X300 snowthrower throws belt

bu11seye · Jan 18, 2020

My X300 with a 44 inch snowthrower keeps throwing the belt in heavy wet snow. It's on its fourth season and the units stay together all year long because I use another machine for grass and leaves. The belt jumps off the left sheave and out of the guide. The guide bent away from the rim of the sheave. After refastening the belt I bent the guide back into a vertical position. The machine behaved itself until I was pushing/throwing a large heavy pile to the driveway edge, then it threw the belt again. What am I missing? How close should the guide be to the sheave? It is getting harder for my 72 year old carcass to work on things but I won't stop until they pry my wrench from my cold dead fingers.

~Lee

Diggin It · Jan 18, 2020

I had one of the two mowers shown below (can't remember which now) throw or eat mower deck belts a couple of times a year, sometimes after only a few hours. I'm not sure I ever did figure out exactly why, but after I went through all the bearings and pulleys including the idlers and rechecked the deck mounting and alignment, it seems to have stopped.

Double and triple check all of the blower alignment points visually looking to see if the belt itself seems straight. Make sure nothing moves under stress. Get a helper if possible to push and pull here and there. Check and lube all bearings and bushings in everything, even if they're supposed to be 'permanently lubed'. Run each by hand (belt off so they rotate easily) and 'feel' for any roughness while listening for any rumbling or squealing. Shoot them all with some type of penetrating lubricant along the lines of WD40, but heavier.

Any single pulley doesn't need to tweak very far out of alignment for a belt to jump off under power.

beenthere · Jan 18, 2020

Photo or two would help with a possible answer.

Sounds like a possible bearing going bad.. but that is just a guess. Alignment of pulley's maybe part of the problem too.

In the meantime, don't be aggressive with the heavy piles...

Hope you find the problem.. How old is the John Deere drive belt, and is it without nicks and cracks?

seville009 · Jan 18, 2020

Not sure if it applies to your situation, but the deck belt in my zero turn mower kept popping off last summer when I hit stuff with the deck. Nothing looked wrong, but put a new belt on and problem was solved. I think the old belt was just stretched just a little bit - couldn’t tell by just looking at it; was in good shape with no cracks or missing pieces.

So..... I’d stick a new belt on. Worst case is that you end up with a spare belt.

radios1 · Jan 18, 2020

I found this. "The document I got from my JD dealer last year was titled "//dtac.deere.com/Solutions/English/75064.htm" published Feb. 20, 2014. It is labeled "Solution Number 75064". Solution Summary States: "Belt Jumps Off On 44-in or 47-in Snow Blowers- X3/X5 Select Series".

The solution says order "1 M154563" Belt Guide, "1 M78494" spacer, and "1 03M7095" Cap Screw. Install per 75064 1.jpg photo. Basiclly the photo shows adding a 2nd spacer on the left hand sheave pulley. The cap screw just replaces the original sheave pulley cap screw as it is about a 1/2 inch longer. I think my dealer gave the extra spacer and cap screw last year. If your dealer can't print a copy of this "DTAC", let me know and I can scan or mail you a copy of mine.

The belt guide listed above may all ready be on your blower if it was built in the last couple of years. Mine had it. It is the guide that is attached to left hand side of blower to keep the belt on the large gear box pulley.

I ran my blower about 3 hours this morning trying to move a 3 ft. drift on my hobby farm. I checked the belt several times and didn't notice any belt shredding like last year. And this belt was one that I turned around after I did the suggested fix on the idler pulley. I think this is the longest time I have seen a belt go without starting to shred.

It also states at the bottom of this solution, "If the this recommendation does not resolve the issue, then replace both sheave pulleys with AM132764 pulleys". I think these might be larger pulleys as my dealer had one of these on hand as they are for another application. Also in the solution it states to change the plate alignment to be lower in the back so the sheave pulleys best align with the engine pulley when the blower is in its down position. In this solution it does not indicate that there is a replacement plate available. But since this is a year old document, JD could have made one available."

bu11seye · Jan 19, 2020

Diggin It said:
I had one of the two mowers shown below (can't remember which now) throw or eat mower deck belts a couple of times a year, sometimes after only a few hours. I'm not sure I ever did figure out exactly why, but after I went through all the bearings and pulleys including the idlers and rechecked the deck mounting and alignment, it seems to have stopped.

Double and triple check all of the blower alignment points visually looking to see if the belt itself seems straight. Make sure nothing moves under stress. Get a helper if possible to push and pull here and there. Check and lube all bearings and bushings in everything, even if they're supposed to be 'permanently lubed'. Run each by hand (belt off so they rotate easily) and 'feel' for any roughness while listening for any rumbling or squealing. Shoot them all with some type of penetrating lubricant along the lines of WD40, but heavier.

Any single pulley doesn't need to tweak very far out of alignment for a belt to jump off under power.

I got a new belt yesterday and ordered a new guide.

~Lee

bu11seye · Jan 19, 2020

Thanks, I bought a new one yesterday and ordered a new guide.

~Lee

bu11seye · Jan 19, 2020

radios1 said:
I found this. "The document I got from my JD dealer last year was titled "//dtac.deere.com/Solutions/English/75064.htm" published Feb. 20, 2014. It is labeled "Solution Number 75064". Solution Summary States: "Belt Jumps Off On 44-in or 47-in Snow Blowers- X3/X5 Select Series".

The solution says order "1 M154563" Belt Guide, "1 M78494" spacer, and "1 03M7095" Cap Screw. Install per 75064 1.jpg photo. Basiclly the photo shows adding a 2nd spacer on the left hand sheave pulley. The cap screw just replaces the original sheave pulley cap screw as it is about a 1/2 inch longer. I think my dealer gave the extra spacer and cap screw last year. If your dealer can't print a copy of this "DTAC", let me know and I can scan or mail you a copy of mine.

The belt guide listed above may all ready be on your blower if it was built in the last couple of years. Mine had it. It is the guide that is attached to left hand side of blower to keep the belt on the large gear box pulley.

I ran my blower about 3 hours this morning trying to move a 3 ft. drift on my hobby farm. I checked the belt several times and didn't notice any belt shredding like last year. And this belt was one that I turned around after I did the suggested fix on the idler pulley. I think this is the longest time I have seen a belt go without starting to shred.

It also states at the bottom of this solution, "If the this recommendation does not resolve the issue, then replace both sheave pulleys with AM132764 pulleys". I think these might be larger pulleys as my dealer had one of these on hand as they are for another application. Also in the solution it states to change the plate alignment to be lower in the back so the sheave pulleys best align with the engine pulley when the blower is in its down position. In this solution it does not indicate that there is a replacement plate available. But since this is a year old document, JD could have made one available."

Thanks for all the extra details! I visited PARTS yesterday, got a new belt and ordered a new guide. I'm also going to be less aggressive with the icy piles that lift the blower.

~Lee

Richard001 · Jan 19, 2020

How to: Replace John Deere 44 inch snow thrower belt on 300 series tractor
How to: Replace John Deere 44 inch snow thrower belt on 3 series tractor - YouTube

If this is the same snow thrower you have, replacing the belt is really difficult. JD did a horrible job on putting that thrower together. Those belt guides on the pulleys should be welded in place and the bolt that holds the pulley should be a stud, not a loose bolt,

And as you can see in the video, he can not get the one guide back in place with the belt on the pulley.

Also I have to assume that one of the pulleys is spring loaded. That's a long belt from the engine to the thrower. Engine power pulses will cause the belt to flop around. The spring loaded pulley can not stop it. As a matter of fact, at certain engine RPM, there will be a resonance with the pulley and belt that will greatly increase the belt flop.
.
The belt flopping around is most likely what is causing your belt to come off the pulley. From watching the video, it appears that there is no belt guide on the main engine pulley. When the belt is flopping around, it will get very loose as the spring load idler is bouncing back and forth. This will cause the belt to come off of the engine pulley or the spring laded idler.

The simplest cure for this is a rubber stop positioned just behind the spring loaded idler. It has to be positioned so that the idler can not bounce away from the belt. In the past, on my own snow thrower with a long belt, I used an old shock absorber top mount. In addition to that, I also used a belt flopping pulley about half way between the two pulleys. It had just enough tension on the belt to be in contact with it at all times. I put it on the slack side of the belt between the two pulleys.

Richard

bu11seye · Jan 20, 2020

Richard001 said:
How to: Replace John Deere 44 inch snow thrower belt on 300 series tractor
How to: Replace John Deere 44 inch snow thrower belt on 3 series tractor - YouTube

If this is the same snow thrower you have, replacing the belt is really difficult. JD did a horrible job on putting that thrower together. Those belt guides on the pulleys should be welded in place and the bolt that holds the pulley should be a stud, not a loose bolt,

And as you can see in the video, he can not get the one guide back in place with the belt on the pulley.

Also I have to assume that one of the pulleys is spring loaded. That's a long belt from the engine to the thrower. Engine power pulses will cause the belt to flop around. The spring loaded pulley can not stop it. As a matter of fact, at certain engine RPM, there will be a resonance with the pulley and belt that will greatly increase the belt flop.
.
The belt flopping around is most likely what is causing your belt to come off the pulley. From watching the video, it appears that there is no belt guide on the main engine pulley. When the belt is flopping around, it will get very loose as the spring load idler is bouncing back and forth. This will cause the belt to come off of the engine pulley or the spring laded idler.

The simplest cure for this is a rubber stop positioned just behind the spring loaded idler. It has to be positioned so that the idler can not bounce away from the belt. In the past, on my own snow thrower with a long belt, I used an old shock absorber top mount. In addition to that, I also used a belt flopping pulley about half way between the two pulleys. It had just enough tension on the belt to be in contact with it at all times. I put it on the slack side of the belt between the two pulleys.

Richard

Thanks Richard for the hints. We woke up to four-five inches of the white stuff and it is still coming down. We'll give it a go after our morning coffee.

~Lee