That looks like the drive belt idler tension pulley spring.
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X300 breaking belts
- Thread starter JHouston57
- Start date
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Export threadThat looks like the drive belt idler tension pulley spring.
I had the same problem with my x304. I re-leveled the deck and that took care of the problem. It was slightly off front to back just enough to cause the problem. There is very little clearance on the height adjustment arm on the right side so leveling is critical. Also, as a precautionary measure, I set the deck height to max when starting the blades initially then set it down to desired height. Haven't broken a belt in7-8 years now. Hope this helps.Greetings all,
I bought a new X300 from a local JD dealership just before the 2015 mowing season. I mow appx 1.5 acres weekly with an additional .75 acres about every two to three weeks during the season.
Love the mower, I have it serviced "front to back" at the end of each season and it worked perfectly during the 2015, 2016, 2017 and 2018 seasons. At the beginning of the 2019 season, the large deck or blade belt broke after about two weeks of mowing. The belt was replaced and I was able to mow about four weeks when the second belt broke. I have now mowed about 8 - 10 weeks and the third belt broke today!
Has anyone else had this problem? Any suggestions? I just can't understand how the mower has worked perfectly for 4 seasons and now I have experienced 3 broken belts in one season..
Any help or suggestions are appreciated.
JHouston
I joined specifically to post this report because Will1988's message above helped me FINALLY solve my x300 belt breakage problem. I wanted to give back to the forum and help others having the same issue. Searches revealed lots of people having this issue but almost nobody mentioning the PTO clutch wear characteristic.
My x300 is a 2008 with the 42 inch Edge deck and it has just over 300 hours on it. I've owned it since new and store it in a clean barn. I have 3 acres, mow half of it as lawn, and the other half less often as pasture, sometimes letting it get 6 to 8 inches long before mowing. I bag the lawn areas once in the spring to get rid of heavy clippings, and once or twice in the fall to clear leaves. Most of the time I'm throwing. My first belt lasted over ten years. The second belt lasted several more, then two years ago i went through 2 belts in a season, and last year and this year I've been lucky to get three mowings out of a belt.
I've used OEM John Deere M154621 belts only. While the bolt clearance issue is close on mine, there is no evidence of any rubbing. The pulley alignment seems ok, and I've replaced spindles and one of the pulleys that had a bearing that was getting iffy. My belts were clearly failing in overload rather than due to obvious excessive rubbing, although the belt and pulleys get moderately hot. I couldn't figure it out until I read the post above mentioning the PTO getting grabby as it wears. It made me realize that blade engagement was slowing the motor down noticeably and the engagement definitely was more grabby that it used to be causing some shaking of the tractor.
I removed the PTO clutch (piece of cake - thanks Deere assemblers for using anti-sieze on the motor shaft) and took it apart using youtube videos for guidance. The clutch surfaces were definitely worn, but more importantly had scratchy looking fretting damage all over the contact surface. I ordered a new John Deere PTO clutch AM141536 ($200) and installed it. There was an obvious change to the feel and sound of the engagement. First, the engagement makes a Sssshhh sound for 1/2 second or so ("Oh yeah, I remember that sound now from years ago!"), the engine speed hardly drops at all, and NO tractor vibration with blade startup. So far so good. I will post again at the end of the mowing season to confirm the belt has not broken. .
So if you have the belt breakage issue, you've checked everything else, and your belts appear to be failing due to overload (a fairly clean break that almost always occurs when engaging the mower, with no evidence of rubbing), you don't hear an obvious Ssssshhhh (slipping) sound on PTO engagement, and you get a speed dip and tractor vibration on PTO engagement, I would highly suspect your PTO clutch is worn to the point where it is grabbing too hard and overloading the belt.
Thanks again Will1988.
Update October 17, 2020: Still on the same belt I installed when I replaced the electric mower clutch in June. I have mowed the 3 acres at least 8 times (stopping and starting the mower a few times with each mowing as needed), including two mowings while bagging which involves dozens of mower start-stop cycles due to emptying the bags. Replacing the PTO clutch definitely fixed the issue.
My x300 is a 2008 with the 42 inch Edge deck and it has just over 300 hours on it. I've owned it since new and store it in a clean barn. I have 3 acres, mow half of it as lawn, and the other half less often as pasture, sometimes letting it get 6 to 8 inches long before mowing. I bag the lawn areas once in the spring to get rid of heavy clippings, and once or twice in the fall to clear leaves. Most of the time I'm throwing. My first belt lasted over ten years. The second belt lasted several more, then two years ago i went through 2 belts in a season, and last year and this year I've been lucky to get three mowings out of a belt.
I've used OEM John Deere M154621 belts only. While the bolt clearance issue is close on mine, there is no evidence of any rubbing. The pulley alignment seems ok, and I've replaced spindles and one of the pulleys that had a bearing that was getting iffy. My belts were clearly failing in overload rather than due to obvious excessive rubbing, although the belt and pulleys get moderately hot. I couldn't figure it out until I read the post above mentioning the PTO getting grabby as it wears. It made me realize that blade engagement was slowing the motor down noticeably and the engagement definitely was more grabby that it used to be causing some shaking of the tractor.
I removed the PTO clutch (piece of cake - thanks Deere assemblers for using anti-sieze on the motor shaft) and took it apart using youtube videos for guidance. The clutch surfaces were definitely worn, but more importantly had scratchy looking fretting damage all over the contact surface. I ordered a new John Deere PTO clutch AM141536 ($200) and installed it. There was an obvious change to the feel and sound of the engagement. First, the engagement makes a Sssshhh sound for 1/2 second or so ("Oh yeah, I remember that sound now from years ago!"), the engine speed hardly drops at all, and NO tractor vibration with blade startup. So far so good. I will post again at the end of the mowing season to confirm the belt has not broken. .
So if you have the belt breakage issue, you've checked everything else, and your belts appear to be failing due to overload (a fairly clean break that almost always occurs when engaging the mower, with no evidence of rubbing), you don't hear an obvious Ssssshhhh (slipping) sound on PTO engagement, and you get a speed dip and tractor vibration on PTO engagement, I would highly suspect your PTO clutch is worn to the point where it is grabbing too hard and overloading the belt.
Thanks again Will1988.
Update October 17, 2020: Still on the same belt I installed when I replaced the electric mower clutch in June. I have mowed the 3 acres at least 8 times (stopping and starting the mower a few times with each mowing as needed), including two mowings while bagging which involves dozens of mower start-stop cycles due to emptying the bags. Replacing the PTO clutch definitely fixed the issue.
Last edited:
Hi Jon R. Thanks. I had the exact same mower, model year and problems as you. Belts are snapping. They don't seem to be rubbing. I replaced several of the pullies as well. I replaced the PTO last year (very easy) and things improved slightly, but I'm still breaking a ton of belts. I think I have an additional pully alignment issue. I'm at my wits end with this thing. I just watched this videoI joined specifically to post this report because Will1988's message above helped me FINALLY solve my x300 belt breakage problem. I wanted to give back to the forum and help others having the same issue. Searches revealed lots of people having this issue but almost nobody mentioning the PTO clutch wear characteristic.
My x300 is a 2008 with the 42 inch Edge deck and it has just over 300 hours on it. I've owned it since new and store it in a clean barn. I have 3 acres, mow half of it as lawn, and the other half less often as pasture, sometimes letting it get 6 to 8 inches long before mowing. I bag the lawn areas once in the spring to get rid of heavy clippings, and once or twice in the fall to clear leaves. Most of the time I'm throwing. My first belt lasted over ten years. The second belt lasted several more, then two years ago i went through 2 belts in a season, and last year and this year I've been lucky to get three mowings out of a belt.
I've used OEM John Deere M154621 belts only. While the bolt clearance issue is close on mine, there is no evidence of any rubbing. The pulley alignment seems ok, and I've replaced spindles and one of the pulleys that had a bearing that was getting iffy. My belts were clearly failing in overload rather than due to obvious excessive rubbing, although the belt and pulleys get moderately hot. I couldn't figure it out until I read the post above mentioning the PTO getting grabby as it wears. It made me realize that blade engagement was slowing the motor down noticeably and the engagement definitely was more grabby that it used to be causing some shaking of the tractor.
I removed the PTO clutch (piece of cake - thanks Deere assemblers for using anti-sieze on the motor shaft) and took it apart using youtube videos for guidance. The clutch surfaces were definitely worn, but more importantly had scratchy looking fretting damage all over the contact surface. I ordered a new John Deere PTO clutch AM141536 ($200) and installed it. There was an obvious change to the feel and sound of the engagement. First, the engagement makes a Sssshhh sound for 1/2 second or so ("Oh yeah, I remember that sound now from years ago!"), the engine speed hardly drops at all, and NO tractor vibration with blade startup. So far so good. I will post again at the end of the mowing season to confirm the belt has not broken. .
So if you have the belt breakage issue, you've checked everything else, and your belts appear to be failing due to overload (a fairly clean break that almost always occurs when engaging the mower, with no evidence of rubbing), you don't hear an obvious Ssssshhhh (slipping) sound on PTO engagement, and you get a speed dip and tractor vibration on PTO engagement, I would highly suspect your PTO clutch is worn to the point where it is grabbing too hard and overloading the belt.
Thanks again Will1988.
Update October 17, 2020: Still on the same belt I installed when I replaced the electric mower clutch in June. I have mowed the 3 acres at least 8 times (stopping and starting the mower a few times with each mowing as needed), including two mowings while bagging which involves dozens of mower start-stop cycles due to emptying the bags. Replacing the PTO clutch definitely fixed the issue.
bertsmobile1
Lawn Royalty
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- Nov 29, 2014
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FWIW
Had a customer which the same problem
We cut the bolt short as per a JD service notice but it kept on eating belts by a strait snap
This is indicative of an overload and as I see it the tensioning arm spring is not doing it's job adsorbing shock loads .
I could not see any way to modify the tension arm so we tried a 5/8 belt from a ZTR
Problem solved
The belt does not sit well in the pulleys as it is too wide so runs right at the edge of the pulleys but to date he has run this belt for 4 years which is the longest he has ever had a belt run on this deck .
Had a customer which the same problem
We cut the bolt short as per a JD service notice but it kept on eating belts by a strait snap
This is indicative of an overload and as I see it the tensioning arm spring is not doing it's job adsorbing shock loads .
I could not see any way to modify the tension arm so we tried a 5/8 belt from a ZTR
Problem solved
The belt does not sit well in the pulleys as it is too wide so runs right at the edge of the pulleys but to date he has run this belt for 4 years which is the longest he has ever had a belt run on this deck .
Thanks. I'll have to see if I can find that 5/8 belt.FWIW
Had a customer which the same problem
We cut the bolt short as per a JD service notice but it kept on eating belts by a strait snap
This is indicative of an overload and as I see it the tensioning arm spring is not doing it's job adsorbing shock loads .
I could not see any way to modify the tension arm so we tried a 5/8 belt from a ZTR
Problem solved
The belt does not sit well in the pulleys as it is too wide so runs right at the edge of the pulleys but to date he has run this belt for 4 years which is the longest he has ever had a belt run on this deck .