CAD Manager / Design Eng.
You may put in as Mechanical Drawing Drafter/Checker in the title and then list the duties as required.
As having been one, what's the reason for omitting "Administrator" from the title (you used the verb in your question)?
Also, as Mr. Gupta mentioned, list the position's requirements, but I'd suggest categorizing them as primary and secondary so applicants are clear on what's required.
What depth of PDM admin is required? Development? Only maintenance?
Is it a permanent position?
By which I mean, will someone what to move upward on the CAD side, as an engineer may be inclined?
Or do you want the person to maintain the admin role and the checking, etc are "filler" duties?
If the person's path doesn't match yours, you may be repeating this process sooner than you wanted.