B3X tight in reverse
 

B3, has about 83 hours total time. changed ratio from 2.0 to 2.20, new upper gearset, new pinion bearings. Set up driven gear with tool-had to reshim to get proper depth. Checked lash-.019 on both fwd and reverse, new races so both fwd and reverse are now.014 lash. Driven gears, - and + ticks directly above one another. Fully assembled, filled with lube and noticed that when turning the input shaft, I have a very tight spot in reverse, but loose enough that i can turn it over by hand. I marked the universal to see where it was and it affects about 20 degrees about every 1.5 revolutions. Forward and neutral are butter smooth. Lash feels good even in the tight area. I have now taken it completely apart 4x and cant find the tight spot on the bearings, races, thrust bearings.
https://cimg6.ibsrv.net/gimg/www.off...76a478dcd1.jpg
https://cimg7.ibsrv.net/gimg/www.off...8b8c6be353.jpg
https://cimg8.ibsrv.net/gimg/www.off...5e7968426c.jpg
https://cimg9.ibsrv.net/gimg/www.off...7b87198bf9.jpg
What could this be?

Pull out the shift shaft and cam, put the top cap back on and try it and see how that feels( with the cone ingaged in the top gear)

Ok, drained it down-took out the cam...
 

As the title says, I pulled the shift shift and cam, put it in reverse, torqued the top cover and no tight spot. Does this make it better, worse, adjustable or don't even worry?

It’s most likely the shift cam rubbing on the high spot of the lower driven gear bump ring.

Once it’s running and it goes through the normal shift process where the bump ring ( via the shift cam)drives the cone up into the gear cup and the three components ( shift shaft, gear floor and shift cone) screw themselves together and become tight,
that contact will most likely be gone….I’d run it on the hose, put in in reverse and listen for any noise clicking noise in reverse