I know to release the hydros before towing a mower, but a friend of mine didn't. His mower died on his lawn and he couldn't get it running again so he towed it to his garage with his truck without releasing the hydros. He said it pulled fine without skidding. It's a pretty big yard so it could have been for 100s of feet. He has a Bob-Cat Predator Pro with the Hydro-Gear pump and Parker wheel motor combo. I showed him where the releases are and told him not to do that again and that he could damage the transmission. He wants to know what damage he may have done. He got it running and he says it seems fine. Should he change the fluid and filter after having towed it or anything? Just how bad is it for the this style transmission?