Worst part of it is you have to take the oil pan off. Depending on mileage and how bad the rear main seal is I would consider doing the crucifix seals at the same time. Truck has to be jacked up and frame crossmember under oil pan removed. I also drop one side of the tie rod to ease removal. You may want to consider a new water pump and power steering pump gasket and be sure to check your idler pulley bearings while you are at it. I think Oreilly auto parts has a fan wrench you can borrow.

 

So you mean this cross member ?