wear, lubricated etc. Spindles are in great condition, bearings not loose or worn, no slop up, down or sideways, pulley brakes pull off well and clear from pulleys. I installed a new engagement cable today. No change, The other broke today.
I just have no idea other than the belt is too loose? Or maybe the wrong belt? It came with the machine which a buddy gave me who went and bought a new ZT mower. So I have no history if belt was mismatched.
Any help on this is greatly appreciated,
Why am I missing?
I throttle down while belts engaged and the flopping slows as well with RPM changes. I looked under the deck while blades are engaged and the pulley that is linked to the engagement cable (non elect clutch) is bouncing back and forth radically and is likely the part of the noise. Something's just going to wear out prematurely if I don't figure this out. I removed the engagement pulley to install cable spring bolt-eye terminal and it is true with no issues
The long span of belt between the blade spindles in the rear is flopping radically back and forth as well while in drive at full throttle too, and at idle. All this is creating a thump thump sound, but it's cutting grass fine. But it doesn't sound right. There is shiny wear on the little spring which is bouncing back and forth chafing on deck, which returns engagement pulley so I know this is not normal.
The belt is staying on fine, but this unit is new to me and my other mowers don't flop when blades are engaged. They are very smooth.
So....
Pulleys are true, no axle wear, lubricated etc. Spindles are in great condition, bearings not loose or worn, no slop up, down or sideways, pulley brakes pull off well and clear from pulleys. I installed a new engagement cable today. No change, The other broke today.
I just have no idea other than the belt is too loose? Or maybe the wrong belt? It came with the machine which a buddy gave me who went and bought a new ZT mower. So I have no history if belt was mismatched.
Any help on this is greatly appreciated,
Why am I missing?
