I'd like to replace the pivot shoe and the spring

Hello,

If you have Certainteed windows, we offer the 15-192 pivot shoe, which uses the S170 and S171 coil springs, along with the parts listed under the related items section of the 15-192 product page. Please note that some customers have reported that they needed to shave the front of the shoe down to install it in their window jamb. If so, the part would not be able to be returned once modifications are made. Thanks for posting. 

detail of 15-192