I have a 2003 JD310g that blows oil out the parking brake vent in 3rd and 4th gear the transmission was ran hot have been running for several years and adding fluid was told by john deere mechanic that has since retired that it was a seal leak that could be fixed without removing transmission any ideas or suggestions New john deere mechanic wants to sell a rebuilt transmission
Welcome to HEF Ron . I believe the vent you are referring to is in the center rear axle housing behind the park brake housing. See screenshot below. If the rear axle housing is actually overfilling with transmission oil it would be due to leaking park brake piston seals and or the differential lock piston seals. The park brake can be resealed without removing the rear axle from the machine so you might as well reseal it first . Monitor the rear axle oil level (at the fill plug) over 8-40 hours of use and see it it continues to rise. If so the diff lock will need to be resealed. https://partscatalog.deere.com/jdrc/sidebyside/equipment/64103/referrer/navigation/pgId/370101 .
thanks for the info finally got back on this project, seals leaking on brake piston out of curiosity does the differential lock use pressure to release or engage
Diff lock requires pressure to engage