Toro Timecutter SS5060 Drive Belt/Hydrostatic Drive Belt issue - Solved

[Omega Woods]

About a week ago, DW was mowing while I was moving wood chips with my tractor. We stopped to talk to each other for a minute and when she restarted the mower (Toro Timecutter SS5060, 2014 model) it would not move. It started fine and the mower would engage and disengage but the hydrostat drive wasn't doing its thing.

Anyway, brought it to the house. Sure enough, the drive belt was off. Not damaged, just popped off the pulleys. Odd. Rethreaded the belt and reinstalled the spring. Started the mower. Little POP. Slack spring, belt off again.

Anyway, I reinstalled the belt and had DW tap the starter while watching the belt. The left-hand hydrostat fan which sits just below the drive pulley on either side was pushing the belt up and off the pulley! Two or three of the fins had become deformed (in the upward direction!) somehow. How odd. I thought perhaps something was lodged under one side of the fan and causing it to stick up on one side.

So, today, I dropped the left-side drive assembly and, sure enough, three of the blades were somewhat out of plane with the rest of them. But there was no visible damage to the fan or pulley, nothing lodged under or over the fan. Very unusual. The plastic is not rigid but very tough and semi-pliable. None of the blades showed any cracking or damage except for the extreme tip of one of the blades where it had gotten lodged under the belt (I think).

I got out my head gun and needle-nosed pliers and heated and reshaped the slightly bent blades. I also clipped about an eighth inch off of the end of the one previously mentioned. Reassembled, took it out and mowed an acre. Seems to work fine now.

Sorry I didn't take any pictures, I was working alone without my camera. I just wanted to document this in case someone is troubleshooting a drive belt issue in the future.

 

[rttaylor619]

A few years later, but I have the same thing happening. My Toro MX5060 drive belt is falling / popping off as soon as I turn it on. Tried re-installing the belt multiple times, to no avail. I see the same thing - bent fan blades on the LH Hydro fan pulley assembly blades, and they are hitting (and slightly damaging) the belt and popping it up and off the mower. Glad I'm not the only one this has happened too. Still makes you curious as to what caused the damage to the blades in the first place. Never had an issue with the drive belt in the past!

 

[RalphVa]

About a week ago, DW was mowing while I was moving wood chips with my tractor. We stopped to talk to each other for a minute and when she restarted the mower (Toro Timecutter SS5060, 2014 model) it would not move. It started fine and the mower would engage and disengage but the hydrostat drive wasn't doing its thing.

Anyway, brought it to the house. Sure enough, the drive belt was off. Not damaged, just popped off the pulleys. Odd. Rethreaded the belt and reinstalled the spring. Started the mower. Little POP. Slack spring, belt off again.

Anyway, I reinstalled the belt and had DW tap the starter while watching the belt. The left-hand hydrostat fan which sits just below the drive pulley on either side was pushing the belt up and off the pulley! Two or three of the fins had become deformed (in the upward direction!) somehow. How odd. I thought perhaps something was lodged under one side of the fan and causing it to stick up on one side.

So, today, I dropped the left-side drive assembly and, sure enough, three of the blades were somewhat out of plane with the rest of them. But there was no visible damage to the fan or pulley, nothing lodged under or over the fan. Very unusual. The plastic is not rigid but very tough and semi-pliable. None of the blades showed any cracking or damage except for the extreme tip of one of the blades where it had gotten lodged under the belt (I think).

I got out my head gun and needle-nosed pliers and heated and reshaped the slightly bent blades. I also clipped about an eighth inch off of the end of the one previously mentioned. Reassembled, took it out and mowed an acre. Seems to work fine now.

Sorry I didn't take any pictures, I was working alone without my camera. I just wanted to document this in case someone is troubleshooting a drive belt issue in the future.

The Ryobi ZT (think 480e) has no belts. Nor does the new Ryobi 40v walkbehind. Just has added motors to drive the wheels.

 

[Richard001]

A few years later, but I have the same thing happening. My Toro MX5060 drive belt is falling / popping off as soon as I turn it on. Tried re-installing the belt multiple times, to no avail. I see the same thing - bent fan blades on the LH Hydro fan pulley assembly blades, and they are hitting (and slightly damaging) the belt and popping it up and off the mower. Glad I'm not the only one this has happened too. Still makes you curious as to what caused the damage to the blades in the first place. Never had an issue with the drive belt in the past!

Welcome to TBN

Richard

 

[Omega Woods]

A few years later, but I have the same thing happening. My Toro MX5060 drive belt is falling / popping off as soon as I turn it on. Tried re-installing the belt multiple times, to no avail. I see the same thing - bent fan blades on the LH Hydro fan pulley assembly blades, and they are hitting (and slightly damaging) the belt and popping it up and off the mower. Glad I'm not the only one this has happened too. Still makes you curious as to what caused the damage to the blades in the first place. Never had an issue with the drive belt in the past!

I got to the point that I bought a new ZTR for my farm and took the Toro to my suburban house. So far, it's been on the same belt but it only takes me about 10 minutes to cut the house yard with the Toro. I suspect that the trannies are heating the belt up and with the tight clearances between the pulleys and the bumps at the farm, it's causing belt failure. Anyway, I shouldn't be writing any of this because it will almost certainly happen the next time I'm on the mower since I'm saying it hasn't happened for a while. If it does happen again, it's going on FB marketplace with full disclosure for whatever I can get for it.

 

[ACE123]

About a week ago, DW was mowing while I was moving wood chips with my tractor. We stopped to talk to each other for a minute and when she restarted the mower (Toro Timecutter SS5060, 2014 model) it would not move. It started fine and the mower would engage and disengage but the hydrostat drive wasn't doing its thing.

Anyway, brought it to the house. Sure enough, the drive belt was off. Not damaged, just popped off the pulleys. Odd. Rethreaded the belt and reinstalled the spring. Started the mower. Little POP. Slack spring, belt off again.

Anyway, I reinstalled the belt and had DW tap the starter while watching the belt. The left-hand hydrostat fan which sits just below the drive pulley on either side was pushing the belt up and off the pulley! Two or three of the fins had become deformed (in the upward direction!) somehow. How odd. I thought perhaps something was lodged under one side of the fan and causing it to stick up on one side.

So, today, I dropped the left-side drive assembly and, sure enough, three of the blades were somewhat out of plane with the rest of them. But there was no visible damage to the fan or pulley, nothing lodged under or over the fan. Very unusual. The plastic is not rigid but very tough and semi-pliable. None of the blades showed any cracking or damage except for the extreme tip of one of the blades where it had gotten lodged under the belt (I think).

I got out my head gun and needle-nosed pliers and heated and reshaped the slightly bent blades. I also clipped about an eighth inch off of the end of the one previously mentioned. Reassembled, took it out and mowed an acre. Seems to work fine now.

Sorry I didn't take any pictures, I was working alone without my camera. I just wanted to document this in case someone is troubleshooting a drive belt issue in the future.

Eureka!!! I'm been having the same problem. I put a smaller belt on it and that worked for awhile but it was a son of a ***** to get it on so I went with the oem one and it would pop it off right at start up! It was driving me crazy!!! I looked at all the pulleys nothing bent but I noticed the fan blades had some discoloration. I was getting ready to put a mechanical tensioner on the spring to give it more force but that can wait now!!! I'm going to take a heat gun and bend them back up and mow some grass! No more Toro's for me!!! I've only got 40 hrs on the machine I had to put a mechanical tensioner on the mower deck so I don't have to buy those $60 dollar belts every two months!

 

[Omega Woods]

Good luck. I’ve basically scrapped mine because of this issue. Incredibly aggravating. I’ll never buy another consumer grade mower.

I’m convinced the bent fan blades are a symptom and not a cause. The left drive seems to be overheating and trashing the belt and fan. Replacement costs more than the value of the mower and I don’t have the time or patience to change drive belts two or three times per season.

I bought a replacement mower and moved on a couple of years ago.