I have an issue with my 1999 gt 235, 18 hp briggs, 54" deck, 398 hours.I bought it new & it has been a great tractor. Keep in mind I mow my yard that is 2 acres weekly. The rear hub seals are leaking cause the steel washers that John Deere put on these tractors are not hardended therefore the hubs wore thru the stock washers and ate the aluinum top case out on the seal surface. After looking into this , speaking to my john deere dealer the only way to fix the problem is by purchasing a new top case, new axle shaft, hub seals, bearings, hardened washers & swapping my guts into a new top case. Total quoted cost with labor is $ 1100.00. My dilema is its hard for me to justify spending this amount of money ( 20 % of what I paid ) on this 10 year old tractor that I gave $ 4,700.00. I am looking at a new X500 with a 54" deck - total cost out the door is $ 6,200.00. I am 35 years old so I have alot of mowing to do down the road. What would you do if you were me?