Another issue I have is the belt that turns the blades has been popping off when I start the Pto sometimes. I have to start the pto with the deck high and then slowly move the deck down to number 3 for it not to pop off. Any suggestions anyone?
First off, check your spindle bearings. They should be tight when you try to move them side-to-side. Any play necessitates new bearings. Same goes for the idler pulleys on the deck. Bad bearings anywhere here will cause a belt to pop.
But I don't think that's your problem. Read on:
You've got the old-style 46", 3-blade deck on that tractor. How many belt tensioner arms are on that deck? The early system used one long, bent steel tensioner arm, with a pulley on top and a single spring to keep the belt tight. If you have the single-arm deck, the tensioner arm will wear out at the bushing and twist to the side, causing the belt to jump off over the top of the idler pulley. Replace a worn arm and bushing at the same time, and you should be good to go. I like to install a heavy fender washer under the deck, where the idler arm bolt goes through the deck pan, to prevent the arm from bending down again over time.
The newer-style deck looks the same on the outside, but it uses two tensioner arms and pulleys to keep the belt tight. On this style deck, the arms don't wear as badly, but they will rust in place and get stuck where they attach to the deck pan. Disassemble everything, clean the rust out with a wire wheel, be sure both arms move freely, straighten anything which has bent, and reassemble. Problem solved.
As shop manager at a Cub Cadet dealer, I've seen and fixed a lot of idler arm failures on that model. Its a pain to deal with, but it could be worse.