Top guide for milguard window

Thanks for reaching out to us. That black guide you're referring to is a part of the hinge. We don't sell it separately, so you'll need a new hinge. Start by taking a look at the 36-004-10 and 36-004-14. We just recommend you replace the top and bottom hinges at the same time. Review the specifications and see how they compare with yours. 

DImensions for 36-004-10

Detailed view of the slider for 36-004-10

Dimensions for 36-004-14

Detailed view of the slider for 36-004-14