squealing

Had a question my rk 55 started making a squeel noise that is just the worst on the ears randomly if i use the auto button. I will be driving and whn i let off the accelerator it will continue to squeel. If i touch the pedal either forward or reverse the nosie will stop. The sound is different...

I have a Troy-Bilt Pony riding mower that is only six months old and a squealing noise coming from around the area of the trans-axle is getting worse and worse, almost constant. I can't really tell exactly where it's coming from but I'm pretty sure it's not the kind of squeal a belt would make...