i had some baler string wrap a front wheel on my 4500 and cut the seal and started leaking ....i took the hub assembly off and just took that to Deere to replace the seal ..saved a lot of cost...those seals require a lot of work to get to from the inside...point is the drop hub splits in half and just unbolts and that part is easy to transport etcMy front axle on my JD 4700 has been leaking for about 10 years. I tried different weight oils, vented cap etc..... However, nothing worked. I got tired of adding oil, so I finally gave in and took it to the shop. They replaced the seals and some bearings. I thought about doing it myself. However, I get nervous when I see gears and bearings! Hopefully, the gosh darn leak is cured!