My damper rod holding tool nicked the damper rod about 6mm below the (cone-shaped) lock nut. This won't be a problem unless the seal will contact this part of the damper rod when the suspension is bottomed--if it does my seal will be ruined:(
Does anyone know how close the seal comes to the end of the damper rod? I'm hoping that its not less than 6mm!
I can't be the first to have this problem...the spring force pushes the damper rod into the holding tool fairly hard!
I have a groove all the way around mine in the same place. The holding tool didn't hold it and allowed it to spin. I don't think the damper compresses that far in operation. I haven't had any problems with it yet...but I did quit using that holding tool.
The rod goes all the way up until the lock nut bottoms against the bottom of the tube. It may still miss the seal. To be sure, you could remove any rough edge from the rods nick so it doesn't mark the seal. If you sand a smooth depression where the nick is, you may just loose a small amount of oil each time the seal passes this area. If it would add up to oil loss and air in the cylinder is unknown.
This is how I compress my showa fork to disassembly.