Yeah, 86082 is for the ones on the center shaft for the transmission, in the front at least. The rear is either a larger steel one piece hex/output cup 86322, or a two piece that uses a cup like 86082 and a piece that fits it for the brake disks to ride on, 85044. Or, if you have the dual...
What brakes do you have on it? Is that an old school 21 chassis (pre-X lower cg chassis plates)?
You will hear some gear noise when it rolls... but that sound to me is either
the brakes binding a tiny bit
the older steel brake disks binding on the hex hub due to a bit of wear/slop on the...
They should fit... just check to make sure your brake disk isn't rubbing the clutch bell. I had that when I geared mine down for larger tires. I had a steel spur and didn't want to buy another spur just to run the tires, so I put 2mm aluminum washers between the engine and the mount to raise it...