Riding Mower Blade Mess Up - Deere LA-115

[Lonestarguy]

John Deere LA-115... 42" dual blade... So, I incidentally ran over a piece of nylon rope hidden in the grass by my grandsons ... immediately, it 'choked' the blade drive and stopped the engine dead. I removed the rope and upon engaging the blades again got a clinking/clanking noise. I find that one of the blades has zero resistance. My bet is the gear or bearing or whatever it's called that interfaces the belt to that blade has been damaged. (?) Just looking for someone to confirm this. Sound right? I think I can change it myself. I guess I need to start taking it apart, but just wondering what some of you think and if you have any advice for the repair process. Thanks!

 

[MowLife]

Definitely check the belt tension arm assembly and pulley. When blades suddenly stop the tension arm normally takes the beating.

 

[Lonestarguy]

John Deere LA-115 - Vibration after rope stopped blades (updated title)

Definitely check the belt tension arm assembly and pulley. When blades suddenly stop the tension arm normally takes the beating.

Uh, OK... LoL Unfortunately, I wouldn't know what to look for (how to check it). Dang... about to go buy a spindle. OK, I can check the belt tension I guess by engaging the blade. But again, I notice that the one spindle moves much more freely than the other... no resistance. But maybe the belt is rubbing on one more than the other?

 

[Lonestarguy]

John Deere LA-115 - Vibration after rope stopped blades (updated title)

Alright... taking a step back and considering the tensioning... With tension applied, the spindle is hard to move by hand. (Blade removed.) This seems like good news and probably shoots a hole in my hasty theory that the spindle was totally shot by this incident. (I think.) I do see that the tensioning pulley is cattywompus and the belt is not in the center of the adjacent pulley (idler pulley?). (see photo) If I assume for a moment that the spindle may be OK, I'm then perplexed about the clinking/clanking noise when the blades are engaged. I don't see how the misalignment of the pulleys could cause that noise, but I just don't know. Thoughts on the noise? Could the misalignment at the larger pulley be due to deck being lower in front than back? (potentially unrelated issue?)

So, if the tension is sufficient to make the spindle hard to turn, I guess my next step is to try to safely see if the blade is turning when engaged? I guess I can attempt to mow a couple feet and see what the cutting pattern looks like... Then it would still be a matter of what might be making the noise...



UPDATE: I did attempt to cut and apparently both blades are turning/cutting, so spindle is OK to some degree... but SOMETHING is making it run quite rough when blades engaged. The belt is 'vibrating' I guess you'd say... it's not just running smooth in the pulleys. It IS riding at the edge of the tension pulley (not centered). The engine seems fine when idling. The bad vibration starts only when blades are engaged. Could misalignment of the pulleys cause THAT much vibration or could something be bent or knocked out of whack? (well, obviously something is...)

Thanks for your patience as I step through this process.

FURTHER UPDATE: I have pulled the deck. I can pull on the belt and make the blades turn. If I were to guess, it doesn't 'feel' too bad really. The blades don't appear to be bent. When I turn the blades by hand, one offers slight resistance all the way around. The other has a spot where there is 'no resistance' for about 1/4 of a turn. I don't know if that is indicative of something or not. (damaged spindle?) Other than that, I can find no reason in/on the deck for for the bad vibration when it's running with blades engaged. Possibly the tensioner pulley bracket was slightly bent so I bent it slightly to realign it with the blade pulley. Is is slight loose but I guess it has to be to be able to move back and forth.
Thinking back, I think I did run it and engage the blades when one blade was removed from the suspect spindle and I don't recall the bad vibration at that time, but I'd have to put it all back together and try it again to be sure. If the vibration goes away, I suppose that would point to the spindle maybe??

I wanted to add a video but can't here, I guess...
1) Showed looseness/wobbly tensioner bracket (how much is normal since it has to move by nature?). I will try to get a new bracket and replace it just in case. Not sure if this could cause the bad vibration.
2) Showed brake that won't return when blade drive disengaged. Even when in proper position, it doesn't rub the pulley too well, like the other. I don't know if the rusty deck is interfering or if it was possibly bent due to the rope getting caught in the blades. (unlikely?) It was NOT contacting the pulley (angled away) the first time I saw it after removing the deck. If I loosen its mounting bolt enough, it will return as it should but I'm not comfortable leaving the bolt loosened. I will replace the brake and spring.

Thanks again for listening... I'm open to discussing or any ideas.

 

[Lonestarguy]

Re: John Deere LA-115 - Vibration after rope stopped blades (updated title)

Uh, OK... LoL Unfortunately, I wouldn't know what to look for (how to check it). Dang... about to go buy a spindle. OK, I can check the belt tension I guess by engaging the blade. But again, I notice that the one spindle moves much more freely than the other... no resistance. But maybe the belt is rubbing on one more than the other?

As mentioned in other long post updates, I did find that the brake was not contacting the pulley. The brake isn't returning when blades disengaged. I don't know how long it's been like that or if it happened due to the rope getting caught in the blades.

 

[bertsmobile1]

The pulley brake is pulled onto the pulley by a spring.
When you engage the blades the brakes are pulled back off the pulleys.
Take the deck out and watch what happens when the tensioning arm moves to engage the blades.

Take photos of everything before you undo it so you know how it goes back together.
Check the belt for a lump torn out of it.
With the deck out, move the tensioning arm to deactivate the brakes then spin each blade.
Listen for clinking, feel for smoothness.
Check the height of the blades.
They should almost touch and be at the same height
Rotate one to see if the height of each side is the same where the blades almost touch then repeat with the other side
Let us know what you find.

 

[Catherine]

:welcome:

Welcome to the forum!

I'm going to move this thread over to our John Deere section.

 

[Lonestarguy]

The pulley brake is pulled onto the pulley by a spring.
When you engage the blades the brakes are pulled back off the pulleys.
Take the deck out and watch what happens when the tensioning arm moves to engage the blades.

Take photos of everything before you undo it so you know how it goes back together.
Check the belt for a lump torn out of it.
With the deck out, move the tensioning arm to deactivate the brakes then spin each blade.
Listen for clinking, feel for smoothness.
Check the height of the blades.
They should almost touch and be at the same height
Rotate one to see if the height of each side is the same where the blades almost touch then repeat with the other side
Let us know what you find.

Thanks, I have pretty much done all that. (I have a decent techno-mechanical background so doing all this isn't over complicated for me. What I don't know, but am learning, is the theory behind all the parts.)
The belt does have a small nick in it... not a big chunk but I will replace it today when I put things back together.
Moving the tensioning arm only makes expected mechanical noises but I'm still concerned about the 'looseness' of the tensioner pulley bracket. Not knowing if it should have a bit of up and down play, I'm going to replace that as well.
The blades both seem to be at the right height, maybe 3/8" (?) from bottom of deck. They almost touch each other when passing and do not seem to move up and down so as to be warped, when rotated. As well, there is no odd sound. The spindles move freely.
I think i mentioned the pulleys move freely with some noise that seems normal. I don't think they should be totally silent, right?

I will buy what parts I think it needs and put back together and check it out and get back to you. If anyone has anything else, please feel free to chime in. If it's normal for a brake to sometimes start sticking and not returning to position, pls let me know. I will be replacing the one brake components as well.

 

[SeniorCitizen]

QUOTE:
Moving the tensioning arm only makes expected mechanical noises but I'm still concerned about the 'looseness' of the tensioner pulley bracket. Not knowing if it should have a bit of up and down play, I'm going to replace that as well.

****************************************************************
The hole the bracket is mounted in is often the problem that causes all the flopping around of the sheave and bracket.

 

[Lonestarguy]

QUOTE:
Moving the tensioning arm only makes expected mechanical noises but I'm still concerned about the 'looseness' of the tensioner pulley bracket. Not knowing if it should have a bit of up and down play, I'm going to replace that as well.

****************************************************************
The hole the bracket is mounted in is often the problem that causes all the flopping around of the sheave and bracket.

Ah, OK. Makes sense. That sounds like that would be an unresolveable deck problem then?