I have a 1996 1845C. I just purchased it. The right side has a power loss going forward and whines when I push forward all the way on the right control. New fluids and filter. I am suspecting the tandem pump. I suppose I could switch the lines between drive motors and see if the problem switches sides. Any ideas?
Does it whine in revers on that side?
Its likely the pump getting old and tired. As you mentioned, swap the lines to the motors to verify. I have seen people rebuild their own pumps, and sometimes they will just need a new valve plate, or they lap the old one. The service manual has a fairly good rebuild procedure in it. Just make sure to install the charge pump the proper way. Also be careful with the pins in the block.