felt strip at top of sliding door yo ease opening and to take up the gap

Hello, 

We'd be happy to help you find some replacement weatherstripping. If you could send us a picture of the cross section of your weatherstripping and some dimensions, we will do our best to point you in the right direction.

Thank you!

I understand. Seeing some photos, similar to the diagram below, of your strip would help us recommend a part that would fill out your door and prevent it from wobbling. 

Thank you.

Example illustration of a cross section.