Kuboa L4850 4wd problem

[hugho]

My L4850 with 4K hours has worked flawlessly for many years but while pushing a heavy load of snow and ice with the loader I suddenly heard a clunk clunk noise while in 4wd and eventually noticed that that had a 2wd tractor. Works fine in 2wd. I pulled off the frt driveshaft cover and saw nothing of interest awry. It is a rather small driveshaft spined on both ends inserting into sliding couplings frt and rear. Not sure what to do next. When the 4wd lever is engaged the shaft feels well locked and has slop when disengaged. I am a decent mechanic with a lift and good set of tools but I'm not sure what to look at next. My shop manual shows a profile but no help on troubleshootiong R&R.

 

[merlynr]

Have you searched on Kubota section for possible causes? I sort of remember someone had a bad cv joint on one wheel but don't quote me.

 

[merlynr]

Raise front end off the ground and turn one wheel by hand and other wheel should turn opposite direction. Then hold one wheel and shouldn't be able to turn other one. Not much help but may be able to narrow it down a bit.

 

[hugho]

I took off the driveline shield and the cross member and the noise seemed to be in the ring and pinon area. Drive shaft seemed frozen on the coupling. Kubota tore it down and said all were bad. The mechanic said he worked for JD for 10 yrs before moving to Kubota and said my breakdown was common enough with all the MFG of these small/med TLB's. They have no planetaries like the bigger 4wd tractors and the drive pinon/ring gear is a direct connection to the wheel.