Reporting back in after almost 2 seasons of cutting 1.3 acres with the GT-262. Still doing a great job. I run right through the thick grass now and it handles it fine. I cut to 2.5" in fall and spring, and 3" in summer when the grass is slower growing. The combination of fixing my engine oil leak, OEM Belts, new blades (gators), and regular tune-ups, cleaning and greasing the deck all have kept the deck/tractor running very well. Treat em well and they treat you well. This year I went over our second Garden tractor (1972 Allis Chalmers 718 and it's also doing a great job) The AC718 had deck issues also. I went with OEM belts, new blades (stock Simplicity which are same as AC), cleaned and greased the deck and still had deck issues. I finally found the deck idler pulley to be seized. I put some oi in it and it started working fine. I did get a new idler pulley and installed it and that tractor works great too. Lubrication was desperately needed in the 72 AC. It had a blown motor early in it's life and sat for decades. Careful lubrication, and a replacement Kohler 16hp motor (which is a great motor) has that tractor working great too. Now my wife and I can each hop on a GT and get the lawn done in nearly half the time. I can't stress enough the value of doing the maintenance and lubrication at least as often as recommended on these work horses. I'm sure most of you know that but I add this for anyone just starting out on these machines. The OEM belts are well worth their cost based on my experience early on with Non OEM belt failures and issues. I you do buy a used GT make sure you go over it ASAP. Both of ours looked nice and seemed to run OK when we bought them, but there were certain signs of neglect evident as I went along. No-OEM belts might be a hint that a seller was cutting corners. Everything should spin freely on the deck off the tractor. When the deck was off the tractor is when I found the issues, slipping deck belt, frozen idler pulley.
Anyway, thanks for all the great suggestions for things to check, 2 years running well now on 2 older tractors. Reb