Going against the grain here on some of the replies, I always use the Clutch when shifting a 2-Speed Rear. Not only is it recommended by the factory, it will shift smoother with using the Clutch. And I drove trucks with 2-Speed Rears for over 23 years, lol. But all of mine were Electric Shifts.
HF Farms, I read your first post on your shifting procedure and everything sounded fine to me. Although I have no experience with Vacuum, in my opinion it sounds like you losing something and not getting full Vacuum to the Rear.
Just to add a little extra, when Split Shifting Hi to Lo, shift the trans first, then hit the button down just before letting the Clutch back out.
Right on the Transmission, 4-Speeds, back then anyway, are not Synchronized 1st.
Last edited by C10 - C90 Bill; 11/24/2019 6:24 AM.