Did I Break 4WD on my BX?

[bluedunn]

Hi-

Over the weekend I was out with my tractor, in the woods, doing some grapple work. I had my Kubota BX1860 in 4wd and everything seemed to be fine.

As I was backing up, I noticed the front, left tire start to spin quite fast (faster than the other tires) and the axle seemed to be making a popping or clicking sound (hard to say as I had my hearing protection in). My wife, who was out with me, also noticed this. I turned around, still in 4wd and the front left tire did the same thing - it actually tore up some of the ground. I didn't go more than 10' and stopped and took it out of 4wd. I immediately took it back to the shed and parked it and checked the front axle fluid, which seemed normal.

Yesterday I used the loader to raise the front end off of the ground, turn the tractor off, and then proceeded to put the transmission into 'rabbit'. After doing this I rotated each tire, which freely spun independent of each other. I then put the 4wd lever into 4wd and tried the same 'test' with the same result; both tires were spinning independently of each other. This makes me feel like something is wrong and I now have a 2wd tractor. Am I doing this test incorrectly? Is there something else I should do to validate that the 4wd drive isn't hosed? What should I be looking at to diagnose? I don't really relish the thought of pulling the front axle apart :-(

If the 4wd is broken am I harming anything by continuing to use the tractor without it - leaving it in the disengaged position? Honestly, I don't know if I can afford to fix this right now, but anticipate needing to use the tractor.

Thanks for any help!

 

[Henro]

When you say turning independent of each other, do you mean turning in opposite directions? This sounds normal.

Not sure about the sounds you we’re hearing.

The more specific info you give will help those smarter than me ( lots of them here) give you great guidance.

 

[bluedunn]

When you say turning independent of each other, do you mean turning in opposite directions? This sounds normal.

Not sure about the sounds you we’re hearing.

The more specific info you give will help those smarter than me ( lots of them here) give you great guidance.

Sorry about that - what I meant that they were not turning in opposite directions, but instead I'd turn one of the wheels by hand and the other did not move. I did this on both sides, with the front end up in the air, and the result was the same. One wheel spins, but the other does not move.

I can't really describe the sound other than, with hearing protection in, it sounds like a clicking or popping sound.

Thanks!

 

[Henro]

Sorry about that - what I meant that they were not turning in opposite directions, but instead I'd turn one of the wheels by hand and the other did not move. I did this on both sides, with the front end up in the air, and the result was the same. One wheel spins, but the other does not move.

I can't really describe the sound other than, with hearing protection in, it sounds like a clicking or popping sound.

Thanks!

I think this will be important info for those who can help you.

 

[hodge]

If 4WD was engaged, then the drive shaft could not spin. In that case, the opposite tire should have rotated the opposite direction. Because it didn't, something is broken in your front axle, or the drive shaft is broken. Or, it could have broken inside of the transmission, so turning one tire could rotate the driveshaft. The next step would be to pull the cover on the shaft and see if it will rotate by hand while 4WD is engaged. If it doesn't, and the shaft is otherwise intact and still connected to the pinion shaft, then it's inside the axle.

 

[woodman55]

It's not sounding good. With the front axle in the air, and the tractor in 4x4 and low range. One wheel should turn in the opposite director of the other. I would not continue to use the tractor even in 2x4.

I would check and see if the front drive shaft is still intact. Redo your test and see if the front shaft turns where it comes out of the front axle. Sadly I am thinking it will not be turning.

If you feel comfortable doing this. Drain the oil out of the front axle into a clean container and see what it looks like and if any small pieces come out. Run a magnet through it and see if it picks up any metal. It could also have gray or silver streaks in it ( a sign of metal).

I am thinking you have a internal failure, and will need to talk to your dealer or a good mechanic.

 

[Fordtech86]

Redo your test and see if the front shaft turns where it comes out of the front axle. Sadly I am thinking it will not be turning.

if only spinning one tire at time, the driveshaft won’t spin, the axles will just spin around the spider gears. Would need to spin both front tires at the same time in the same direction(in 2wd if the rear tires are on the ground) to get the carrier to spin to turn the driveshaft. (Edit: if something is broken this won’t work either, trying to spin both front tires at the same time and see if there is a little more resistance to turning though may still help with diagnosing)

From the OPs description of the left front spinning faster then normal, I would guess something on the right side is broke and binding the axle shaft going into the carrier. Would cause the opposite side to spin faster.

 

[armylifer]

I had a similar experience with my BX1860 a few years ago. What happened with mine was I broke a pin that holds the drive shaft to the transmission. In my case though the drive shaft actually fell down on top of the MMM deck. I got a new pin and pinned the propeller (drive) shaft back in place. From your description though it sounds like you could possibly have a broken part (hopefully just a u joint) on the front of the propeller (drive) shaft.

Start by removing the propeller shaft cover and inspecting the u joint. Then try turning the wheels while in 4wd with the transmission in neutral, and see if the propeller shaft rotates as you are turning the front wheels forward and back. listen for any unusual noises as you do this. Check the front and the rear of the propeller shaft for looseness. That should be a good start and hopefully you will find the broken part.

 

[Fordtech86]

If OP noticed one front tire spinning I think it’s safe to say the front driveshaft (propeller shaft) is “ok”. A u joint wouldn’t cause a single side of the differential to over run.

 

[armylifer]

If OP noticed one front tire spinning I think it’s safe to say the front driveshaft (propeller shaft) is “ok”. A u joint wouldn’t cause a single side of the differential to over run.

I did not take his description as an over speed effect. I took it as one wheel spinning and the other one static. I could be wrong though.

 

[bluedunn]

I did not take his description as an over speed effect. I took it as one wheel spinning and the other one static. I could be wrong though.

Thanks all. I’m getting that sinking feeling based on the responses.

In answer to this point, my wife said that the left front was spinning faster than the other wheels… which doesn’t sound good. I was very focused on looking at the front left, while my wife had a better vantage point to look at everything.

 

[armylifer]

Thanks all. I’m getting that sinking feeling based on the responses.

In answer to this point, my wife said that the left front was spinning faster than the other wheels… which doesn’t sound good. I was very focused on looking at the front left, while my wife had a better vantage point to look at everything.

The left front wheel being smaller than the rear wheels would appear to be spinning faster than the larger rear wheels. The visual effect of a smaller wheel spinning could make someone who does not know any better think that it is actually spinning faster than the rear wheels.

 

[bluedunn]

The left front wheel being smaller than the rear wheels would appear to be spinning faster than the larger rear wheels. The visual effect of a smaller wheel spinning could make someone who does not know any better think that it is actually spinning faster than the rear wheels.

Good point and she was standing to my left, and vantage point was such that she was looking at me/the tractor from the side.

 

[Fordtech86]

I could be wrong though.

me too!

As I was backing up, I noticed the front, left tire start to spin quite fast (faster than the other tires) and the axle seemed to be making a popping or clicking sound

would spin faster if the right tire was in a bind and couldn’t spin, open differentials will spin the side with least resistance.

I turned around, still in 4wd and the front left tire did the same thing - it actually tore up some of the ground.

shouldn’t do this (well it can, but sounds like it’s not what OP has experienced before and seems to be consistent with left front)

I may read too far into these it’s just habit from my day job

 

[armylifer]

Good point and she was standing to my left, and vantage point was such that she was looking at me/the tractor from the side.

There is one other thing that I am thinking. That is the noise you are hearing could also be the axle pivot bolt could be loose and making noise. Check the torque on the axle pivot bolt. You may not have any real problem with the 4wd. That is my thought anyway.

 

[bluedunn]

There is one other thing that I am thinking. That is the noise you are hearing could also be the axle pivot bolt could be loose and making noise. Check the torque on the axle pivot bolt. You may not have any real problem with the 4wd. That is my thought anyway.

Thanks - I have a place to start looking, which is helpful. Fingers crossed it’s easy-ish to diagnose and fix!

 

[Russell King]

You may want to put all 4 wheels up off the ground with the axles on jack stands and operate it in 2 wheel and 4 wheel drive to see what it does

But let someone else confirm that this is okay and would provide useful information before you do it. Be safe and use low engine speed and stay away from the rotating parts

 

[DustyRusty]

A lot depends on the previous maintenance. How many hours on the machine and has it ever been worked hard? Is a regular maintenance schedule followed, and is it running UDT or gear oil?

 

[bluedunn]

A lot depends on the previous maintenance. How many hours on the machine and has it ever been worked hard? Is a regular maintenance schedule followed, and is it running UDT or gear oil?

Good points all.

The tractor has about 400 hours on it. I can’t say I work it hard, but I do what I consider normal tractor stuff. At the time this occurred I was using my grapple to move a brush pile. Other than that, it’s mainly used for mowing in the summ and plowing in the winter. I rarely use 4wd but the ground in the woods was slick.

Yes, I follow regular maintenance. I’m meticulous about that. I run gear oil in the front axle, not UDT.

 

[#40Fan]

With the tractor in 4wd, raise one of the front wheels off the ground. Give that tire a spin. If something is wrong, I bet you'll be able to hear it.