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formariz

What is destroying my belts?

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From the pics I have to say the belt is getting too hot and separating from the cords. Things that will cause this is not enough tension on belt. Pinched down pulleys.Or rust pitted pulleys. I. Have all so seen cracked decks on the center spinal causing belt alignment problems. Most common issue is the belt tentioner not sliding in its UHMW slides correctly.

Something is causing the belt to get too hot. That is your problem, as much rust that I see on the center pulley, I would replace that if all the rest is fine. 

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The worst thing about that deck is it looks like it has never seen the inside of a building. I think you have a lot of problems, Rust on the deck could keep the belt tightener from working as it should. The spring can get weak also I 'm sure the rust hasn't helped. Worn and rusted pulleys, I have had a set of those pulley so worn that they would not cut in heavy grass and my deck has never been left out side. From the looks of that deck I can't believe the bearing are good. Someone has already mention dull blades.

There isn't a way a deck chewing up belts like that can be quite.

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This deck came on a C125 I bought last summer. It was the first time i used and I rather liked it since it is only a 36" and gets into places I could not go with my regular 48" deck. One of my initial instincts was to change that center pulley until I Learned how hard and pricey it is.Its more than I paid for tractor. I did have intentions on checking and replacing bearings eventually.  I am just not sure now if it is worth all that trouble and expense.  Nevertheless I will be tearing into it further the next couple nights to see if I find anything as the  definite cause of problem.

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This thing is driving me absolutely insane. So I replaced all bearings , all pulleys, idler,spring, greased everything. Everything works smoothly without any wobbles or vibrations.No smell of burning rubber. Deck is extremely quite. Checked again and no twists , warps,or bends on shell. Blades are fairly new, sharp and balanced. Used it for about 4 hours by now, and I am already seeing big cracks on belt. I had Toro, Napa and four other brands of belts. Same thing happening on all of them. Is this thing possessed?  Could it be the backward bend around idler?

 

IMG_0206.JPGIMG_0205.JPG

Edited by formariz
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3 minutes ago, elcamino/wheelhorse said:

Did  you loosen the belt to take the pictures? I am still trying to figure out what is going on with your belt.

I am pulling it towards me with my hand to get it closer to camera.

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Tomorrow morning I am going to see if I can pull my belt on my deck like you did. I can not get to the tractor tonight. I am just guessing at this point but I think the belt is too loose.

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14 minutes ago, Terry M said:

Belt sized too narrow a possibility?

Nope. Got the correct belts.

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What is the diameter of the FLAT idler pulley on the spring tension arm?  If the dia is too small, that would cause the belt to bend backward at too much an angle....breaking its back.  That FLAT idler pulley s/b # 7434 for a 36" deck and it is just over 3" diameter.  MAYBE that's it.... 

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8 hours ago, daveoman1966 said:

What is the diameter of the FLAT idler pulley on the spring tension arm?  If the dia is too small, that would cause the belt to bend backward at too much an angle....breaking its back.  That FLAT idler pulley s/b # 7434 for a 36" deck and it is just over 3" diameter.  MAYBE that's it.... 

 

Had checked that already, its correct # pulley and it measures 3-1/8". I am however becoming convinced that the problem is the belt bending backwards over idler.  Too much tension in that area perhaps? Is there anyone else out there using same deck? I think my next step will be to use a cogged belt and see where that goes. This is the first time I get to examine belt early on after starting to use it, the others were totally destroyed by the time I looked at them. There is no other sign of unusual stress on belt now,just straight cracks pretty much through belt thickness .Almost like if one would take belt and totally bend it backwards .

Edited by formariz
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I'm no expert on mower decks and I don't want to give you more advice than you need here, but I see you are still having the same problem with no solution yet.  

 

So for what it's worth, I'm currently working on one of my 36" decks and I'm beginning my learning experience with repairing them.   The tensioner assembly on mine looks just like yours.  The center spindle pulley on mine had come loose, causing me to pull the cover off and check things out.  The tension spring was broken (had been attached with a zip tie on one end by PO) and the belt very worn also.  I have no idea of the age of the belt, it's a 1977 deck without the grease zerks for the spindles.  The tensioner sIide was rusted to the lower spacers and didn't appear to be sliding so I assume that's why the spring broke and possibly why the belt is worn out and maybe even effecting the loose pulley.   Probably had too much tension on the whole thing.  I wonder if too much tension is eating up your belts? :huh:

 

I did some research on the forum here last week about decks and discovered the replacement nylon washers and spacers, available from Glen Pettit, that no one has mentioned on this thread yet.  My deck had the original metal spacers and washers and lots of rust.  The kit is listed on this page;

I also purchased a new spring # 100071 and belt # 8411, genuine Toro parts I found on eBay.  I just received the washer kit from Glen yesterday, so I've not got it put back together yet.  I'm hoping this will solve my problems.  I just need a chance to work on it again.  I'd be glad to report my results. 

 

I'm sorry if I may not have told you anything you didn't already know.   There is a solution, we've just not discovered it yet!  

:twocents-02cents:

 

 

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This deck did have the plastic washers and spacers already which I did replace with new ones anyway. The tensioning assembly was functioning properly before and also now with everything new. I am also thinking one could replace the specified spring with a weaker one to reduce the stress on the belt when going around backwards on idler .

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It's certainly is a puzzler.  What part no. is your belt?

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It definitely looks like the belt is overheating. I think the back bending is only serving to make a bad problem worse and is not actually the cause. Any idea what speed your belt is running at (or mule drive)?

 

My suggestion is to clean the pulleys and put layout dye or something similar on them and turn the drive pulley by hand to see if you can see any points that are wearing abnormally fast. If nothing, run it under power for several seconds at a time. Don't know if this will take all the dye off quickly or not.

 

It really looks like one or more pulleys is seizing intermittently at operating speeds.

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Pulleys are definitely not seizing intermittently at operating speeds. I have been looking at them for quite sometime running full speed and they are not seizing. While cutting I can't be sure but stopped with deck engaged they are not .

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25 minutes ago, clip said:

It really looks like one or more pulleys is seizing intermittently at operating speeds

 

I agree but wouldn't that mean the growling bearing noise or some belt squealing or smoke? Makes no sense!?!?! :confusion-scratchheadblue:

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I have a 36 inch Rd deck . I checked mine out this morning . One thing I noticed was your idler pulley seemed taller ( thicker ) then mine. SO I measured it, my idler pulley is 3 1/8" diameter and has a thickness of 7/8 inch. Measured from the outside. The idler pulley number is 112426. This is the item number on the packing list when I ordered it. The belt is a number 8411. Also my belt is very tight , I can not press it together like you did in you photo. The belt has been one the deck for 3 or 4 years. 

Edited by elcamino/wheelhorse

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5 minutes ago, WHX61/3 said:

 

I agree but wouldn't that mean the growling bearing noise or some belt squealing or smoke? Makes no sense!?!?! :confusion-scratchheadblue:

That's what I've always associated with failing rotating shafts. I don't think it's an issue of continuous drag because you'd see low-grade damage across the entire belt and lots of smoke. And the mower deck belt is totally disconnected from any powered rotating pulleys, so my conclusion would be all pulleys are moving the same speed, except one or more moving slower because they can't move faster. 

 

I've got a 42" deck and belt routing is different. There's no way to mix up routing on a 36" deck is there? Highly doubtful but no clue what's chewing up belts.

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Yeah something doesn't look right but it could just me the way I am seeing it. looks close to itself where I have it circled. Also looks like the tension spring is pulling the belt  the wrong way? I would have guessed you checked  the slider is not hanging up

IMG_0205_JPG_99b5214139a93ffeb51509926e3764f0.jpg

2 hours ago, formariz said:

The tensioning assembly was functioning properly before and also now with everything new. I am also thinking one could replace the specified spring with a weaker one to reduce the stress on the belt when going around backwards on idler

Never mid Cas just caught this post

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This is just my :twocents-02cents: , but I think the belt is too loose and it is moving up and down on the idler pulley. As it moves up and down the inside edge of the belt is hitting the outside edge of the next pulley. The causes small nicks in the belt until a section of the belt tears off. Based on his photos the belt appears to be on the pulleys in the correct order.

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So I took deck off AGAIN. I am now a real expert at putting this thing in and out in 2 minutes or less. Again tensioner works well and everything rotates evenly and smoothly. All pulleys are new with  about 4 hours of work. Is Highly polished surface on them  an indication of any slippage perhaps? They were all black to start with. Pulley from mule drive only shows mild polishing and not on entire surface. I can fairly easily push or pull belt and move tensioner back and forth. Spring is new and I could basically do the same with old one.IMG_0212.JPGIMG_0213.JPGIMG_0207.JPGIMG_0208.JPGIMG_0209.JPG

IMG_0210.MOV

Edited by formariz
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53 minutes ago, formariz said:

indication of any slippage perhaps

Gotta be, looks like belt has got good turns on the pullies. I would try a stronger, maybe shorter, spring but use the old belt to see if it gets any worse. No sense in trashing another new belt.. I know they don't give them away.  On mine when I tie into longer grass or rough cutting that tension bar starts jumping like crazy causing the belt to slip. Different spring has gotta help. Kinda looks like in your video it's too easy to push or flex the belt.

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