A good site for tool parts and schematics. www.toolpartsdirect.com
In case you break a tool, they have many manufacturers lists. Another great tool for your shop.
I try to keep it simple, there are soooooo many sites out there. My favorites list is huge. I have to update it every once and a while.
Kind of like my tools.
I found that eReplacementParts.com has more parts and components available. They also have a super user friendly website with free videos and articles regarding tool repair. Check it out and you just found the only replacements parts website you will ever need to bookmark.