This is the same transmission drive train in popular Case 580 line. Anyway my machine is a 2000 WB140-2 Komatsu. My question / concern regards 4wd. When 4WD is engaged and I am traveling across my property there is a violent lurching or uneven drive in my machine. You can see it looking at the front tires, they turn smoothly then seem to stop for a fraction of a second then continue in a cyclical fashion, i.e. maybe once per wheel revolution. The tires are in good condition. There is no apparent loss of power or function. The problem is isolated to the front drive train and goes away when 4wd is disengaged. It may be worse when the front bucket is not loaded and is worse at higher speeds. It is in both first and second gears. I don't use higher gears but I assume it is present in all gears. It may be worse in forward than in reverse but there may be less force on the front axel in reverse. Anyway my concern is with cascading damage to the drive train due to the violence of the lurching. I have had the machine for 2 years but I am now using it more frequently. The problem has been there from the beginning. It feels similar to if one where to pop a clutch. The transmission has a torque converter but of course there are internal clutches, so that is one thought 4wd is slipping out of engagement and then re-engaging. The other thought is that there is a problem in one or both of the final drive planetary gear sets in the front wheel. E.g. stripped teeth causing the gears to skip a couple teeth then slam into the next one that catches. What does the forum think? I don't want the problem to propagate back up into the transmissions. It recently changed the transmission fluid and it was surprisingly clean. I could take the covers off the final drives and change their fluid.
Are the tires the correct size and is there uneven wear. I had the problems you describe with my Case 580 and it actually turned out to be a bad front axle U-joint. It was constantly slipping like one of the tires were on ice.
The tires are matched and in good condition. I don't think they are the wrong size. Maybe it is a u-joint but I don't think when I looked the u-joints seemed to have a problem. It' s not slipping. More skipping. Sounds and feels like heavy metal slamming into heavy metal. Like there is excessive backlash in a final drive.
That is what I was thinking as i was reading! As the joint goes thru its planes, it will accel and decel, A bad joint could make this much worse.
Maybe
What's the best diagnostic for a bad u-joint?
I think it would feel sloppy if you tried to turn the driveshaft back and forth. Maybe lifting the front wheels off the ground and twisting them back and forth would reveal a bad u-joint??
Not only is tyre size important but also tyre air pressure. To much or to little changes the radius making the system do weird things.
Just put the axle up in the air and turn wheels to full stop one way and turn wheel, looking at the u-joint and front axle.
I'm assuming that tractor has planetary gear sets in the hubs. Something broken in one of those might cause your symptoms.