Freehub won't rotate freely

[Shut Up Legs]

I have a Shimano FH-T780 freehub (in the Deore XT series), and found that the freehub was recently seizing, and it gradually got worse. Today, I removed the freehub body from a spare hub (same model), which was not that easy, because without the hub attached to a wheel you need to find another way to get the necessary leverage to undo the bolt inside the freehub.
I then put this freehub body onto my rear freehub, carefully tightened the nuts and locknut so there was a fraction of a millimetre of sideways movement. Then I put the wheel back on the bike, and took care not to tighten the QR skewer too much. Unfortunately, this freehub body moves even less freely than the one I removed! When I spin the wheel forward, then let go of the pedals, the pedals start rotating also.
Any ideas, CC experts? I've replaced a freehub body before and it went well, but this time I'm having no such luck.

Regards,

--- Victor.

 

[Levo-Lon]

Id think there dry..or maybe worn out..
there is a grease port on the free hub,iirc from my old ones ..small hole at the base where the largest cog sits.or it could be the other end...you will see it , looks like a small drill hole into the hub

service the wheel bearings while your at it as the bearings may be worn but that wont make the free hub stick..

 

[Shut Up Legs]

Id think there dry..or maybe worn out..
there is a grease port on the free hub,iirc from my old ones ..small hole at the base where the largest cog sits.or it could be the other end...you will see it , looks like a small drill hole into the hub

service the wheel bearings while your at it as the bearings may be worn but that wont make the free hub stick..

Thanks, I'll see if I can find the grease port. It's odd that both the existing one (fairly new) and the one I took off the unused new hub are both doing this, though. Unless it's just a bad luck coincidence.

 

[Levo-Lon]

Is it the free hub?
Could be the cones are over right as both are causing the pedals to turn..
Free hub stiff with the wheel out..would be the free hub...so check the wheel bearings and cone tension if the free hub is ok with the wheel out..

 

[Shut Up Legs]

Is it the free hub?
Could be the cones are over right as both are causing the pedals to turn..
Free hub stiff with the wheel out..would be the free hub...so check the wheel bearings and cone tension if the free hub is ok with the wheel out..

Thanks again for the reply. As I said in my original post, I've replaced freehub bodies before, and always take care to check the bearings, cone tension, locknut, etc.
I can't find any grease port, by the way.