Toro 30" mower destroying the mower drive belt

[Baymee]

Toro model 20200, serial number 315000XXX.

Mower ran for years without any mowing issues. Then one day, the belt that connects the motor drive shaft with the smaller pulley of the deck drive, shredded. See pic of that pulley.

Installed a new OEM belt and started the motor. The belt started chirping and then it began to turn the pulley and the unengaged blades started turning. In a minute, the belt burned up.

Installed a second OEM belt. Checked for slack in the cable...yes. checked that the spindle assemblies turned easily.... yes. Checked for deformed pulleys...no. Turned the blades and checked for plenty of slack in the belt....turning the blades does not make the belt turn, plenty of slack.

Started the mower with the blade disengaged and it started chirping again and the blades turned and burned up the belt again.

Installed a different belt, wondering if it's a manufacturer defect in the first two. Again, the belt started chirping and I cut the power to save the belt.

What could be wrong? The only thing that comes to mind is that the pulleys are at fault, but everything looks and feels fine.

 

[bertsmobile1]

Chirping means it is running against some thing that it should not
Usually this is because it is routed on the wrong side of a belt keeper or brake

 

[Forest#2]

It's talking to you and you are not paying attention.
Chirping is the belt friction.

 

[Rivets]

You do know that the blades on your mower are timed and if your blade belt jumped during your repair process, which has happened to many of us, your chirping may be the blades hitting.

 

[Baymee]

I double checked my mower to concur with your suggestions.

The motor sheeve has a guard but it's one that the belt easily slips under and goes around the sleeve.

The idler pulley pushes against the outside of the belt, activated by a cable. The belt itself goes loosely around both sheeves and the idler pulley doesn't touch the belt. The blades are perfectly timed.

When I started the motor, it would run perfectly for about a minute. Then one chirp, then another, and soon the blades would start to turn. So I said, engage the blades asap so that the belt would be working. But even that method after a short time would cause failure. The belt actually started on fire.

Otherwise, the bearings are all good. Everything spins freely.

 

[Hammermechanicman]

"But even that method after a short time would cause failure. The belt actually started on fire.:

You either have a bearing locking up or the belt is rubbing something. "Chirp" tell me a bearing is locking up. Need a pic of a bad belt.

 

[Baymee]

I was disgusted with it so I parked it in the shed for about 2 months. The belts are gone.

The belt in the pics is the final belt that chirped. You can see no wear on the side that touches the idler. The wear from about 45 seconds of running is on both inside edges. The belt is genuine Toro. The only bearing is the arbor and that is brand new.

 

[sgkent]

so the first question is why did you replace the arbor? Was it for the same reason? Or was it something else? If so, what?

 

[Forest#2]

It appears that a v pulley the belt is running in is not rotating freely and the belt starts burning.
Probably a bearing seizure or the bearing is already seized and it's race is spinning in the housing and seizing after it rotates for little while.
Is this the primary belt from the engine to the deck or the secondary deck belt.

Either way it appears you need to remove the deck and inspect closely the pulley bearings. Several involved. Even the secondary belt pulley bearing can cause such but most likely the center driver area. It's not a safe thing to be trying to watch deck rotation as such with the pto in en-gauged even with the blades removed while off the machine or even having someone else watch.
With the deck off you can get a closer look/feel and most likely quickly locate the issue and re-build the deck at same time.

Is this your mower's part list???

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Shop OEM replacement parts by symptoms or model diagrams for your Toro 2-0200 Lawn Tractor (1971)!

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[Baymee]

This is a 30" walk behind. 20200

Initially I thought the arbor was bad because there was slight side to side shaft play. Thinking along the lines of sgkent, I thought it could be bad bearings. Changing the spindle assy didn't do anything.

As I was looking this over tonight, the engine pulley is good, the pulley over that spindle assy is good, the idler slightly touches the belt but it can't move any farther from the belt because the brake is tight against the pulley. If I rotate the blade in the normal rotation, the belt does catch on the pulley and the belt does move. The idler pulley cable does have slack when the brake is on.

There is lots of cable adjustment available if I would use a belt 1/2" longer, but that's not OEM.