I had an issue with the Toybox binding on the h55f output shaft as they slid together. I examined the splines with a hand lens and I'm sure they where clean and deburred. I spent a long time with a micrometer and discovered that the diameter of the output shaft was was about .008" larger at the base then where it was cut.
I marked the output shaft with a sharpie to see where it was binding, which was about 1/2 down the shaft. I filed the splines with a diamond file, cleaned, marked and test fitted the pieces. I repeated this process 4 or 5 times until the Toybox stopped binding.
You might want to consider dry fitting the bits before you apply sealant.
I saw your posts about the binding issue. They were very helpful, and part of the reason I started this thread. I am going to dry fit everything, go slow and make sure it all works before sealing anything up.
This is a great thing to do always we have run into this once but the other two we did, did not have this problem. A small 3M scotch brite pad on a small angle grinder will normally take care of this for you and polish the surface at the same time.
Cam