Noise after coupling change

hi all, new to freelander ownership but been on the forum for a while. had the freelander for a month now 2005 TD4 70k on the clock, loved the car brilliant to drive etc but noticed tight when reversing so decided to change the viscous coupling. got one from a local place to me freelander spares uk fully reconditioned unit. fitted it this afternoon road tested and found a slight whurring noise when doing 30mph.

just wondering if anybody has had this before or any ideas to what it could be, does the couping need to bed in???

much appriciated!!!

did ya change the bearings as well as the vcu? oh and they are all tight reversing while turning. it the way the vcu and 4wd system works on the car

hi, thanks for the fast reply!! yehh the vcu came with everything on there and i made sure they are sat straight on the car.......also matchmarked the prop.
im wondering if one of the bearings is fualty. the noise is from the centre of the car when no power is on i.e overrun.

cheers