Ragan 5" siezed

At least, I think that's it's name!
Anyway, when I am operating it in auto-traverse, it runs happily and then the spindle suddenly siezes. I've disconnected the drive from the side-gear
train to the quick-change gear box on the front, and the lead screw/traverse happily turns by hand. When the spindle is connected to just the idler, it runs OK. Could it have anything to do with the locking nut for the spindle-head? How do I take off the top of the housing around the spindle, to see where it's siezing? I undid the top two (8"?) Alen-Key bolts, but it wouldn't budge. Where can I get a manual for it?
Thanks for your interest.
Jmc.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.