Disco 1 Rear diff pinion tight

Folks have fitted a new seal and flange kit to disco 1 but when I tighten the flange retainer bolt (not the nut type) to the 72nm if pretty much locks up and wont spin by hand but will at a push if i put socket on the nut to turn it.
Fitting the halfshafts to see if the flange spins when they are in is also a non starter.
If I back the nut off on teh flange it all becomes looser and will spin.

Do I need to adjust spacers? Ideas please.
Thanks

shims are between the bearings unless you removed a bearing and a shim(shims cant stock to the bearings and come adrift later) it shouldnt need altering either flange mudshield is binding on diff case or the seal or the spacer is missing ,later flanges and all 3 bolt flanges have spacer inbuilt, replacement 4 bolt dont allways