Firm posted a teaser Pin last week prompting hundreds of followers to ask for details.
The Pin2Win competition asks Pinners to open a John Crane rainy day pin board and add John Crane toys, telling the public how they like to play with John Crane toys on a rainy day.
The social media savvy company is offering £150 worth of toys for the winning board, judged by John crane staff.
Marketing manager, Helen Davis said: "With all the bad weather we’ve been having, it seemed an obvious way to get parents showing other parents great toys for indoor play."
The competition encourages each Pinner to make their board using at least ten John Crane toys, plus any other rainy day activities they wish to pin, along with a description of how they play with each toy. All the link backs to www.john-crane.co.uk will ensure good SEO rankings and higher website traffic for the company.
Retailers can also join in and make their own John Crane Rainy Day Pinterest boards, as linking to the competition on Pinterest will grown their own audiences too.