Kubota L39 GST Grinding/chattering noise when in motion?

[DivineL39]

I am a proud new owner of an L39. Only has about 550 Hrs on it. My question is about a noise I hear when I am traveling. IT doesn't happen all the time, it happens whether or not the 4wd is engaged, and no matter what gear i am in, though It almost always is there at higher range gear operation. It is a sound of grinding or chattering gears. Doesnt sound right. Maybe it's normal. I have searched quite a bit and haven't found anyone talking about this with a GST. Could any Kubota GST owners chime in and let me know if they hear noises like this when driving their tractors.
Im not certain, But I don't think the fluid and filters have ever been changed. It is on my list of things to do. Kinda disappointing to be looking at a several hundred dollar service just after buying the unit.
Any comments are appreciated.

 

[caballero59]

I am a proud new owner of an L39. Only has about 550 Hrs on it. My question is about a noise I hear when I am traveling. IT doesn't happen all the time, it happens whether or not the 4wd is engaged, and no matter what gear i am in, though It almost always is there at higher range gear operation. It is a sound of grinding or chattering gears. Doesnt sound right. Maybe it's normal. I have searched quite a bit and haven't found anyone talking about this with a GST. Could any Kubota GST owners chime in and let me know if they hear noises like this when driving their tractors.
Im not certain, But I don't think the fluid and filters have ever been changed. It is on my list of things to do. Kinda disappointing to be looking at a several hundred dollar service just after buying the unit.
Any comments are appreciated.

These sounds are not normal for the L39.

 

[DivineL39]

These sounds are not normal for the L39.

Thank you for responding to my question.
How should I proceed?

 

[sandyc]

Make sure your not in four wheel drive

 

[DivineL39]

Make sure your not in four wheel drive

Thanks for your point.
I did specify in the original post that "it doesn't matter whether not its in 4 wheel drive.".
But your reply makes me wonder. Is this a normal sound in 4WD? If so, Is it possible Im not successfully disengaging the 4WD.
Thanks Again

 

[rScotty]

Thanks for your point.
I did specify in the original post that "it doesn't matter whether not its in 4 wheel drive.".
But your reply makes me wonder. Is this a normal sound in 4WD? If so, Is it possible Im not successfully disengaging the 4WD.
Thanks Again

I've never heard of one making any different transmission sound in 4WD.
We could use some more information. How does it drive? Have you checked the level of the trans/hydraulic fluid? How does it look or smell?

Most power shift or glide shift transmissions use sets of multiplate clutches inside the transmission to engage & disengage gears. Those are hydraulically actuated internal clutch packs, and yes, you would get those chattering & gear slipping symptoms if the hydraulic fluid is low, or the hydraulic filters are clogged up.

You might also get those sounds if the wrong hydraulic fluid was used and has made those clutch plates slip and grab. When you check the hydraulic fluid on the dip stick, make sure it is clear or amber and not burnt or especially not looking milky or stingy.

Since the fluid and filters could cause the problems you are hearing, and since you suspect the fluid was never changed, then why not change fluid & filters? Yes, it's costly on these Kubota TLBs. The good news is it doesn't need to be changed often, but it definitely needs to be done after break-in because that's when the hydraulic filters get clogged with break-in particles. Those are suction filters. It is very common for clogging suction filters to restrict the flow of fluid and cause the hydraulics that work the powershift/glideshift to work poorly.
rScotty

 

[DivineL39]

I've never heard of one making any different transmission sound in 4WD.
We could use some more information. How does it drive? Have you checked the level of the trans/hydraulic fluid? How does it look or smell?

Most power shift or glide shift transmissions use sets of multiplate clutches inside the transmission to engage & disengage gears. Those are hydraulically actuated internal clutch packs, and yes, you would get those chattering & gear slipping symptoms if the hydraulic fluid is low, or the hydraulic filters are clogged up.

You might also get those sounds if the wrong hydraulic fluid was used and has made those clutch plates slip and grab. When you check the hydraulic fluid on the dip stick, make sure it is clear or amber and not burnt or especially not looking milky or stingy.

Since the fluid and filters could cause the problems you are hearing, and since you suspect the fluid was never changed, then why not change fluid & filters? Yes, it's costly on these Kubota TLBs. The good news is it doesn't need to be changed often, but it definitely needs to be done after break-in because that's when the hydraulic filters get clogged with break-in particles. Those are suction filters. It is very common for clogging suction filters to restrict the flow of fluid and cause the hydraulics that work the powershift/glideshift to work poorly.
rScotty

I have ordered the filters and fluid. Will do that as soon as I get them. The fluid looks ok, It was 2.5 gallons low when I got it though. It looks clear on the dip stick, but amber when i see a drip out of a quick disconnect. no funny smells either.
I haven't noticed anything odd about the way it drives or shifts. I will post an update when I change the fluid and filters.

 

[mike69440]

There is a lot of gear chatter on my L39, Always has been noisy since new but with 2500 hard hours, I'm sure it is louder now than it was when new. The gear chatter & wine is mixed in with the engine and hydraulic pump noise. The noise is not grinding like you would hear with a bad bearing. Some days I worry about it a bit, most times I figure it is part of all those gears going round & round.
Just use 80W-90 synthetic gear oil in place of hydraulic oil in the front axle. My L39 is a bit noisier in 4WD than rear drive, by just a bit.
If the gear noise overpowers the engine noise, then to me that may not be normal, so you ought to have it checked out, but quiet, these tractors are not.
As the tractor seems to work fine, just change all fluids with premium stuff and go do some work.

 

[DivineL39]

There is a lot of gear chatter on my L39, Always has been noisy since new but with 2500 hard hours, I'm sure it is louder now than it was when new. The gear chatter & wine is mixed in with the engine and hydraulic pump noise. The noise is not grinding like you would hear with a bad bearing. Some days I worry about it a bit, most times I figure it is part of all those gears going round & round.
Just use 80W-90 synthetic gear oil in place of hydraulic oil in the front axle. My L39 is a bit noisier in 4WD than rear drive, by just a bit.
If the gear noise overpowers the engine noise, then to me that may not be normal, so you ought to have it checked out, but quiet, these tractors are not.
As the tractor seems to work fine, just change all fluids with premium stuff and go do some work.

Well that is reassuring. Sounds like you are hearing the same thing as me. I bet it takes me 10 to 15 years to get to 2500 hrs. Honestly you are the first person in a lot of internet searches and questions that has heard this noise. Wonder why no one else has it? Maybe people do and just don't pay it any attention. I am a worry-a-holic.
Any ways, Thank you. You just might be the reason I decide to keep this tractor instead of selling and finding a hydrostat. I just got the thumb and grapple bucket installed, would be a shame to sell her down the river. Hey, have you found any trick to creep when using your backhoe? like just move a few feet without switching the seat around. without disabling the seat switch.

 

[DivineL39]

I Changed the fluid and filters today. Pricey yes, But it was well worth it. I used it some, Not a lot, its raining now.
I did not hear my gear chatter that I had. I can still hear the tranny when driving at faster speeds, but barely, Sounds more like normal. Best thing is right off the bat I could see it shifted smoother and much quicker. Also seemed to make my sticky bucket control a little smoother. It really made a big difference.
I was surprised when I did the fluid change. The sample on the dip stick looks like clean oil. But the stuff that came out of the ole girl was dark and nasty. Not milky, just dirty. And I was correct, It was the first time Its been done, The filters were the same color as the subframe, and had assembly shavings on the magnets.
I should have done this before I started a thread. But Maybe someone else out there will find this info when they have the same question. Lord knows I couldn't find a single person that had ever heard such a noise in a GST tractor till this thread. And for low a experience guy like me, Its amazing the difference new fluid and filters can make.
Next up
Front Axle oil change.