Hydraulic system

I would say,that the Motion Drive Belt,has stretched to the point,that it is slipping on the pulleys. Over time all belts stretch or break. There is no adjustment,that can be made,once stretched,its time for a new belt. Look in your Owner's Manual,to see,a picture and directions of how to remove and replace a motion drive belt. If there isn't a picture of the drive belt in your manual,then look under the left foot rest. There you will find a decal,showing the correct method to install the belt over the pulleys. This is going to be a long belt,it runs from the Transaxle to the motor's upper pulley assembly. You can,it will be hard to do,remove and replace the drive belt with the mower deck attached. First,try lowering the mower deck,to the lowest position. This will give some room,to get to the motion belt,you will have to remove the mower belt,to get to the motion belt. I find it is easier to just remove the mower deck entirely. Doing this,give you ample room to work on the motion belt. The mower belt,can be purchased from Sears Parts Direct. Give them the tractor's Model Number and the Belt Part #,if you have the number,they will look it up anyway,if not. I gave more information,than you asked for. I hope this will help you. Sincerely,Brad Locke DTD. 12/04/15