4905 gmc transmission

[perkinstrades]

I need to remove my 4 speed tranny from my gmc 4905 so the rear main seal can be replaced.  I have seen a fixture for attaching to the top of the tranny, but don't have one, I can make one but need to know where the thing attaches to the top of tranny for a good balance.  Am assuming that the fixture I.ve seen accomplishes that.  Can someone provide a diagram or discription of the fixture, attachment points or any other info helpful to me about this endeavor.  I'm all for a smooth experience.  thanks