quick help please vs live axle , axle swap

[bwian]

swapping axle in vs, on tightening securing 4 bolts axle ceases to turn. Handbrake is off and it is in neutral. Axle is out of vs, same size visually but live axle it came from had a whine. Oil seal went in the one I am replacing. Should I just get the seals and replace, have i erred on installing replacement or would replacement be kaput seeing as it was from a diff that whined.

[bwian]

update: Seems the axle is slightly longer by 2-3 mm, put old one back and axle turns. Ah well, back to drawing board: sigh!...