B2410 Kubota - Rear end howl

[Benza]

Hey there folks, long time lurker, first time poster.

Having a bit of a headache with a B2410HSD 4WD that a friend wanted me to look into. He brought it to me saying that it would howl in high, full throttle, going down the road. Won't make the noise in low, or anything below full forward.

Has 1200 hours on it, and he uses it primarily to drive down the road.

Sure enough, drove it around and the howl is coming from under the floorpan/seat. Checked hydraulic fluid, and he had it way overfilled by about 2 quarts. Drained the excess fluid off, but no difference. Got ahold of Kubota and they pushed me in the direction of changing all the bearings in the transmission and differential housings, since overfilling can cause cavitation in the bearings.

Tore down the back end of the tractor and tore apart the tranny, differential housing; Everything back there.

So we took care of the bearings, in addition to the hi speed gears inside the tranny. We didn't touch the pinion gears in the differential. Got everything back together and it's still making the noise, only in high gear, full throttle, full forward, but not as loud. It typically only makes a slight whine now going down a small incline - Not when any load is on the axles.

Any ideas? I swear it sounds just like the gear whine my old Farmall B used to have going down the road. I'm thinking it may be coming from the rear axle gears. Kubota, when asked again, said to change the bearings in the rear axle housings; Regardless, I came here for another opinion before I tear the axle housings off again.

 

[100 td]

Just remember, you are asking for an opinion, here's mine.

I don't quite get this, you say in another thread "I work at a Kubota dealership as a technician" yet in this thread you say
"Got ahold of Kubota and they pushed me in the direction of changing all the bearings in the transmission and differential housings, since overfilling can cause cavitation in the bearings."

So you "tore apart the tranny, differential housing; Everything back there."
and "we took care of the bearings, in addition to the hi speed gears inside the tranny."
When that didn't work you say
"Kubota, when asked again, said to change the bearings in the rear axle housings"

Maybe you can square that up and answer the following, what was the actual condition of the bearings when you inspected them? What fault did they have and what was the real cause of the fault? What was the condition of the high speed gears and why did you change them?
Whilst I do really know that there are many and varied causes for bearing degradation, and I have used bearing monitoring analysis equipment, I haven't come across any that have been degraded because they are running under too much oil, but I'm prepared to be schooled?

I would expect the hydraulic fluid level may vary by up to a couple of quarts depending if the 3pt and FEL is raised and bucket curled etc.

Now you are ready to "tear the axle housings off again" after you've just changed the bearings in them, because there is "a slight whine now going down a small incline"
I think you are "like a bull at a gate" and need to step back and re-evaluate and get some help from some experienced mechanics before you waste more of your time and your friends money.
But that's just my personal opinion, so don't take it too harshly.

 

[100 td]

And just to clarify, I'm not a tractor mechanic, so it's just an opinion............YMMV

 

[Benza]

Just remember, you are asking for an opinion, here's mine.

I don't quite get this, you say in another thread "I work at a Kubota dealership as a technician" yet in this thread you say
"Got ahold of Kubota and they pushed me in the direction of changing all the bearings in the transmission and differential housings, since overfilling can cause cavitation in the bearings."

So you "tore apart the tranny, differential housing; Everything back there."
and "we took care of the bearings, in addition to the hi speed gears inside the tranny."
When that didn't work you say
"Kubota, when asked again, said to change the bearings in the rear axle housings"

Maybe you can square that up and answer the following, what was the actual condition of the bearings when you inspected them? What fault did they have and what was the real cause of the fault? What was the condition of the high speed gears and why did you change them?
Whilst I do really know that there are many and varied causes for bearing degradation, and I have used bearing monitoring analysis equipment, I haven't come across any that have been degraded because they are running under too much oil, but I'm prepared to be schooled?

I would expect the hydraulic fluid level may vary by up to a couple of quarts depending if the 3pt and FEL is raised and bucket curled etc.

Now you are ready to "tear the axle housings off again" after you've just changed the bearings in them, because there is "a slight whine now going down a small incline"
I think you are "like a bull at a gate" and need to step back and re-evaluate and get some help from some experienced mechanics before you waste more of your time and your friends money.
But that's just my personal opinion, so don't take it too harshly.

Sure, I can describe what we've done so far a little more clearly.

No loader on unit. Bearings we took out and replaced all looked OK - One or two had some audible noise to them when spun. He wanted them changed anyways.

-Got unit from friend, drove it around and tried to figure what was causing the noise. Was overfilled, so removed excess fluid.
-Before digging into it, contacted Kubota at work to see what they thought. Explained the noise, when it occurred, and the excess fluid. Kubota said that overfilling can cause cavitation of bearings, and that we should replace the bearings in the transmission and differential housing.
-We separated both axle cases from the differential housing, HST from the tranny housing, and tranny housing from differential housing. We replaced all bearings within the transmission housing and differential housing. Because he used high speed more than anything, we replaced both high speed gears and an idler gear that looked worn. (Compared them to the new gears, and they were definitely worn; more mushroomed than they should have been, wear marks on the inside of the teeth.)
-We did not replace the differential pinion gears, nor anything in either axle housing, because both looked fine when we pulled them off. Pinion gear backlash was within spec.
-Reassembled everything together, test drove. Still making 'gear whine' noise, albeit a lot softer now.
-Talked more with Kubota. They're glad we made 'progress', now insist we change the axle housing bearings in addition to checking backlash on pinion gears again.

So that's where I stand. And no worries, opinions are what I'm looking for! I'm still learning about the innards of these transmissions and differentials, so criticism is good.

 

[100 td]

Great, well I've just re-read and noticed that I read your bearing change out as "diff/axle", not diff without axle, so my mistake there. However you do say that you looked at the axle housings and didn't change the bearings because both looked fine. By all means look again, but remember that these are relatively low speed bearings, so for them to whine something needs to be wrong.
Did you check spiral bevel pinion and spiral bevel gear backlash as well as differential pinion and differential side backlash?
Just as a reference for techs who chime in, what oil are you using?
From tractordata the tranny takes 13.2 quarts, I can't see 2 quarts over causing any bearing problems, but I'm prepared to learn.
It's not a HST whine being transmitted by any chance, my B21 makes a fair bit of noise, I just buy better earmuffs!

 

[whitetiger]

Hey there folks, long time lurker, first time poster.

Having a bit of a headache with a B2410HSD 4WD that a friend wanted me to look into. He brought it to me saying that it would howl in high, full throttle, going down the road. Won't make the noise in low, or anything below full forward.

Has 1200 hours on it, and he uses it primarily to drive down the road.

Sure enough, drove it around and the howl is coming from under the floorpan/seat. Checked hydraulic fluid, and he had it way overfilled by about 2 quarts. Drained the excess fluid off, but no difference. Got ahold of Kubota and they pushed me in the direction of changing all the bearings in the transmission and differential housings, since overfilling can cause cavitation in the bearings.



Tore down the back end of the tractor and tore apart the tranny, differential housing; Everything back there.

So we took care of the bearings, in addition to the hi speed gears inside the tranny. We didn't touch the pinion gears in the differential. Got everything back together and it's still making the noise, only in high gear, full throttle, full forward, but not as loud. It typically only makes a slight whine now going down a small incline - Not when any load is on the axles.

Any ideas? I swear it sounds just like the gear whine my old Farmall B used to have going down the road. I'm thinking it may be coming from the rear axle gears. Kubota, when asked again, said to change the bearings in the rear axle housings; Regardless, I came here for another opinion before I tear the axle housings off again.

Did you have the front axle engaged or disengaged when driving down the road?