I have a Simplicity Broadmoor 16 hydro that seems to have a weak hydrostatic drive. Is there anything that can be done to add a little life to the trans? I can still mow the lawn. But, it labors and whines anytime I try to go up an incline. I was told by a local dealer that it would cost $1200 just for the parts...that they don't repair the hydrostatic drives because it's too labor intensive. They just replace the hydrostatic drive. Ideas or suggestions?