Scruffy,
I have the same lathe was in sad shape when I aquired it. The weight is right in the 1500 lb range depending how it is equipped. I am still learning the machine.
Here is what I know, the people at Clausing are helpful and can supply many of the parts. I was given a PDF manual via e-mail no charge. I managed to track down a parts list from the Yahoo Clausing group.
Mine as equipped from the factory has a 3 phase 5 HP motor. Hydraulic controlled variable speed drive (some of these have been a source of problems for many but relatively easy to fix), 3 speed ranges. Do not adjust the speed controller unless the machine is running. Mine is equipped with the D1-4 chuck mount.
At a minimum I would check/replace headstock and apron oils.
If you have questions feel free to ask away, my knowledge base does not run very deep, but there are some sharp people on this forum.
Charlie
