While changing the water pump I noticed that in one spot the upper shift rod has rusted to 1/2 it's origional diameter. I'm told the power head has to be removed to replace the shaft and was quoted $2500 to $3000 by a local mechanic. I'm considering doing the job myself and would appreciate any advice. Can the 11 bolts that hold down the power head be removed without snapping? If so, how? Is there any way to reinforce the rusted area on the shaft (1/4") making replacement unecessary?