i am new to boating and recently got one with a 120hp mercruiser with sterndrive. I need to replace the impeller on the sterndrive so I drained the oil, put the shifter in forward and removed the sterndrive from the boat. All 6 bolts have been removed to split the caseing, I can lift the gear box up approx. 1/2" then it comes to a dead stop. It appears to be hitting on the lip of the shift linkage on the outter side of the casing. any suggestions to to getting this fella apart would be great. I do not want to bust anything so I figured id try the experts.