*update*
After replacing the hydros, it did ok. As I used the truck in town and got everything up to operating temp, it would be hard to hit reverse. I also noticed that downshifting, it would "studder" when the clutch was released. Now the engine is bad, so I will replace the clutch when the engine comes out. I have a LUK clutch to go back in it. Hopefully this will fix the issue.

 

I had similar symptoms on a SB OFE clutch with 80k on it and thought hydraulics at first. Hard to get into gear when stopped. Adjusted up master cyl throw and was a little better. Had to float the shifts. Another hundred miles and it was worse.
Thought it was pilot or throwout sticking maybe keeping it from disengaging all the way, but then it started slipping. Another couple hundo and it would slip easier.
Turned out clutch lining was just wore out.
Weird part was the clutch went from hero to zero in a couple hundred miles.
Had Just pulled a long trip with big truck camper on it, plenty of full throttle, uphill 6th gear pulls with a 150? Hp tune without issue followed by a day of empty around town driving then instantly hard to shift and get in gear.

 

I'm really old fashioned. I don't think either a needle or roller bearing is the hot set up for a pilot bearing. The next time I pull the gear box, Iwill make a pilot bearing out of Silicon Aluminum Bronze, grease it and forget it. Remember these motors go slow and the pilot bearing is only working when the clutch is depressed and a speed difference exists between the crank and the pilot shaft. When that happens, the speed difference is less than 1,000 rpm. Who needs a rolling element bearing? Bushing have been used for many, many years very successfully.

 

Personally I would stick with a sealed roller bearing. The problem with greased bronze or needle bearings is over time the grease attracts dust and other foreign materials which will increase resistance between the flywheel and input shaft when the clutch is depressed.

This happened to me with shifting issues a while back. The needle bearing was still good but the grease was like coal tar and made it very difficult to get into gear when cold. The NV-5600 isn't a light weight tranny and is difficult to work with without the proper equipment.

 

When I did my clutch I felt the same and I used a brass bushing and I have a friend who used a bushing made of Teflon and He has over 60,000 miles on it I have about the same on my brass one.
Jim O