There's a post somewhere in the MX library that has the link to the Mr. Webman site that has the manual for download for free. But its easier for me to just post the site here:
http://mrwebman.com/aviation/cessna/manuals/
I downloaded my copies from there before they became available for free from the Textron Cessna site. I've since downloaded the ones from the Cessna site to see if they are different/more up to date, and I didn't see any material differences. (It's not like Cessna's been updating the manuals.) So I've continued to use the ones downloaded from Mr. Webman (without any problems).
But I do recommend that you sign up with Cessna to access the support section of their site. Its free (always a good thing). Then you can download (for free), not only the manuals, but the service bulletins, service letters, etc. (for free). That's the part that's really worth the price of admission. Plus, once you are signed up, you will receive a weekly service email from Cessna with links to any new service bulletins or other info about their aircraft. If you're lucky, one of them a year will have something related to the 170. But hey, you get to keep current on what's happening with the Citation fleet. (Actually, the emails are not a burden at all. In just a glance, you can see if they have anything to do with the 170.). One note of caution about using the site to download info for free. Previously, you had to pay for the manuals, etc. You can still do that on the site. So while using it, if you have to put the manuals, service bulletins, etc in a chechout basket on the site, you are doing the free download wrong. If i remember correctly, to download for free, once you log in, your aircraft info should appear (I think on the left), then you click on the 100 Series link on the left, then you choose from the menu on the right sidbar (that's the important part). Something like that. If I remember correctly, if you Initially search from the center screen, it will try to charge you. It's not the most intuitive, but you'll figure it out. I know that you can still download for free because I downloaded a service bulletin last week.
While you're at it, go to the Continental website and download the engine manuals. That's really easy though.
Seriously, if you have trouble figuring out the Cessna site, I can walk you through it better. I just need to go on it and remind myself how to access the free stuff.
I hope this helps.