Could it be the coupler form engine to hydraulic pump. Is there a way to get the tires to free wheel to move the skid steer with hydraulic pump not working?
Yes. The pump drive is also called the coupler. This has been a common problem. A new design is out, I think it has two clamp bolts and is slightly longer. They would slip out of the splines and cause them to strip off the teeth. Very early models had release screws on the side of the pump near the middle. All have been removed since and no towing option is available. CAT says to just drag it on the tires for short distances only. A medium sized fork lift will pick it up, it weighs around 7000 pounds.