Low front axle or hub oil issue---Kubota experiment

sixdogs · Aug 30, 2016

Everyone knows about the problem when you change the oil in the front hubs or axle on a Kubota. It looks full, smells full and is full. Come back 8 hours later on the meter and you have to add a lot more oil, regardless if gear or hydraulic. As well, it's a common issue with new Kubotas in that you have to add axle/hub oil a few tractor hours after new.

Anyway, I was changing the front axle on hub oil on a new-to-me Kubota M6800 and I ran out of gear oil before I was done. I hate it when that happens. So I just left the fill caps off overnight and got some in the morning. Surprise, surprise, I got all the gear oil in on the first try. What I think happened is that the air burped itself out of what I put in after I left the fill caps off overnight. Since I changed my L and B gear oil last fall, I have nothing to compare with. Is this the solution or merely an isolated situation to cause further aggravation on this simple issue? Maybe it's just on the M's? Maybe just on some M's?

Maybe others could try this if they change their axle or hub oil this fall and report back. We might be onto something.

nikerret · Aug 30, 2016

My front axles were full the first time I checked them and the last time and every time in bewteen. I've never found it low or added any. Perhaps, my dealer has a method to get it right? Or, I'm just lucky, in this regard.

Here's a link to my dealer, if you want to call them and run your theory by them:
Lawn & Garden Equipment Dealer Whitewater KS Near Derby, Maize, Hutch, El Dorado & Newton | Mowers, Tractors, Balers & Backhoe Loaders

repete · Aug 31, 2016

My 2550 has two vent plugs at the wheel ends. I have to remove them when changing the grease in the front axle otherwise the grease does not find its level in the bevel gear case and only with time will it.

Open the bleeders, fill the front axle, let it site for a few minutes and then top off. I actually installed a replacement bevel gear case years ago and I had to drill and tap it for a vent plug as it had the boss in the casting but not plug installed.