B3030 4WD issues

[Colin313237]

Kubota B3030 HSTC - 4WD locks up after a few feet, reverse releases it


I’m looking for some advice before I start tearing into the tractor.


Kubota B3030 HSTC with approximately 600 hours.


Symptoms:

• In 4WD, the tractor will move a few feet and then there is a distinct clunk/bang and it locks up.
• Once it locks, it feels like the tractor has hit something solid.
• The engine continues running normally and does not bog down.
• Reversing will often release the bind and allow it to move again.
• In 2WD, the tractor drives much better, but I occasionally still feel like something wants to catch under load.
• The lockup feels like it is coming from the front of the tractor.
• Front axle oil level is full.
• Steering is normal.
• Loader operation is normal.
• If I keep the speed extremely slow and apply power very gently, I can sometimes continue moving in both 2WD and 4WD. The problem becomes much more noticeable as load or speed increases.

Before this became severe, I noticed some increased vibration/shaking for a few days.


The symptom that really stands out is that 4WD makes the problem dramatically worse. It will often lock within about 5 feet of travel in 4WD. In 2WD it is much less severe.


I’ve been reading about:

• Front driveshaft U-joints
• Front driveshaft splines
• Splined couplers
• 4WD engagement collar/fork issues
• Front differential input components

Has anyone experienced these exact symptoms on a B3030?


Would you inspect the front driveshaft splines/coupler and U-joints first, or does this sound more like a 4WD engagement mechanism issue?


Any advice is appreciated.

 

[North Idaho Wolfman]

Pull the propeller shaft and lift thee front end one wheel at a time and see what you feel or hear when you spin the wheels.
Use the WSM for more front end info.

 

[Colin313237]

Pull the propeller shaft and lift thee front end one wheel at a time and see what you feel or hear when you spin the wheels.
Use the WSM for more front end info.

So i lifted it up and the wheels turn easy an no off putting noises. i didnt pull the prop yet. But when i turn the prop by hand i can feel it get caught and lock. Then after a little giggle i can get it to go again. In 4wd it will not rotate by hand. But i suspect thats normal?