BX24 dropped drive shaft now I have a vibration.

[rnbrn21]

So yesterday I was moving some dirt and there was a terrible noise and as I was backing up my front drive shaft was on the ground. Upon inspection it looks like I lost the pin that holds the universal joint on the the input spline of the front axle. I went to the Kubota dealer this morning and got a new pin. It all went back together easily but now I have a vibration when driving in 4WD. In 2WD it is smooth. I inspected everything and it all looks good. If I spin the front wheels I feel the gears in the front end and that seems to be the vibration I'm feeling but I can't see how dropping the drive shaft would have a effect on those gears. The input shaft of the front end seems good with no play. I tightened the pivot bolt which was very loose (something I have never done before). The splines on the universal joint got a little damaged when it came off, but only at the very out edge. I've ordered a new universal joint, but the joint itself is nice and smooth. Any idea on what my vibration might be. I'm fairly sure it wasn't there before.

 

[zoltanthegypsy]

U joint phasing? Don't know if that's even possible on a BX. It's not at the pinned joint but may be at the mid spline. Dunno...

Z.

 

[airbiscuit]

 

[rnbrn21]

Great video, but I've done nothing to change any of the angles involved.

 

[zoltanthegypsy]

Great video, but I've done nothing to change any of the angles involved.

Apologies if you're already on top of this, but in case we're not quite on the same page yet: it isn't just about angles. If the drive shaft was all the way out and on the ground, any chance the mid spline was reinserted so the two u joints were no longer correctly phased. If they aren't, you'll likely get vibration.

Z.

 

[airbiscuit]

It's not about the angles, it is about the phasing (relationship of the u-joints to one another) Did the driveshaft come apart?

 

[rnbrn21]

Now I understand what you are getting at. I did not think I about the "phasing". Thank you for being persistent in my ignorance. I'll have to investigate this further because I did not take that into account when I put it back together.

 

[rnbrn21]

So I realized, I never replied with my findings. I checked the phasing of the u-joints of the drive shaft and found after having it apart and back together a couple of times that it was only off by one spline from being in phase. I corrected that and there is still a vibration. The vibration that I'm feeling is fine and not course, a higher frequency. When I had the drive shaft off, I felt it just by spinning the front wheels. I have no doubt I'm feeling the gears in the front axle. The question is why now. So I never drive my tractor in 2WD. So I'm wondering if the little that I did while the drive shaft was out was so smooth that when I got the drive shaft back in, feeling of the front axle gears was noticeable. When I drive in 2WD no vibration. The question to the forum is, can you tell a noticeable difference when you drive your BX tractors in 2WD and 4WD.

 

[Henro]

Everything still turns when in 2WD. Just no power is transmitted through the drive shaft to the front axle.

Maybe what you are sensing now was there all the time, and you never noticed it.

I think my BX feels the same whether in 4WD Or 2WD.

What is the condition of your tires? If the fronts are worn a lot more than the rears this would change the effective rolling diameter ratio, and might show up as stress in the driveline. Low front tire pressure could also contribute to the same effect.

Just a couple out-of-the-box thoughts....

 

[310-510]

After more than 2500 hours on my BX24D, it has dropped the front shaft several time. The pin in the shaft at the front axle breaks. I suspect from the splines not lube and binding when going over rough terrain. Regularly lubing the splines in dusty/dirty conditions solved my front drive shaft issue for the past 3 years(or so).

I did replace the u-joints about 5 years ago, checked the shaft phase, and it still had the vibration.

Yes, mine stays in 4wd unless transporting on hard ground and it does have a vibration when in 4wd vs 2wd.