L4310 three point jumpy

[YesDeere]

First off this is not mine but a good friends. Was his grandfathers til he passed away last year.

A little background. It had some major work done a year and a half a ago. All I know is that the connecting rod for the three point lift was bent and the top
Plate cracked. All was replaced and it was fine. All this work was done by someone else. But now it has been dropped in my friends lap.

Currently we have it inside shop to service it and replace bushings and pins on steering that had not seen much grease. Searched on here and seems like the steering slop is a common problem on this model. Anyway to the new problem.

The three point is constantly going up and down. It can be temporarily stopped by adjusting the rate knob under seat. I was just wondering if anyone has seen this or can give me some insight. Before we start tearing apart. And possibly going in the wrong direction. Sorry for long winded post. Any help would be appreciated.

 

[Grandad4]

Sorry to hear of your friend's problem with that L4310. I've owned a similar model for about 9 years now, happily with no problems.

Re. steering slop being a common problem on these models. Maybe I'm uninformed (won't be the first time!), but this is the first I've heard these models had any tendency toward excessive wear on the front axle. I understand some of the older model L's had a different front axle design that was prone to bearing failures (I think from the 1980's), but the design was changed well before this particular model was introduced (that 4310 would probably be from '98 to '03). There are some guys with a lot of knowledge about Kubota equipment here who can explain more (or correct me, as the case may be).

The irregular 3pt is also atypical for this model. I would have to think it either relates back to the repair somehow or it's somewhere in the hydraulic circuit. Does the tractor have a loader on it? Is it an HST model? If so, are there any problems with the operation of either of those? A common problem with loader tractors is loose or dirty quick connects or other fittings being the source of intermittent or irregular hydraulic issues like you describe. Before going inside, I'd want to be sure everything external was clean and tight.