Good point. Make sure the pulleys are offset in the correct direction so the belt runs in a straight line.
Craftsman deck exploding
- Thread starter Craftsman Garage
- Start date
Are you saying that the problem happens when you start moving forward but not when sitting still?Tried again after I fixed the tangled belt, and it worked even at idle pretty good for about 5 minutes , I throttle up about halfway, let off brake and as soon as I started going BANG…and it happened againWill order new Kevlar belt and will update soon
I've often found that if I can work on items of this nature that getting them up on a bench, unattached to the tractor is easiest. As I've aged this helps even more. The 60" on the 430 is too heavy to lift alone so I use the cherry picker.
It took 18 replies before someone suggested blade balance/installation causing the vibration?
Here's a suggestion:
Take the deck off the tractor and elevate it, if for no other reason than more comfort. Remove the blades, remove the belt completely, and if possible, remove the blade safety brakes so that the spindles can spin freely. Turn each one independently by hand to verify that 1) there is no noise, 2) there is no 'slop' or slack, 3) the pulleys do not wobble on the shaft, 4) the shafts do not have any axial run-out (wobble because they're bent). Inspect the blade end of each spindle to make sure that the blades have not spun on the spindles. That is usually very obvious on both the blades and spindles. If there are zerk (grease) fittings on the spindle housings, pump 'em full of grease until you see it ooze out at either the top or bottom bearing. If it's on the spindle shaft, same goes. Some have the zerks on the spindle shaft, and I highly recommend avoiding those. There's a lot less metal in the spindle shaft (because of the grease galley) and they will break off much easier, typically between the pulley nut threads and splines. An impact (stump/rock) will cause the belt to snap the pulley right off where the greaseless ones or the ones with the zerks in the housing hold up much better.
Verify all idler pulleys turn freely and make no bearing noise. Check all tensioner (idler) springs to verify none is damaged or broken. If you find no suspect bearings, springs, or shafts, reassemble the deck, but do not yet re-install the blades.
Install the deck under the tractor, and run it 'no-load' sans blades to check for noise and belt lash. You'll be able to hear all mechanical noises from the deck drive system, or better yet, hear nothing other than the engine when you engage the PTO. Have someone video the drive belts for you to look at, or maybe borrow a camera you can stick on the deck. Some belt lash is completely normal because they run at relatively low tension and all internal combustion engines have a pulsating torque. Most of the lashing will be on one side which is where the tensioning idlers typically are.
If you are noise and vibration free at this point, re-install the blades. Hopefully you have a mower jack so you don't have to pull the deck again. First, check the balance of each blade. You can do this with a string with a nail tied in it. Just lift the blade with the string. If it tilts to one side, it's heavy on that side. Taking a little more steel off by sharpening typically helps. Mount the blades and make sure that the blades are properly seated on any keying on the spindle shafts, and flat on the flange. Normally if the blade is keyed to the spindle there is a cup shaped spacer or bell washer to keep it on the splines. Make absolutely sure the blade does not turn on the splines while you are tightening it. I find running the bolt in by hand rather than impact works better. Impact is fine for taking up the slack, but do not tighten that bolt with an impact. There is usually a torque specification in your mower's literature, somewhere. Turn the blades (LH and center, then RH and center) to align the tips pointing at the other spindle. Verify the blade tips are very closely matched. Turn both 180 degrees, and check again. If there is a difference in the way the tips meet, you have a bent blade or bent arbor. A slight misalignment could be deck shape tolerance. Check both sides against the center blade this way. If you don't find any significant misalignment, the deck should not vibrate significantly. If it does, then the problem is blade balance. If you have more than one blade out of balance, you'll hear/feel a low frequency harmonic vibration that is speed related. You may get some vibration if the blade tips are passing close as well, but nothing to worry about. The shorter the blades, the faster they have to turn to keep tip speed up enough to move the cut grass. That's one of the disadvantages of a 3-blade deck. I have a 46" deck with two blades which runs at a much lower rotational speed. Balance is MUCH more critical with longer blades. Bent is bent, nothing to do for it but replace it.
Here's a suggestion:
Take the deck off the tractor and elevate it, if for no other reason than more comfort. Remove the blades, remove the belt completely, and if possible, remove the blade safety brakes so that the spindles can spin freely. Turn each one independently by hand to verify that 1) there is no noise, 2) there is no 'slop' or slack, 3) the pulleys do not wobble on the shaft, 4) the shafts do not have any axial run-out (wobble because they're bent). Inspect the blade end of each spindle to make sure that the blades have not spun on the spindles. That is usually very obvious on both the blades and spindles. If there are zerk (grease) fittings on the spindle housings, pump 'em full of grease until you see it ooze out at either the top or bottom bearing. If it's on the spindle shaft, same goes. Some have the zerks on the spindle shaft, and I highly recommend avoiding those. There's a lot less metal in the spindle shaft (because of the grease galley) and they will break off much easier, typically between the pulley nut threads and splines. An impact (stump/rock) will cause the belt to snap the pulley right off where the greaseless ones or the ones with the zerks in the housing hold up much better.
Verify all idler pulleys turn freely and make no bearing noise. Check all tensioner (idler) springs to verify none is damaged or broken. If you find no suspect bearings, springs, or shafts, reassemble the deck, but do not yet re-install the blades.
Install the deck under the tractor, and run it 'no-load' sans blades to check for noise and belt lash. You'll be able to hear all mechanical noises from the deck drive system, or better yet, hear nothing other than the engine when you engage the PTO. Have someone video the drive belts for you to look at, or maybe borrow a camera you can stick on the deck. Some belt lash is completely normal because they run at relatively low tension and all internal combustion engines have a pulsating torque. Most of the lashing will be on one side which is where the tensioning idlers typically are.
If you are noise and vibration free at this point, re-install the blades. Hopefully you have a mower jack so you don't have to pull the deck again. First, check the balance of each blade. You can do this with a string with a nail tied in it. Just lift the blade with the string. If it tilts to one side, it's heavy on that side. Taking a little more steel off by sharpening typically helps. Mount the blades and make sure that the blades are properly seated on any keying on the spindle shafts, and flat on the flange. Normally if the blade is keyed to the spindle there is a cup shaped spacer or bell washer to keep it on the splines. Make absolutely sure the blade does not turn on the splines while you are tightening it. I find running the bolt in by hand rather than impact works better. Impact is fine for taking up the slack, but do not tighten that bolt with an impact. There is usually a torque specification in your mower's literature, somewhere. Turn the blades (LH and center, then RH and center) to align the tips pointing at the other spindle. Verify the blade tips are very closely matched. Turn both 180 degrees, and check again. If there is a difference in the way the tips meet, you have a bent blade or bent arbor. A slight misalignment could be deck shape tolerance. Check both sides against the center blade this way. If you don't find any significant misalignment, the deck should not vibrate significantly. If it does, then the problem is blade balance. If you have more than one blade out of balance, you'll hear/feel a low frequency harmonic vibration that is speed related. You may get some vibration if the blade tips are passing close as well, but nothing to worry about. The shorter the blades, the faster they have to turn to keep tip speed up enough to move the cut grass. That's one of the disadvantages of a 3-blade deck. I have a 46" deck with two blades which runs at a much lower rotational speed. Balance is MUCH more critical with longer blades. Bent is bent, nothing to do for it but replace it.
Not once but several times when connecting that spring I rerouted it on the wrong side of the belt. In my case engine bogged down severely and I smelled burnt rubber. Now I tension the belt with mower not running and check if there is interferance between the belt and tensioner spring.
Husq YTH 2454 2007.Same problem. did 3 things to solve.
1) Replace belt as it probably was cut and twisted when it jammed between keeper and pulley edge.
Will now keep trying to jump and jam on you no matter what you do (IMHO), and experience.
2) As above, get new oem tensioner spring, or, as I did, add a 'helper' spring to the original to keep good tension on belt/idler pulleys.
3) This is key. Design of the belt keeper (shown in photo) is terrible. Too much room for belt to get off pulley and bend the keeper up so that belt is able to jump off idler when elec clutch engages, especially if the deck is in lowered position (large down angle on belt resulting in that 'belt jump' on engagement. I bent the horizontal leg of the keeper enough so that the vertical leg extended further thru the hole in the mounting plate, then threaded the end and installed a jam nut from underneath. No more belt excursions in the last 3 years. Went thru 3 belt keepers before this, usually 1st or second mow right after taking out of winter storage.
As an afterthought, check the belt keeper on the mower frame under the elec clutch for damage or missing (?) as a problem here will also introduce 'belt jump'. good luck!
It really shouldn't be rocket science.
Most of the time when a belt gets damaged quickly it is because it is routed improperly or going around the wrong side of a keeper etc or rubbing on something.
You always need to thoroughly inspect the routing and reach underneath and move one or both of the blades by hand to get everything to rotate so you can watch it moving around etc.
THEN if you're not using OEM belts you're wasting your time.
Far too many problems and busted belts in just minutes or belts only lasting short periods of time or not even gripping properly or disengaging properly on ones with a lever PTO have been attributed to non OEM belts so I won't mess with them at all.
Most of the time when a belt gets damaged quickly it is because it is routed improperly or going around the wrong side of a keeper etc or rubbing on something.
You always need to thoroughly inspect the routing and reach underneath and move one or both of the blades by hand to get everything to rotate so you can watch it moving around etc.
THEN if you're not using OEM belts you're wasting your time.
Far too many problems and busted belts in just minutes or belts only lasting short periods of time or not even gripping properly or disengaging properly on ones with a lever PTO have been attributed to non OEM belts so I won't mess with them at all.
A mower was brought to the shop with same problem.The belt was routed wrong.The flat side of the belt was rubbing against a guide.The Kevlar belt was still good.Tough stuff.It would stall when deck was engaged.My guess is a mis-routed belt,based on years of experience.