# Front Differential on Kubota 135x



## Goat08 (Dec 6, 2021)

a few days ago we put a reman engine in the 135x kubota went relatively simple except for having to tear virtually half the tractor apart. Long story short we reinstalled the front end under the tractor drove it around the shop a few times good as new we thought. Went to drive the tractor home got about 5 miles down the road and the front end locked up. Lifted the front end with loader tires spin freely but output shaft going to tranny will not budge. Talked to a local hobby mechanic said there is a mechanism that will lock the front end in case of a low oil in differential. Has anyone heard of this?????? Or have an expertise on larger kubota's?????


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## SidecarFlip (Mar 25, 2021)

Not that I know of. You need to consult a real authorized Kubota dealer, not a 'hobby mechanic'.


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## BigT (Sep 15, 2014)

Good Morning jgotham, welcome to the forum.

Was the tractor in 4WD while traveling down the road? Not recommended practice. 

You have probably already dropped the driveshaft and see which end is froze up. Which end is froze up?


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## Goat08 (Dec 6, 2021)

BigT said:


> Good Morning jgotham, welcome to the forum.
> 
> Was the tractor in 4WD while traveling down the road? Not recommended practice.
> 
> You have probably already dropped the driveshaft and see which end is froze up. Which end is froze up?


Thanks BigT ! No just puttering down the road just above idle because if the reman engine was in 2wd. And yes I pulled the shaft to make sure it wasn't in the tranny. Can say it was a real bear to get off the road and onto a trailer to get back to the shop.


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## SidecarFlip (Mar 25, 2021)

Every M series and above Kubota that I'm familiar with uses a splined coupler on the front propellor shaft that is located near the front differential. Per chance did you strip it? Easy to replace and costs about 50 bucks at your local dealer..

I never run mine is FWA on dry pavement. Only use FWA when necessary for added traction.


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## SidecarFlip (Mar 25, 2021)

I see you answered. Maybe it was a failure in the front differential. How many hours on the unit and was the front gearcase full of lubricant? Never heard of one locking up unless the pinion or ring gear was destroyed. I have over 6000 hours on one of mine, 2500 on the other and never had issue one with either the motor or the driveline. Curious as to why you replaced the motor. VTE engines are usually bullet proof if maintained properly. 10K hours plus before any major issues appear so long as they are maintained properly.


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## Goat08 (Dec 6, 2021)

SidecarFlip said:


> Every M series and above Kubota that I'm familiar with uses a splined coupler on the front propellor shaft that is located near the front differential. Per chance did you strip it? Easy to replace and costs about 50 bucks at your local dealer..
> 
> I never run mine is FWA on dry pavement. Only use FWA when necessary for added traction.


SidecarFlip I never run on pavement in 4wd! Pulled the coupler to make sure it wasn't the trans seems the input shaft is locked but if i left the front end with loader tires spin freely but in opposite directions. 4500 hrs and it rolled main bearing. Front differential has 2 hydraulic lines that feed front end just wheeled it out of the way to replace motor


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## SidecarFlip (Mar 25, 2021)

Which is exactly what they are supposed to do when the front differential is unlocked. On my M's the front differential mechanically locks with a pedal in the cab. I'm kind of wondering if the front flexible cable that engages the front differential from locked to unlocked (I presume you can lock in yours like I can lock in mine, is out of adjustment. The adjustment length is called out in the Workshop Manual and applies to all of the M series tractors. If you don't have a hard copy of the WSM, you can download a copy at www.kubotabooks.com The WSM applies to basically all M series tractors from the same ones to the large ones. Mechanically, they are all very similar. Still curious as to why you had to install a reman engine. Did you have a mechanical failure due to lack of maintenance or just a component failure internally. Mine both run like tops and they have at least the one does, a gob of hours on them

Never had an issue with the front wheel assist except the splined coupler wearing out and the front drive getting noisy but replacement of that is pretty simple, pull the securing screws, slide the tube and remove it with the roll pin and replace it. Been my only issue so far.

I wasn't about to pay 300 bucks for a hard copy when there was one available in PDF form. I have an excellent relationship with my dealer and I can access his library of manuals anytime I want to drive up there. Far as maintenance goes, I do all mine except items like valve adjustments, I have them do that.

Like I said, the WSM calls out the correct actuation clearance plus it details all the front end components.

Hope that helps.


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## SidecarFlip (Mar 25, 2021)

The 2 lines are for the steering ram. What kind of oil do you run and how often do you change it? I do an oil analysis on mine, every change btw and I use Rotella T6 5-40 and always Kubota filters, in fact Kubota filters everywhere. The front differential lock cable (on mine at least) is under the frame in the front.

Personally, I would never allow anyone but my dealer do anything mechanical in nature to either of mine. Don't want or need some 'shadetree mechanic' fiddling with either. Both were expensive (bought new and slightly used) and I depend on them as I farm with them. Here you go... One cab, one open station


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## Goat08 (Dec 6, 2021)

SidecarFlip said:


> The 2 lines are for the steering ram. What kind of oil do you run and how often do you change it? I do an oil analysis on mine, every change btw and I use Rotella T6 5-40 and always Kubota filters, in fact Kubota filters everywhere. The front differential lock cable (on mine at least) is under the frame in the front.
> 
> Personally, I would never allow anyone but my dealer do anything mechanical in nature to either of mine. Don't want or need some 'shadetree mechanic' fiddling with either. Both were expensive (bought new and slightly used) and I depend on them as I farm with them. Here you go... One cab, one open station


Nope the larger series Kubota's are a bit different by the looks there are 2 hoses that go to the steering as well as 2 lines that go into the front differential housing from the rear of the tractor. These lines pump hydraulic oil into the front differential (From what it looks like) and then both outside front hubs are filled with gear oil like normal.


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## SidecarFlip (Mar 25, 2021)

...and so is the center section or should be. 2 of them are the hyrdostatic steering and I would assume the other 2 are the front diff lock up. Mine is mechanical. I think I prefer that. Kubota likes to complicate stuff. I take it your front diff lock is via a switch or lever in the cab, whereas mine is via a pedal on the floor. Kind of like sticking the heating and ac under the seat instead of under the roof. Much easier to access on top versus underneath the seat.

I would not like the center section to share the fluid from the gearbox at all. I run 85-140 GL4 gear oil in my front diffs, not fluid. Never have either. My outboards are sealed from the center section and fill independently from the center section.

At this point I''m lost. You might want to consult a nearby dealer. I'd say it's WSM time in the least.


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## Fedup (Feb 25, 2014)

jgotham said:


> a few days ago we put a reman engine in the 135x kubota went relatively simple except for having to tear virtually half the tractor apart. Long story short we reinstalled the front end under the tractor drove it around the shop a few times good as new we thought. Went to drive the tractor home got about 5 miles down the road and the front end locked up. Lifted the front end with loader tires spin freely but output shaft going to tranny will not budge. Talked to a local hobby mechanic said there is a mechanism that will lock the front end in case of a low oil in differential. Has anyone heard of this?????? Or have an expertise on larger kubota's?????


Just what are hoping to find here? Do you need help diagnosing your problem, help with correcting it, or just looking for information?? Looks like you're not having much luck with any of that so far.


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## FredM (Nov 18, 2015)

Goat08 said:


> a few days ago we put a reman engine in the 135x kubota went relatively simple except for having to tear virtually half the tractor apart. Long story short we reinstalled the front end under the tractor drove it around the shop a few times good as new we thought. Went to drive the tractor home got about 5 miles down the road and the front end locked up. Lifted the front end with loader tires spin freely but output shaft going to tranny will not budge. Talked to a local hobby mechanic said there is a mechanism that will lock the front end in case of a low oil in differential. Has anyone heard of this?????? Or have an expertise on larger kubota's?????


 Have you checked the oil level in the front differential?, I wouldn't be surprised to hear that the front input shaft has seized bearings from lack of oil or the crown and pinion has melted from lack of oil.

It is no trouble to spin a wheel with these off of the ground and the reason one wheel will rotate one way and the other is because the planetaries are rotating around the sun gears in the diff, have another person try and rotate the opposite front wheel the same way that you are rotating and bet you can't because of the seizure in the drive line.

There is no low oil lock mechanism in the front diff, only a seizure from lack of oil.


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## SidecarFlip (Mar 25, 2021)

I'd have to ask if the front differential was leaking anywhere prior to this incident and if you ever checked it for contamination or oil level? Really not much to fail up there except the bearings and the gear sets them selves. I feel (may be wrong) that the most neglected part of any tractor is the starting battery followed by the front wheel drive assembly (if you have FWA) followed by the air filter.

Whatever it is, sounds like you have another teardown issue on your hands.

Kubota's have a reputation for leaking gear oil at the circular seal between the upper and lower halves of the outer axle kingpin castings. Had one leaking and replaced it, not a huge job, easy enough that I did it versus my dealer.


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