MTD Huskee 50" Rear Belt Issues
Hi. So I've been having trouble with my MTD lawn tractor. I've tried looking at it myself, but I can't figure it out. I've taken this mower to TWO local shops and the first one is a repair place/parts dealer. He flat out tells me "Well, I don't want to look at it. You're always buying parts here so you can probably just fix it yourself." Second place I called, explained what it was doing, guy asks me if I've even worked on mowers before, so I answer truthfully, "yeah, engine work, but not stuff like this". "Oh, we're busy for the next 2 weeks. You'll figure it out, it'd be cheaper for you anyway. Bye.". Ugh. So, I'm hoping that with your help, we can get this mower running again. 
Oh, I should mention the model number is 14AP849P131.
The problem is the rear drive belt keeps coming off. Three things will make it do this.
1. Letting off the brake too fast
2. Putting it in High Range (Low, Neutral and Reverse don't seem to cause this as much)
3. Hitting any bump in the yard
When I first got this tractor two months ago it didn't have a rear drive belt. I put a new one on (genuine MTD) and that's when the trouble began. The guy from the first shop did say that the front belt was not the right belt, though. Some other things were the idler pulley bracket was very loose due to a missing nut. Fixed that, it's still coming off. Also the idler pulley does seem to make a little noise, but turns without any resistance. The variable speed pulley is really rusty, also. Something I discovered today is that if you (engine off) hit the brake, the idler pulley takes tension off the rear belt and the variable speed pulley moves. Belt does not come off. Yet, if you move the idler pulley back with your hand the belt comes off and gets wrapped under the transmission pulley. My current theory is that when running anytime the idler pulley moves, the variable speed pulley is supposed to also move to compensate for the lack of tension from the idler? But, since it is rusty, sometimes it sticks when hitting the brake, and only the idler moves, causing a sudden lose of tension and the belt comes off? I have noticed that when it jumps off that there is a hesitation like the pulley is "grabbing" the belt instead of letting the belt turn with it. I'm also wondering if the transmission pulley itself is worn down. Should the belt be deep in the pulley or should the belt stick out a little past the transmission pulley?
I figure if I replace both belts, idler bracket, idler pulley, transmission pulley, and the variable speed pulley, that should fix it. But, all that would be expensive. I don't want to replace anymore than necessary. I hope all this makes sense. Thanks in advance!
Edit/Update: I got the variable pulley off. It spins on the shaft without noise. The center pulley moves up and down, but will sometimes when it reaches either the top or bottom pulley, it freezes up a bit. Secondly, the little bracket that the brake pedal attaches to, the one with the spring is rusted in place. Added some photos.
Oh, I should mention the model number is 14AP849P131.
The problem is the rear drive belt keeps coming off. Three things will make it do this.
1. Letting off the brake too fast
2. Putting it in High Range (Low, Neutral and Reverse don't seem to cause this as much)
3. Hitting any bump in the yard
When I first got this tractor two months ago it didn't have a rear drive belt. I put a new one on (genuine MTD) and that's when the trouble began. The guy from the first shop did say that the front belt was not the right belt, though. Some other things were the idler pulley bracket was very loose due to a missing nut. Fixed that, it's still coming off. Also the idler pulley does seem to make a little noise, but turns without any resistance. The variable speed pulley is really rusty, also. Something I discovered today is that if you (engine off) hit the brake, the idler pulley takes tension off the rear belt and the variable speed pulley moves. Belt does not come off. Yet, if you move the idler pulley back with your hand the belt comes off and gets wrapped under the transmission pulley. My current theory is that when running anytime the idler pulley moves, the variable speed pulley is supposed to also move to compensate for the lack of tension from the idler? But, since it is rusty, sometimes it sticks when hitting the brake, and only the idler moves, causing a sudden lose of tension and the belt comes off? I have noticed that when it jumps off that there is a hesitation like the pulley is "grabbing" the belt instead of letting the belt turn with it. I'm also wondering if the transmission pulley itself is worn down. Should the belt be deep in the pulley or should the belt stick out a little past the transmission pulley?
I figure if I replace both belts, idler bracket, idler pulley, transmission pulley, and the variable speed pulley, that should fix it. But, all that would be expensive. I don't want to replace anymore than necessary. I hope all this makes sense. Thanks in advance!
Edit/Update: I got the variable pulley off. It spins on the shaft without noise. The center pulley moves up and down, but will sometimes when it reaches either the top or bottom pulley, it freezes up a bit. Secondly, the little bracket that the brake pedal attaches to, the one with the spring is rusted in place. Added some photos.
