I have the single handle type where you turn on left to right to go from Cold to Hot (shower). The cartridge is the single piece type. I did not have hot water in a shower that is rarely used. I tried using the Moen white plastic turning tool and it just broke off the plastic tabs on the cartridge. Just pulling it out was impossible as I would have ended up breaking the pipes, it was stuck in there so much. So, I made the extractor (attached photo), which worked very well. It simultaneously held the valve and pulled the cartridge. You can get everything you need at a hardware store to make this, print it and bring it with you. You will need a threaded dowel and the corresponding tap.

You just turn each threaded dowel and it pulls the cartridge since the threaded dowel ends are bottomed out on the valve housing; or adjust the threaded dowels and tighten down the screw and it will do the same.
http://i859.photobucket.com/albums/ab155/Noumenal1/MoenExt.jpg

Excellent! You've just invented a different version of a mechanics "wheel bearing puller".. I think it's a great idea.. necessity IS the mother of invention..

It probably cost less than the right tool. Moen Inc Cartridge Puller 104421 (http://www.google.com/products/catalog?hl=en&q=moen+cartridge+extractor&psj=1&wrapid=tlif12882308369721&um=1&ie=UTF-8&cid=7146018755885852126&ei=vNfITIb_KcT6lweKhOn2Ag&sa=X&oi=product_catalog_result&ct=result&resnum=1&ved=0CCoQ8wIwAA#) However, if you shop around you have to beat $9. http://www.google.com/products/catalog?hl=en&q=moen+cartridge+extractor&psj=1&wrapid=tlif12882308369721&um=1&ie=UTF-8&cid=13730212351628213303&ei=vNfITIb_KcT6lweKhOn2Ag&sa=X&oi=product_catalog_result&ct=result&resnum=3&ved=0CDAQ8wIwAg#

Hi guys...

This would've worked, too (see image), but that really is a great job you did there!

Tool is a Moen cartridge puller... :)

Thanks for posting your tool!

Mark

Hi Bob, (Ballengerb1)...I was posting when you were. I'll leave the pic. up for quick reference... ;)