On our 450J, about 3 months back the blocked air filter light came on. so I bought a new outside element (as the inside one looked to be clean and in fine shape) and replaced it, I work in very dusty conditions and so take it out and clean it every 20 hours or so. About a week ago the blocked transmission filter light came on, so I bought a new one and replaced that. however now both of those warning lights periodically come on and go off, doesn't matter how clean the air filter is or how well I put it on the light still comes on, and I made sure that the transmission oil filter was on nice and tight and it isn't cross threaded (it has what seems to be a super slow leak, after ~12 hours of use it hasn't leaked enough to form a drip but enough to make the outside of the filter half covered in oil) i'm afraid to do it up any tighter as I already did it hand tight then another 1/3 of a turn with a large wrench. My question is why on earth wont these lights stay out? Also should I just tighten the oil filter more?
With the air filter you could have a bad filter restriction switch or some moisture in the connector. The trans light however is something I would be concerned about. If you still have the old filter I would cut it open and see if there is anything in the filter. Although it could have a bad sender too as I have seen them stick. I am assuming your temp is above freezing though? The reason I say that is when the oil is too thick it will make the filter go into bypass and set the light. Are you using deere transmission filters? Wondering if it was aftermarket if they were too fine of a micron it could make it go into bypass. As for the leak, you probably tore the oring or moved it from the grove slightly. I usually lube the oring and then spin it on hand tight without a tool, never had one come off or leak doing that.
It seems to have stopped leaking, we are well above freezing here and I did use a Deere filter. It just flicks on now and then for a couple of minutes