6340 Front Axle

My 6340 is marking the fields quite badly, along with concrete and tarmac. It looks as if the front tyres are grabbing/gripping, especially when turning. I read in the tractor manual that the front axle diff lock should automatically disengage, but am now wondering whether this has failed and that the diff lock is stuck on, hence the mess. The tractor is practically unusable to due the damage it causes on surfaces, not mention the possible further damage to the axle. Any ideas? Many thanks.

Possible causes I would look at, in 4wd, wrong front to rear tyre ratio, differential stuck on. Has your tractor got a button to turn on the diff ? because it turns off by giving the brakes a quick dap, the tractors with a diff pedal might mean it's be stuck partially down. Or is your tractor got air controls? then you want to check there's no leaks.

Thanks for your reply. Im happy that the tyre ratios ok. The front are 11.2 x 24, with 16.9 x 30 on the rear, exactly as specified when new. Theres a diff lock pedal on the floor, near my right heel, but isnt that for the rear wheels only?

What type of axle do You have? New Carraro 20.14 or old Zetor/Stetex?
https://www.stetex.sk/naprava-predna-hnacia-UR1-30km[/]

It appears to be a ZTS.

Actually, it looks like the one in your link above.

Just a thought, but is the 4WD and/or front axle diff lock air assisted? I noticed tonight that the air gauge is at zero and no air is expelled from the tank when the condensate plug is opened. Just behind the tank theres what appears to be a valve with two wires running to it - one green and one brown. The brown one has ripped off.