Hello...today I was changing the pinion seal on my 1977 ford f150 4x4 with the dana 44 axle and after removing the yoke there was a some type of seal or dust cover that needed to be pryed out and removed before you can get at the pinion seal....this part was not removable without destroying it...and the local parts stores do not show this part in any of there systems. So my question is do you need this part and if yes were can I find one ?