Good news is that the shaft adapter has not changed so finding almost any used shaft with a Titleist driver adaptor will be a quick and easy fit. Trim to your liking or add a lengthening plug and install a new grip. With such an old club head model, probably not worth the cost to purchase a brand new shaft. You would be better off going and getting fit for the new TSR line with a new shaft as the combo would likely produce better results for you.

While Titleist concierge’s monitor this site, almost all the postings are by us biased end users.
Any pro shop or retailer that are authorized dealers can work with you to order a replacement shaft. I don’t know for certain that you can specify and order shafts from “My Titleist”.

The 917 is a 7 year old club. The replacement shaft maybe close to $150, maybe up to $100 more. See a dealer for pricing.

That’s at the high end of the retail value of a used 917 D2 driver. There is one on eBay a 917 D2 (8.5) with one bid under $20, 4 days to go. You can always buy that, swap shafts, and resell it. You might have to add an extender to the shaft for the length. But if the length creates too much off center hits, you can remove it.

With the added 1 inch length you’d need a lighter head weight to get the same swing weight as the stock length. Those would be available only as aftermarket online.

Recommend going to a Titleist account/fitter in your area and have them order one for you. I personally love the Fujikura Speeder shafts, have them on all my metals. Motores were my favorites and still have them on my 818 hybrids and TSI three wood.

You can order a new shaft through any Titleist retailer or golf shop. I would suggest that you work with a fitter to ensure the shaft brand and specs are correct for your game.