Belt problems

[moosejive16]

I'm hoping for some suggestions and maybe some insight as to what I am missing with my drive belt. When I engage the drive belt, my John Deere (100 series, 42" deck) works great, cuts fine, etc. I have recently replaced the blades, tension cable, and belt so no issues there. However, when I disengage the drive belt, there is a scratching sound, sounds similar to two stones rubbing, and the mower still cuts. I have adjusted the tension, made sure the belt is on correctly, but can't fix it. I think it has something to do with where the belt attaches to the front/bottom of the engine but don't know how to troubleshoot - any ideas? Thank you very much in advance!

 

[SPYDERLK]

Im guessing that the problem happened directly or shortly after you replaced the belt. Some belt control feature has been damaged or bypassed, allowing too much traction to persist on the engine pulley when the belt is loosened - maybe a wrap control device. -- Does the mower start up quick when you start the engine with the belt disengaged or does it spin up gradually or not at all? ... Does the noise start right away or is it synchronized to spinup? Can you observe the entire belt path while running?

 

[radios1]

the blade brake engages when you disengage the drive belt, may that is worn down to the metal. but the deck should not be able to cut grass with the drive belt disengaged!..

 

[moosejive16]

Thank you for the response - The mower spins up gradually after I start. Sometimes it takes a minute or two but eventually it always does the stone rubbing sound and then engages. The noise is the same, gradual but always there. I can see the entire belt path and there are no obstructions. I agree I think it's the pully, I just don't know how to fix it or what exactly needs to be fixed if that makes sense.

 

[moosejive16]

Are you suggesting that I should replace the blade brake? Thanks!

 

[RandyT]

the blade brakes are probably worn which could be part of the issue, but I suspect that either a non OEM belt is being used which can cause issue due to generic belts have the wrong cut angle, or the deck hangers have worn allowing the deck to move around more than normal allowing a partial engagement of the deck belt due to the deck hanging further back than what it would if new.

 

[SPYDERLK]

Thank you for the response - The mower spins up gradually after I start. Sometimes it takes a minute or two but eventually it always does the stone rubbing sound and then engages. The noise is the same, gradual but always there. I can see the entire belt path and there are no obstructions. I agree I think it's the pully, I just don't know how to fix it or what exactly needs to be fixed if that makes sense.

Are you suggesting that I should replace the blade brake? Thanks!

Im not familiar with the machine so I have to make tenuous assumptions. Your belt is disengaged by loosening? Where does the blade brake act - Does it brake one of the spindles or what? ... I can see it may make a noise when failing. ... But a loose belt transferring enough power to start up blades and then actually cut through grass seems anomalous. Can you disable the brake and determine whether the noise stops at least?

 

[moosejive16]

Thank you for the insight. I thought maybe the same, so I tried both an aftermarket no name belt as well as a John Deere - just to make sure the angle is the same, still having the same issue. The deck hangers seem to be in good shape and I've jostled it around and see limited movement. I'm stumped! I will look into the blade brakes, thank you.

 

[moosejive16]

I think the brake is my next stop, thank you again everyone!

 

[rangerfredbob]

I don't have a JD mower or anything but I do have a similar issue on my old Signature 2000 mower (Monkey wards). There's two springs on the tensioner/clutch/idler arm for the belt engagement, one pulling the pivot back to disengage the belt (broken on mine, causing this issue) and the main one for the engagement that can keep a little tension on the belt. Look for holes in the pivot bracket to see if there's a place for a spring that might be missing.

 

[radios1]

I think the brake is my next stop, thank you again everyone!

there should be enough slack in the belt when not engaged to prevent the blades from turning much, the pulley brake should stop it entirely, and quickly. perhaps the brake is so worn that it's pressing the belt against the pulley and allowing the belt to turn it.. with the tractor OFF, have someone engage and disengage the deck drive so you can see which part moves..

 

[radios1]

I can't find info at all on the 119, it's like they never made it, interesting. are you SURE you have a John Deere 119??..

 

[tomplum]

It's actually quite common that at the point where the brakes pivot on the top of the deck, that they rust and bind. Your best bet is to pull the deck to disassemble the brakes if they are binding to service them plus inspect the tension pulley bearings and spindle bearings etc. Don't be afraid to snap a pic or post the proper model number should you need more guidance.