I took a look at the 2 drive belts. One was very, very loose and it was the original Snapper belt that came on the tractor and the other one was somewhat tight as it should have been, but it was missing chunks of rubber. Also, the hydraulic fluid filter doesn't look like it had been changed in many years. You guys might have figured this out, hopefully.
Make sure you get the correct replacement belts. The first set I bought were regular fractional HP belts that crossed to the Snapper belts. They were too narrow. They looked good but were bottoming out on the pullies. I ended up buying the correct belts from partstree, they were a little expensive but they have lasted for several years now.
Thanks again for the heads up on all of this, gentlemen! Here's a picture of the belt slack......you can't really see in the picture, but it's really loose. You can't really see in the picture, but it was so loose I was almost able to get it up on the edge of the pulley and walk it off.
Also, I just picked up two OEM Snapper belts on ebay.......after the discounts it came to about $20 and some change shipped for both.
Glad you found one of the problems. Please be sure to change that fluid in the trans axle and the filter. You will save a ton of money down the road by not having to rebuild the unit later. Parts are hard to come by.