Could you stick a piece of pipe over that bolt, and bend it out a bit, so it doesn't rub on the belt? I'm not familiar with that model, but when i have a problem like that, the pipe will tend to alleviate the problem somewhat.
Doing this will bend the area where the bolt goes thru the floor pan, maybe just enough for the belt to not rub.

I have an X300 and I looked under at each bolt and at multiple deck height levels with no obstructions. The closest bolt is a 1/2" away. Can you give a better description looking from the front to back on witch bolt it is so I can reference mine.

Have you taken it to your dealer? It is under warranty you know. There are a lot of X300 owners on this board, and I don't think I've heard that before. Given that, I'm sure something is amiss and the dealer could remedy it.

I agree with engine tech I have never heard of this that's why I'm so curious. It is under warranty for sure time wise but depending what the problem ie bent brackets etc.. I don't know if the dealer would give you a hard time. Some dealers are great some others are just jerks. Is it possible the belt is not routed correctly?

I have the 07 model X300 and have not had this problem.I am into my second season of cutting. Would definitely consult dealer. Good luck.

I have the same model and had the same problem. I brought it back to the dealer. They said they called Deere and they said to "bend the belt tensioner arm". This was not an acceptable solution to me. The dealer got mad and didn't want to swap for another mower which is in the JD 30 day guarantee. I called Deere, they called the dealer and he refunded me the purchase price. I went to another dealer and purchased the same mower. I haven't had any problems with it. I called JD and discussed it with them, and they claimed they never heard of that problem. When I went to get my refund at the dealer, they said they discussed it with JD and many of the mowers had this problem. I talked with two people at JD and neither one knew what a X300 was. I finally talked to a supervisor who knew what a X300 was, but had never heard of that issue with them.

Mark,
What is the 2 dealers names?
Thanks

Stupidjohn, that is why you buy John Deere (aside from the pretty green and yellow paint), for the dealer support. Let us know what they find so people with this problem in the future know how to best deal with it. If people with X300's were shedding belts like this I am sure there would be multiple posts here on it, I think your mower has issues (probably due to improper assembly IMHO). Good Luck.

I origionally bought the X300 from Quality Equipment. I gave it back to them and re-purchased one from Welsh Equipment. Quality Equip told me they talked to JD tech support and to bend the tension arm. They actually did this. I would not accept that as a fix for a brand new mower. I told them to call Deere again and let me hear it from an engineer. Wouldn't do it. I asked Welsh if they ever heard of the problem and they said no. I called Deere and they said they had never heard of it. There is about a 3/8 clearance on this one. On all the ones at Welsh there was only about 3/8 in clearance,but since it is electric pto the distance remains constant. But it is still poor engineering in my opinion. No other problems, its a really good machine. I would go to the dealer and show them, and request to see a John Deere factory rep. I really looked at the first one really hard and couldn't see anything making it rub. The belt routing, leveling arms everything seemed to be normal.

It's not unusual for drive belts to run close to other components - you should see what it's like under a Toro Z597D! What's important is how much the belt flaps about, allowing it to TOUCH other components. Some belts just do that, even when properly tensioned! There may be some other reason why the belt touches the leveling adjuster on this machine, and that's what I'd be looking at.

Stupidjohndeere, I also purchased a JD X300 and you are definitely not along with your belt shredding problem I have 11 hours on my tractor and I'm on my 3rd belt. The first one shredded after 8 hours, the second one started to show signs of shredding after only 3 hours. The dealer I purchased from has been trying to find a fix for it. The mechanic has been in contact with JD's engineering department and they been applying new guides along the belt path in an effort to stop the belt from rubbing and shearing. To say I'm frustrated is an understatement. 2 things I can say, the tractor itself is a great machine and thank goodness JD backs their products with a 4 year warrenty. BTW, the mechanic has told me that when Deere figures out why their belts are coming apart they will put out a service bulliten, under then it's kind of trial and error. If this happens again I'm going to try and get in contact with the JD Rep and see what else can be done. Nothing shreds belts like a Deere

Yeah I have the same belt shredding problem with my new X300 as well. I have only 9 hours on my mower and while I was changing the oil I took a good look at the deck and my belt is excessively worn and doesn't look like it will last much longer. The owner's manual says to check the belt at 100 hours, so obviously something is wrong. All the sheaves seem to be aligned OK, although there is one sheave that looks like it could be a little low...but I can't figure out how to change the height, I loosened the bolt on top of the sheave but there is no way I can see to adjust the height of the sheave. I will definitely be calling my JD dealer next week to discuss this problem and I''ll let him know I'm not the only one having this problem. I'm also going to take a look at the leveling adjustment bolt and see if that is the problem as you guys have discussed.

I have 15 hrs on my x300 and no issues with the belt. I would definately have a JD dealer look at it.

Well, I sent an email to my JD Dealer service department and attached a close-up picture of the mower deck that showed the shredded belt (top cover worn off down to rubber core of belt). I got a phone call back from the service rep this morning and he told me there is a modification kit they have to install to fix this problem that the X300's are having. They sent a truck w/trailer out to my house this morning and brought the mower back to their shop. They said they'll get it fixed and get it right back to me.

So, it sounds like JD has figured out what the problem is and have designed a modification kit for all X300s that are having this problem.

We'll see...I am happy with the dealer service so far though, it was basically 24 hours from the time I sent the email to the time they were at my house to get the tractor and start working on it.

Will let you know how things go from here.

This seems to be an old thread but I shredded the deck belt on my x300 at 51 hours. mybeltshredstoo mentioned a modification kit from John Deere but no followups. Does anyone know about this kit? part number or other identifying code that i can correct the interference between the belt and the deck adjustment bolt?

Thanks for your time and help.

Hmm very familiar with this problem... it turns out I was being sold the wrong sized belt. Haven't had one break since the right size was installed. I think the JD parts list may need to be looked at..Cheers

wouldyou be able to give me the part# for this belt I have replaced belt 6 times since first of march replaced all pulleys and tension assembly about to pull what little hair I have out thanks Sam M

Had this problem since the day I bought it. Have replaced belt at least 1 time each year, and more most years.

I have a 2010 X300 with 310 hours on it. Still running the original deck (42) belt and drive belt. Only problem I have is if the mower is raised to the transport or highest position and deck engaged the belt pops off, I just don't raise it.

My X300 past 400 hours before a belt change. I only take it to the "authorized dealer" for service.

We’re on our 4th belt in two years On the x300. The dealer acts like it’s our fluke. No hel at all. We had a carburetor problem that they “fixed” 3 times and still didn’t work. I finally emailed JD headquarters and “suddenly an inexpensive plastic part was the solution. No refund on cost of previous work. I like JD mower except for bad stuff and no knowledge or help from dealer for repairs. They had our mower for 3 weeks during grass growing season. Not planning on another JD purchase.

What was that part? I added 3 belt guides to a 42 inch X300 only to discover the blades added by the first seller were not Deere uplift blades! Concurrently on same belt since Jan.

Adding my $0.02 here as well. Have the exact same issue with my X300 and 42" deck with the thread rubbing against the belt and breaking it. Infuriating to diagnose and an obvious design flaw by John Deere. You'd think they'd contact all X300 owners with the 42" deck and warn them? No. You'd think my local dealer would know of the issue and could help? No. Absolutely brutal from John Deere.

To resolve it, I saw a post online from JD (apparently) to cut the bolt short. This is what I did. I cut it just flush with the nut (so I removed a solid 1/2"). I then took a file to it and smoothed it best I could. It looks like the belt now has enough room.

The main issue is upon starting it seems when you engage the deck. The torsion on the belt means the belt shakes a bit when it first starts until it settles into the full RPM and smooths out. This is when the belt rubs against the bolt. Over time, the belt degrades. Sometimes it merely kicks the belt off and you need to re-seat it. Other times, it catches the belt and it breaks.

My bolt was worn smooth on the side facing the belt - which was the final confirmation for me.

Thanks John Deere - NOT. I've also purchased about 4 belts the last few years at $80 each here in Canada. Not a happy camper.

I hope this post helps someone else with the same issue.

I have an X300 with the 42" deck and in 8 years have only replaced the belt last year. I remove my PTO each year to put on my snow blade and haven't seen any unusual wear patterns on the belt.

I have an X300 with belt problems-went to JD Dealer who replaced all of the pulleys on the deck for $475-with only a 120 hours on it, (I had fixed the belt myself on the first break). Since then I have had a belt break 7-8 times, I have taken it to my local lawn mower shop. We have filed down the intruding bolt, when powering up the blade I lower the revs and bring it back up but no help-the local guy said another X300 was having the same problem. The last belt did not show any signs of abrasion it just broke. Any other ideas?

db

I have a John Deere X380 in the shop right now. I sent it in for the 40 hour check up (my first) and on the return of the mower it was making a noise. On the second mowing the belt flew off. I am waiting on an explanation of why this may have happened, if my warranty applies (mower is less than a year old) and if they will charge me the $100 out and back delivery fee (also for the new belt). The mower was fine when I sent it in for the check. They did level the deck.

Drive belt or Deck belt? My 2010 X300 at 350 hours still has the original drive belt. I replaced the deck belt for the first time last year. You should check with the dealer that did the work and probably no charge to repair or pick up and deliver. 40 hours is way too soon for a belt to go bad.

My X300 goes through a couple of belts per year. I fixed the belt rubbing and breaking problem but it still breaks belts. I engage the deck at low rpm and disengage before raising the deck. This helps a ton? But I’ve come to the conclusion that the 17.5 hp engine has to much torque for a 1/2 inch belt. JD belts last the longest, I just ordered a Kevlar belt to try today. I’ll see how it does. the mower is actually breaking the belt under high grass load.

There is a bulletin on this. Ask the dealer. 42C deck belt failure Solution 116525. There is a new guide kit plus other instructions. You have to buy the parts from them anyways.

Thank you, tomplum I’ll check with the JD dealer !!!!

After two mowing's so far so good, the Kevlar belt has held up well even after mowing in grass high enough to kill the engine twice. Belt still looks good. I will continue to give updates through the summer on the new belts performance. I love this mower, I hope this is a solution to a problem for an otherwise great mower.

I've done a few of these upgrades. One had the belt pop again. I slid a piece of 5/16 fuel line over the post for the other idler guide. The person emailed today ad gave it a thumbs up. The rest have been good. Hokie, but...

After reading this thread it appears people find a thread title similar to their problem, then post asking about it without ever reading the thread. The help is already there folks, free for the reading.

Read it all and aplied what i learned and it stopped the freying but was still breaking belts. Mowed again today about 3 acres and the Kevlar belt is still holding. knock wood !!!!

I’ve probably bought a second X300 in bloody replacement belts at this point. Deck is flawed plain and simple. Everything here Is bandaids on a crappy design.

I've had a Wheel Horse 38" machine for over twenty four years. I started out using standard belts and getting 2-3 years life. When I tried a Kevlar belt the life increased to more than 4 years. I am hard on them because I mow a rough field that has mole hills and oak tree limbs. I run right over any oak branches that look like they are less than 1" in diameter. Some times I miss judge and hit a bigger one. Wakes me right up! I'm sold on Kevlar for my application. My mower takes 5/8" cross section belts. I don't know what others use.

If you download the engineering manuals from major manufacturers, you will find a bunch of design criteria that is frequently abused in mower deck applications. Reverse bending over too small an idler, poor alignment as the deck is raised and lowered, improper tensioning, rubbing on "belt guides", huge overloads from hitting stuff. You can find belt horse power ratings based on rpm, diameter of pulleys, and cross section of belt.

I can't comment on a particular brand of mower, but belt drive design is not rocket surgery. Part of the problem in trying to diagnose problems with mower decks is you can't see what is happening as it is working. I would not volunteer to crawl along side a mower actually in operation. You will have to look for clues: rub marks on belt guides, spindle bearings getting hot, uneven wear on pulleys, tensioner wear way off center, rub marks on stuff that should be untouched.

I've procrastinated long enough; gotta go mow.

tom

I have turned the hangar around. So far it's keeps the belt from rubbing

@geezer88 seems like a remote camera you could stick under there, with an output to a pad or laptop, might tell you a lot.