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Discussion Starter · #1 ·
Just got this one and it didnt have a drive belt from motor to deck. -- no problem, order one and all is good,---well for 28 hours run time! Belt exploades! We get a longer one--- runs a couple hours then streaches too far. Order 1 a half inch longer than the 79.5 that is too short but factory CLAIMS it takes and put it on.
after a half hour or so the belt gets hot and smells like tires burning! WHY? pulleys are lined up as far as I can see. I reset the deck angles a little,---didnt help.
Mower was on an auction for that belt problem I guess! ---- has 460 hours on the meter, mower looks like new,---beats me as to whats wrong! any ideas??? thanks!
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Just got this one and it didnt have a drive belt from motor to deck. -- no problem, order one and all is good,---well for 28 hours run time! Belt exploades! We get a longer one--- runs a couple hours then streaches too far. Order 1 a half inch longer than the 79.5 that is too short but factory CLAIMS it takes and put it on.
after a half hour or so the belt gets hot and smells like tires burning! WHY? pulleys are lined up as far as I can see. I reset the deck angles a little,---didnt help.
Mower was on an auction for that belt problem I guess! ---- has 460 hours on the meter, mower looks like new,---beats me as to whats wrong! any ideas??? thanks! View attachment 2557042

View attachment 2557043
Hot belts, sounds like a frozen bearing on one of the pulleys. W
Could also cause belts to jump off. Course you have probably checked that already.


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First off, I love those tires. Next set for my ZT2 will be those!!

Hot belts that get hot, and small like they are burning are slipping or being rubbed by something during operation.

With the mower belt and protective sheet metal off, rotate each mower blade by hand. Those CC deck spindles should spin freely, with just a nudge from your pinky finger, and rotate through 360 degrees with no tight spots, no grinding. If those are OK, inspect each tensioner pulley on top of the deck to be sure each rotates freely with no wobbling and no resistance. Look for anything that might touch the belt during operation. A bent belt keeper rubbing on the back of a belt can introduce a lot of friction if rubbing hard on the belt.

Also, check the width of the V pulleys. Be sure your belt fits those. Belt should "wedge" between the sides of the V pulleys and never bottom out in them, otherwise you get slippage and heat like you mentioned.

I think there are 3 idler/tensioner pulleys that ride on the back side of the mower belt. If anyone of them is stuck, it will result in what you have, melted belts that blow apart eventually from the heat and friction. Also be sure the tensioner pulley's arm moves freely and keeps the belt tight via its spring.

I'm not sure, but this is a 48" CC deck for the Zforce model. It shows 2 idler, and 1 tensioner pulleys, (red check marks) plus the 3 spindle drive pulleys. My CC Ultima 60" deck is slightly different but not much.

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Have a close look at all of the pulleys and verify they are all free and run true. I think you may find that one or more are frozen or at least stiff, and burning up your belts from slippage and friction.

Let us know what you find. Good luck.
 

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A second thought. Years ago, I had a mower that I tried to fix and return to service. No belt on it. When I got a new belt, by some trick, I managed to get the belt installed, and the blades rotating. I didn't realize that I had it routed wrong. It was one of the idler pulleys. I had the V part of the belt riding on the FLAT idler pulley. ( Don' ask how, this is embarrassing enough as it is). When the belt rode over that flat pulley, it would twist and lay on its side as it went past that pulley. Took a little while but all that twisting and untwisting heated the belt and off it came. Curled up in a tangled wad, like a set of Christmas lights. Hot, and frayed it was junk.

Long story, short point. Be sure routing is correct. Idler pulleys with flat bottoms ride on the back of the belt.
 

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Discussion Starter · #5 ·
engine to center spindle belt is the problem child, deck belt runs fine and cool. --all spindles rotate in the wind with the belts off and mower turned on its side, --- somebody put all 3 idler pulleys that you marked in your pic. on new. ( old ones were probably good)' Its a mystery to me! nothing is rubbing, ---seams to me that the belt is way too tight causing it to get hot. The longer one I tried did start rubbing on the inside after an hour of runtime. This 80" one is tight and not rubbing on anything that I can see. everything is open under there.
It has a poor design for adjustments so you are very limited on what you can do. Still lookin at it as the grass grows taller every day! LOL!!
 

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Ah,I see. Is the pic below representative of your deck? I think the 48" has similar two belt system. To assist, would it be possible to post a couple of close up pics of the PTO, and the belt path all the way to the main pulley on the deck? Others with the same deck may be able to spot something or make specific suggestions for you.

If the engine to deck belt is heating up, is there any damage or deflection in the engine exhaust system that might directing exhaust at the belt path?

Only other thing I can think of would be if the PTO is overheating somehow. But I don't have much expertise in PTOs except for having replaced a couple of them.


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Discussion Starter · #7 ·
Ya! thats the 2 belt kind like mine! ---they had 44 -- 48 -- and I think 50 inchers for that series. Mine has a long handle stickin out the left side for the tightner which is spring loaded. Will try to get some pix. of the underside in a couple of days and post them.
 

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Is this more like your arrangement with belt #40 (top belt) being the problem child? From this diagram, it looks like there should be one tensioner pulley riding on the back of the main belt, but doesn't show it in place.

Doesn't leave much in the way of possible causes.
1) wrong belt, either width or length. 2) PTO overheating, maybe not locking up, cooking the belt, or 3) Something is binding up upon use and causing the belt to slip.

Nice looking machine, sure hope you can diagnose and fix the problem.
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Discussion Starter · #9 ·
Ya thats like mine! A member over on smokestak found a manual for it and I downloaded it. NOW --- they show a 5/8" x 82.5" belt #00050441 and I had an 82" one on there and that was too long. after an hour or less it started rubbing together on the inside and there is VERY little adjustments in any direction on there.
I went with 80" and yesterday I did mow for a few hours AFTER removing the tightner spring/and handle so the belt is not really touching anything cept the pulley without any pressure on it. Now I gotta take the rest of the tightner stuff off so nothing will touch it. belt got fairly warm but the stupid electric clutch gets hot,-- BUT it's not slipping so dont know what that is all about! Hmmmm! Little by little maybe we can figure it out just by trying different stuff!
 

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Discussion Starter · #10 ·
got a couple pix but cant see much down the line. this one probably shows the step down the belt has to run the best.

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the second pix. is from the front and I couldnt get an angle clear down the line from there.

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Are you certain that flat pulley isn't freezing up? Maybe it is just the lighting but I blew up the pic and it looks like there is shiny wear on part of it but not on all of it. Looks like the shiny part ends at about 7 o'clock on the pulley where some surface rust seems to appear. See red circle and the arrow. You can have a close look and confirm if it is just a pic issue or if there is uneven wear on that pulley. Also, again maybe it is just the lighting, but the belt seems a bit scuffed at the top edge, which somewhat matches the shiny part on the flat pulley . Maybe I'm just just seeing things, wouldn't be the first time. 😉

If that isn't it, then I guess I'm stumped too. Not sure how hot PTOs get under normal circumstances. Certainly there is the electro magnet in the PTO, and some heat transfer from the engine, but neither should heat a belt to the point of smelling hot or burning. That is usually from friction.

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Discussion Starter · #12 ·
Ya, I noticed the pulley face and it does spin free. I dont know why the rust pattern is on the face of it. The long 82" belt I tried started to eat off one edge and I think that is what happened to the first one.
Wonder if it has the right clutch to begin with? pulley should hang down a couple inches lower in my book, then it would come into a more level plane.
 

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Hard to say if the PTO is correct unless you find a part number on it and compare to the CC parts list for this machine. You might have luck looking up the correct one on line and seeing if the image of that matches what you have on your machine.

O course, that primary mower drive belt will have to take some vertical misalignment as you move the deck cut height from low to high and back, and when raising it up all the way. But, I wouldn't think there should be very much wear on one edge. Maybe with the machine off, someone could raise and lower the deck while you visually check to see if there is anything coming into contact with the belt throughout the deck's up and down movement, or if the belt is severely off plane at any position.

Here is one from left field: Is the deck leveled with the front edge 1/4 inch lower than the rear edge? I've seen decks adjusted way out of level with drive pulleys pointing downward at the rear edge, making them prone to popping off at lower deck settings. Not a likely thing, but with prior owners...who knows...check it out.
 

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Looks like it's not aligned right with the way it wearing on the top side. It doesn't take much to have things go wrong when it come to belts.
 

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got a couple pix but cant see much down the line. this one probably shows the step down the belt has to run the best.

View attachment 2557734
the second pix. is from the front and I couldnt get an angle clear down the line from there.

View attachment 2557735
From the first picture it looks like the belt drops a lot. That would put a lot of stress on that side of the belt. Not sure what deck setting you were at when you took the picture. Belts should run near center and straight at the middle deck settings, then go slightly up and down from there going from full up deck position to lowest deck position. I think you were right when you questioned the PTO being the right one.
 

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Discussion Starter · #16 ·
belts never come off no matter what height I run the deck,----just wear fast then explode! I took part of the tightner off and the pulley is hanging loose under,--- gonna take the rest of the tightner off today when the deck is out for blade sharpening. Nothing rubbing since there is nothing anywhere near the main belt.
The deck has no adjustment left for lowering the front anymore than whats in the pix.
I still think the motor clutch pulley should hang at least 2 or 3 inches lower than it does.
Guess this is NOT IH cc but mtd design, and mtd always made JUNK equipment!
 

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Is there some way for you to check the PTO that is on your machine to be sure it is the correct one for this machine? Especially since you observed that it looks like it should be 2 or 3 inches lower. That is a lot in terms of belt alignment.
 

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Discussion Starter · #18 ·
mtd CLAIMS this is the right one! Its the one they chose to slap on this model! ---Poor design on mtd's part but thats mtd for you! Make junk and shove it out the door!
 

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Here's what I would do......
It's going to sound stupid, but sometimes for me stupid things work.
1) blow grass off deck
2) remove belt
3) remove idler pulley
I assume(?) spindles don't have grease fittings? If so...lube
4) idler I'd oil bearings if possible. Lightly spray paint surface (black is fine, I'll explain later)
5) now going by diagram be 100% sure all parts are there. Someone could have left off a spindle bracket, something installed incorrectly, a bent idler arm, etc. Be 100% sure spindle & PTO pulleys are straight, clean, don't wobble, etc.
6) use specified belt (82.5" if supposed to be). Green belt (not the black $8 automotive ones).
7) idler & belt on, check alignment. You should be able to move by hand...or helper move & you check.
If everything is correct, idler should contact back of belt with spring pressure.
8) Last start, helper in seat, engage PTO while you carefully watch belt. Everything should be smooth...no wobble, jumping, etc.
Shut off. Check idler pulley wear pattern. Easy to see since paint will be worn off. Belt should be riding in center. ("The long 82" belt I tried started to eat off one edge") seems to be the trouble...should never do that.
Something is obviously bent or out of alignment.

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