Yep my Road King is quieter w/o the shield on. Also my side-by-side which is one reason I remove the low windshield and roof as soon as good weather comes, doing so makes quite a noticeable decrease in engine/transmission and whatever else noise.
L2501 6hrs new rattle
- Thread starter lphegner
- Start date
I cranked mine today and remembered this thread. I intentionally pushed the clutch in and there is a difference in sound, just like your video.
Yes mine is exactly the same - and I never assumed any issue. It has performed perfectly in its first 32 hours of life. It had this difference in sound from day one. I never thought anything of it. Still hope the OP will report back with what he finds out though form the dealer.
There is clearance between gears in the main transmission. There has to be for lubrication purposes.
What you are hearing is the gears rattling against themselves in the main transmission (H-M-L gear). There is nothing wrong. When you mash the clutch pedal down, the main transmission STOPS, so it can't rattle if the shafts and gears are not turning. The rattling is caused by the engine; 3 cylinder. Every Kubota diesel engine has 4 strokes per cycle, an in the case of a 3 cylinder, it fires one cylinder every 240 degrees of crankshaft rotation. When the fuel is ignited, the crankshaft speed increases slightly, until approximately 90-120 degrees of crankshaft rotation, where the crankshaft tends to level off, then eventually slows down again as another cylinder is on compression stroke. Because a power stroke only lasts about 120 deg, and the engine (3 cyl) fires a cylinder every 240 degrees, the crankshaft's speed is somewhat irregular. The constant increase and decrease of the crankshaft's speed causes everything that is attached to the crankshaft to mirror the speed increase/decrease. Since the main transmission has two shafts (main shaft and countershaft) and 2 different sets of gears, those gears are in constant mesh but they have clearance, as the speed of the shaft that they are attached to increases, it takes up the slack in the gear it meshes with, and vise versa as the speed decreases--what you are hearing is the slack between them being constantly taken up and then released at a very fast rate. This is normal and if the dealer is asked to investigate and finds nothing abnormal, kubota won't generally pay for "exploratory surgery" as will any other manufacturer if they think nothing is abnormal or defective. AFter all, the limited warranty covers defects in manufacturing, if there is no defect they can't fix anything and thus they can't pay for it. I've been through this, it's particularly loud(er) on the L3301 and L3901 gear drive models, HST models not so much but the gear drive models ARE noisy as heck right around 1000-1200 RPM. Above that, they quiet down. Also the L3301/3901 engines are MUCH quieter than the L2501 is, thus the operator hears it "louder" because the noise isn't covered up by the noisy L2501 engine. Most L2501 owners never hear it either, a few notice it however, but there's really not much that can be done about it aside from increasing the engine speed a little.
What you are hearing is the gears rattling against themselves in the main transmission (H-M-L gear). There is nothing wrong. When you mash the clutch pedal down, the main transmission STOPS, so it can't rattle if the shafts and gears are not turning. The rattling is caused by the engine; 3 cylinder. Every Kubota diesel engine has 4 strokes per cycle, an in the case of a 3 cylinder, it fires one cylinder every 240 degrees of crankshaft rotation. When the fuel is ignited, the crankshaft speed increases slightly, until approximately 90-120 degrees of crankshaft rotation, where the crankshaft tends to level off, then eventually slows down again as another cylinder is on compression stroke. Because a power stroke only lasts about 120 deg, and the engine (3 cyl) fires a cylinder every 240 degrees, the crankshaft's speed is somewhat irregular. The constant increase and decrease of the crankshaft's speed causes everything that is attached to the crankshaft to mirror the speed increase/decrease. Since the main transmission has two shafts (main shaft and countershaft) and 2 different sets of gears, those gears are in constant mesh but they have clearance, as the speed of the shaft that they are attached to increases, it takes up the slack in the gear it meshes with, and vise versa as the speed decreases--what you are hearing is the slack between them being constantly taken up and then released at a very fast rate. This is normal and if the dealer is asked to investigate and finds nothing abnormal, kubota won't generally pay for "exploratory surgery" as will any other manufacturer if they think nothing is abnormal or defective. AFter all, the limited warranty covers defects in manufacturing, if there is no defect they can't fix anything and thus they can't pay for it. I've been through this, it's particularly loud(er) on the L3301 and L3901 gear drive models, HST models not so much but the gear drive models ARE noisy as heck right around 1000-1200 RPM. Above that, they quiet down. Also the L3301/3901 engines are MUCH quieter than the L2501 is, thus the operator hears it "louder" because the noise isn't covered up by the noisy L2501 engine. Most L2501 owners never hear it either, a few notice it however, but there's really not much that can be done about it aside from increasing the engine speed a little.
Loved the in depth explanation. This could be it given this is all accurate, which I have no reason to doubt that it is. I have noticed the the sound difference. This weekend however I remembered this thread and listend again when pushing the clutch. I don't seem to notice the "rattle" or "air puffing" sound as much now as I feel like I did previously. Id still be curious to see what the OP hears from the dealer on it though.
Cars with clutches have a "throw out" bearings. When NOT loaded (clutch not engaged) they sometimes get noisy. When you push in the clutch pedal, the pressure on them makes them stop the noise. You usually always change the bearing when doing a clutch job? You can feel the bumpy bearing when you replace them.
Could that be the noise? Learn to live with it? Not worth bothering with until the clutch causes problems.
??
Mike
Could that be the noise? Learn to live with it? Not worth bothering with until the clutch causes problems.
??
Mike
Hi Chris, welcome to the forum! I have a suggestion, delete this post, which you can do by clicking on "edit", and then start a new thread with a title that includes L3901 in it. That will increase the chances the people that know the most about this model will read it. The L2501 and the L3901 are really different breeds of cat!
My L3301 has done the same thing since new. I checked the PTO cable, but it was not binding, not partially engaged, etc.. I figured it might be the throwout bearings, but I found some other posts suggesting these just have noisy HST pumps and no insulation, which could make sense too. Is your's HST?
Either way, my neighbor bought an L3301 also and it does the same exact thing. I've had it almost 5 years with no change and no negative effects, so I stopped worrying about it. Hopefully that puts your mind at ease a little.
Either way, my neighbor bought an L3301 also and it does the same exact thing. I've had it almost 5 years with no change and no negative effects, so I stopped worrying about it. Hopefully that puts your mind at ease a little.