Mr Mower Man wrote:The reason I suspect heat damage is because I wasn't able to get the belt very tight. It squeals a lot every time the electric PTO is activated. I adjusted the spring tension as much as I could when I replaced the belt 3 months ago, but it still wasn't very tight. In my opinion, the spring is too weak, weaker than other springs that do the same thing on other brands of mowers. I'm thinking tighter belt tension would improve this situation, or else maybe Swisher belts are junk and I need to try an aftermarket belt from Oregon or Gates or something.
Any insight from you all?
The above was your first mistake.. generally if your instinct is telling you something ain't right.. then something ain't right.. I'd have dug a bit deeper - check belt mountings? Idler arm brackets (that the spring tensions) have been known to develop "detents" - wear spots that stop it from having a full range of movement (not to mention rust can do the same thing.. if you spot telltale rust oxides around pivot points, do yourself a favor and disassemble and clean, repair and/or relubricate) , springs can be weak they can also be hooked into wrong holes (sometimes the most obvious hookup is not always the right one) , pulleys can be worn enough that the belt fits too deeply into the V groove and becomes loose (Many customers call it a "stretched" belt, but most belts do NOT stretch (they can't its the kevlar cording that determines their length, if that breaks, you got a broken belt even if the belt looks whole) But belts DO wear the sides and sit deeper in grooves, making them "seem to" stretch even if they look fine) Almost never see dry rot on belts unless they have been sitting unused for many years - so your other instinct would be correct and it is heat damage.. but the cause of the damage is most likely gonna come back on you, its gotta be found and fixed , or further belts (I assume you checked the belt to verify it actually IS OEM... Believe it or not, but even factory authorized distributors are well known for substituting aftermarket in place of factory OEM (comes from the same manufacturer, same production line, same stuff, just doesnt get to go through the OEM's quality control checks)
So, I would say your first order of business is to diagnose why the belt seemed loose.. Bear in mind any mis-alignment of the deck mounting in relation to the mower frame (or even engine mounting bolts, has engine every been out, and maybe bolted in to the wrong place?.. things like that) - can cause the deck to sit in such a way that belt will be loose (all mount points checked? deck checked for level? all pulleys checked for correct sizing? service history? new PTO clutch that might have a wrong pulley, or an updated pulley needing a 5/8 belt where a 1/2 used to be? Bent spindles, bent deck (making spindles orientation change) ? many many things to check..
How poor are they who have not patience. What wound did ever heal, but by degrees? - Iago (Othello Act II, Scene 3)