Probally too tight.I alwyas tighten them tight then back off till just loose.Then just snug them down.Ive done them for over 40 years but once you do them a few times you get the feel for it.I dont like tight bearings.As long as the rotor dosent move they are good.Some drag will be felt.Try loosening them.Till loose and turn the rotor.Then start snugging till you fell a bit of drag spinning the rotor.Then install the cotter key.I did them at work for over 30 years and never had a bearing failure.Rocky