It's easy to rebuild an Aries. Parts can be bought from the following nice lady -- I've talked with her a couple of times over the years. She's eager to help.
contact: Helen Franklin
address: 6 Dunvegan Road, Penryn, TR10 8HJ. UK.
phone: +44 (0)1326 377467
fax: +44 (0)1326 378117 email:[email protected]
I think she's the niece of the inventor, Nick Franklin. She's apparently got a garage full of spares. They're not cheap, but they are the original item.
The website is
Aries - Providing Vane Gear Spares. If you go to "Products" there is a link to "Rebuild Tips". It's not difficult to rebuild one yourself if you've got basic tools and a modicum of mechanical sense. From the "Products" page, surf around a bit until you find "How they work" -- there's an exploded parts diagram that will help you with the rebuild.
It sounds like you may have only to slightly readjust the gears. To do that you will need to take it apart, and once it's apart you might as well replace the parts that have worn. Helen sells a "rebuild kit" that has all of the parts that normally wear out.
Good luck -- if you have problems drop me a PM.