62c mower belt flapping

[megotatractor]

Hello,
Noticed the other day while the wife was mowing that the belt on the 62c deck was flapping against the gearbox bracket, and of course the plastic sheave covers are worn and destroyed basically. (due to injury to my ribs in a tornado vs. truck rollover incident I'm not able to mow for now) I assumed there would be something in the sheave but there isn't, I checked all three. Tensioner seems fine. I can't imagine what 's causing the belt to flap like that. Any suggestions? I have inspected the sheaves, all fine, not bent or anything. My 2210 is showing over 545 hours, six years old. I would guess close to 500 hours were mowing. I see the price of a new belt is over 80 bucks and would appreciate some suggestions before I blindly replace it hoping to fix the flapping problem. Note, a few years ago I did get a piece of wood stuck in the mower blades and may have slipped the belt in one spot, could that have gotten worse with wear? Also, there is a spot of rust deep in the left sheave from years ago I got lazy putting it away in the fall. I should also note that the belt has been flapping slightly since new for years wearing away the plastic covers, but it was acceptable in my opinion, but now flapping against that bracket is not tolerable. How much does that belt normally flap if at all? Anyone else have the belt eat away at those plastic covers?

 

[Rotormech]

I currently have 90 hrs on mine and the belt is flapping to the point where it has cut into the plastic pulley guards on both sides. It is leaving black marks on top of mower deck also. I haven't had time to really look into this though.

 

[megotatractor]

I just finished taking the mower completely apart. Inspected every inch of the belt and looks perfect to me - aside from some small abrasions from flapping against that bracket. The sheaves, the outer ones especially, have an ever so slight wobble to them, probably can't be helped???? The blades are perfectly balanced as far as I can tell. I'm stumped, I guess I'll call the dealer and see if they can offer any suggestion.

 

[jsb2b]

I have 3 years of mowing on my 2305 and have noticed that when I get into higher than normal grass(3"+), the sound of the mower changes and in normal mowing, the deck doesn't cut as evenly as it did when new(it never did cut to good where the wheels compressed the grass). I removed the belt guards when I first got the tractor because I know they get filled with clippings, leaves and twigs.

So now I notice that the belt is flapping and really don't like the idea of spending $80 on a belt. The tensioner spring may be weak but the idler arm is not to the stop so I assume it is in specs. Does anyone know how many inch/pounds of deflection the belt should have and where to take the measurement???

I was thinking of rolling the belt over to see if it had more "grip" on the pulleys. I suppose the best thing to do is take the belt off and use a belt measurer(if I could find one) and compare it to a new belt(if my JD dealer had a belt measuring tool).

I think a belt should last for years unless you are brush hogging with the 62C...

 

[megotatractor]

jsb2b, Mine is 6 1/2 years, 500 hours on the original belt. I spoke with the service tech at JD and he was also stumped and unaware of a flopping problem with the 62c deck. I'm guessing because he doesn't mow with one. His first thoughts were with the tensioner and its spring. It's possible I suppose that after 6 years the spring could become weakened. He also suspected something wedged in one of the sheaves which is not the case. The third guess was something about the belt. His best suggestion was to bring in the belt and compare to a new one and measure it. The dealer closed at noon today so didn't have time to go see them so I remounted the deck without the guards and mowed for an hour. I notice the extreme flopping is only intermittent, but will investigate further Monday as I do not want to spend $80 on a belt until I know what's happening. Perhaps I will get by with a couple new sheaves.

 

[thatguy]

What are 'sheaves'??

Brian

 

[megotatractor]

Sheaves - could also be called pulleys, the wheel driven by a belt.

 

[kennyd]

Sheaves - could also be called pulleys, the wheel driven by a belt. see diagram ; http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.HomePageServlet

You can't link to JDParts because it requires a login

 

[megotatractor]

ooops, that's right.

 

[thatguy]

thanks.. I was drawing a huge blank on 'sheaves'


brian

 

[ADin]

megotatractor,

Keep us posted on what you find and count me in on as having near identical symptoms. I also notice things seems a bit louder over time. To make things worse, I accidentally hit a stump this past spring and ended up bending a blade pretty good. This was the impetus for the start of my investigations, I ended up replacing blades and using the 2" flanges + long pipe trick to restraighten the deck as the stump hit caused a slight deck deflection. My mower performance was fixed and the noise improved, but still louder than I thought I had remembered when new. I found I could grab the blade (or sprindle from below), and under the right conditions product a very slight motion and click type noise (imagine applying slight up/down force on the blade, not rotation, which would cause a sideways deflection on the spindle shaft). Perhaps at most 1/16" deflection at the blade tips. I had about 270 hours (majority mowing) at that time and do a pretty good job keeping the spindles greased, but I thought perhaps there was spindle wear. I inspected the spindle, found nothing, but ultimately replaced the spindle bearings and shaft. Still no change and afterwards, I founds I could still produce the slight click noise so I assume it is result of natural play in the bearings, though deflection may be a touch less, but it's hard to say. I then determined that at just the right spot of blade rotation I could get one of the other spindles to also make the clicking noise.

The belt had rubbed the deck on the back left side as looking down from the seat as well as the gear box bracket a bit, but I think that it only rubbed when the blade was bent. The belt seems to still be flapping more than I think it should, but I don't think it's actually rubbing anything currently. I also thought about and had suspicion of the tensioner spring, as I couldn't find anything else to point to, however, I doubt this will be the issue as even when I artificially "assist" the tensioner spring, I don't seem to see an appreciable difference in deflection of the belt. I had left this item on my to do list, but tabled it for the past couple of months. This thread has got me back on the topic as this is annoying to the engineering side of me not being able to put this to bed.

My current guess is that the belt is naturally a little flapping and with age we are getting additional vibration pulses through the pto shaft aggravating the situation. I would like to confirm by checking out a new JD2305 w/ 62c at that dealership to compare (or if someone with low hours could respond).

 

[megotatractor]

AD, I haven't noticed increased noise. The deck does seem louder if there' s buildup of crud underneath.. I've always had a slight flap to the belt and I think it's normal. BUT when it starts slapping that bracket loudly that's extreme and could damage the belt. I do see that the outer sheaves (pulleys) have a slight wobble to them and some rust spotting which could possibly contribute. Could they have been warped by heat or having debris wedged in them? I did also notice when I had the belt off that two of the three bearings are a bit noisy when spun by hand. And like yours there is a small amount of play and a "click" in all three bearings. I may plan on changing out the noisy ones at the end of the season . Tomorrow I'm going to take the tensioner spring to JD and compare to a new one, measure the belt against a new one, and have the service guy look at the two sheaves which I'm considering changing. I seem to remember when the deck was new it was hard to get the belt off, now it seems easy; belt stretched? spring worn?
I did have a vibration to the deck yesterday which was solved by changing out the worn blades to a back-up set of sharp, balanced blades I had.

 

[ADin]

Hmmm, does sound like you do have something worse going on. My noise/vibration seems worse but I can't say for certainty that it is. It may be mostly sensitivity increasing over time. I do remember the JD2305 sounding so quiet when I first got it, but it may have only been my perception of it relative to the 335 I was migrating from.

Can/do belts develop unseen hard spots over time or similar to tires if they sit for awhile? It seems hard to imagine, but it wouldn't take much to increase the already flapping condition.

Also, I know you said the blades were balanced, but you might try an experiment running with the blades removed to see how/if that affects anything as I would think that would pretty much eliminate forces resulting from the blades or spindle bearings.

Good luck...

 

[jsb2b]

As you pull on the belt, the tension spring length increases so as the belt wears, the spring length decreases. The distance between number 9 in the picture to the rubber stop would be small if the belt were very tight. My distance from the number 9 square steel bar to the rubber stop is about 2 inches. What is it on a new deck???

Also, the L shaped bracket #3 has 2 holes in it. Mine has the bolt in the hole nearest the spring. The picture shows the bolt on the hole away from the spring. This would provide more belt tension. Which is the right hole to bolt the L bracket to the square steel bar????

 

[megotatractor]

jsb2b, you made me look. I measure 2 3/4 inches from the bar to the rubber stop. And the diagram appears to be in error- the #3 part has 1 bolt hole and it is midway of the part, what they show as where the bolt goes in the diagram is actually just a detent on mine to keep the part from slipping.

 

[jsb2b]

jsb2b, you made me look. I measure 2 3/4 inches from the bar to the rubber stop. And the diagram appears to be in error- the #3 part has 1 bolt hole and it is midway of the part, what they show as where the bolt goes in the diagram is actually just a detent on mine to keep the part from slipping.

Ahh... My old eyes are failing me. What I thought was another hole is indeed just a detent. I measured 2-1/4" from bar to rubber stop. I guess we need someone to pony up $81 and see if it fixes the problem!!!

 

[megotatractor]

I found the specs for the belt on jdparts and measured the width and thickness, thickness is almost new, width is down by about 1/16". I doubt it has stretched much so I won't try to measure length. FYI belt specs are; length, 128.12, width .63" or 5/8", thickness .58 or about 9/16". I'm going to watch this closely and try to finish the season. Then I don't know, maybe a nylon guide to keep it from slapping that bracket? End of season I may change out the questionable bearings and wobbly sheaves and see how it runs. I wish I could find a spec that says "this belt should be replaced if it measures?"

 

[ADin]

Ok, I think I have found part of my problem. Upon much closer inspection with a square of the sheaves I determined that two of the sheaves were perhaps almost 1/16" from being perfectly round. Measuring the sheave thickness with a caliper I was able to confirm that the sheave was thicker (spread wider) where the radius was the smallest. I have taken the first off and with some very gentle persuasion with the vise was able to recompress the sheave just a tad back to uniform thickness. I've reinstalled and it is now nearly a perfect circle (less than 1/32"). The nut on the second sheave stubbornly does not want to loosen so I will tackle it when I get more time tomorrow. Once I get the second one corrected, blades cleaned and sharpened, I will report back as to the level of improvement. It may not solve fully solve my problem, but I figure even this 1/16" error in the radius of the sheave will translate into larger errors in belt oscillations (~1/4 inch linear) and would be compounded depending correlations between errors in multiple sheaves. The spring will help dampen, especially between the first and middle sheaves, but given the belt to sheave friction and the mass of the blades providing inertia, I can see where greater forces would be applied between the middle to third, and third back to first.

Any case, just a lot of conjecture at this point, we will see once its reassembled.

BTW - Is there an easy way to break loose the nut on a sheave? I'm assuming there is a tool which attaches to the holes.

 

[jsb2b]

Easiest way to break a nut loose is an impact wrench. Use one on alternator pulleys all the time. A pre-soak of Liquid Wrench is always a help if you suspect any corrosion. :thumbsup:

 

[megotatractor]

My impact wrench is a POS that will not loosen anything. Except the blades! LOL I rattled on the sheave nut and the blade fell off underneath! LOL! Im almost convinced the sheaves have gotten warped or bent somehow and that is contributing. I will have to try other means of loosening that nut end of season.