Kubota L4400 Front Differential Problem

Bobsoldit · Jan 5, 2020

I have an L 4400 and the FWD stopped working. I exposed the front driveshaft, inspected the couplings and everything looked great. I engaged the FWD and the output shaft from the transmission stop turning. Correct me if I知 wrong but I think I致e narrowed the problem down to the front differential. I can turn the two front tires independently or together, same direction or opposite with no foul noise or binding. The input shaft to the front differential spins freely by hand but does not turn when the tires are manipulated. I致e never explored the front axle of a tractor and I知 a little intimidated. Should I drop the axle and start at the input shaft or leave the axle in the tractor and start one of the hubs? If one of the hubs was making noise the answer would be easy. Thanks in advance for any advice

Rebeldad1 · Jan 5, 2020

If the front tires are on the ground and the rear wheels are engauged, 4wd engauged and the front driveshaft turning I would look at the coupling splines or pinion gear. Cant tell but guessing the differential has spyder gears ... if they were blown that could cause it as well.
Try draining the front gear oil first and see what comes out. put a strong magnet in the oil as well. While the oil is out you can stick a screwdriver or coat hanger up to the ring gear and see if its turning as it should.

Billrog · Jan 5, 2020

I've had a few apart not as bad as it appears to work on. I don't think there's need to remove the front dif.

Bobsoldit · Jan 6, 2020

Thanks for the replies and encouragement. Just thought it would be easier to work on sitting on the bench in front of me rather than me on my back. I only had time to remove it and get it cleaned up yesterday. Tonight I値l pull the shaft and take a peek. It looks like I値l have to sacrifice the seal to get to the retaining nut.

Bobsoldit · Jan 6, 2020

So no luck on pulling the pinion shaft. I didn't have a socket deep enough. So I pulled both ends off and slid the axles out, I could see in there well enough to see the pinion gear was smooth and the ring gear is shot as well. I can't wrap my head around how the ring and pinion come out? Has anyone done this that can offer some advice? Is it pressed is? How does the ring gear come out? It's nothing like a car differential.

Billrog · Jan 6, 2020

Had mine out 2 years ago all in pieces but can't remember any details about the dismantle.

I had every piece out, the whole thing was destroyed 100 hrs. after the first service which I did by the book. Dealer told be the manual was wrong it took 6.? lts. not 5 us quarts. Kioti gave me a complete new dif. free even though it was off warranty. The they told me to use trans hydraulic rather than gear lube. I just changed the oil in it a wk or 2 ago 1,000 hrs. later and there was no sign of metal not even fine metal when I checked the oil with an earth magnet.
If you can post a pick it may be helpful in getting some help there's others here with far more experience than me.