Originally Posted by
Quantra
Are you sure it's the nut which is rubbing? If you have a mark in that area on the drive shaft it could be the ST21 servo track rod that is rubbing at full lock. It's worth a look as it's quite tight and tricky getting it right so it doesn't hit the top deck or main shaft.
I am positive it was the nut. I forgot I had ordered the floating servo mount, so when I put it on I checked the nut. It had just backed off.