Originally Posted by CindyM
Is it worth keeping/fixing or should I buy an inexpensive machine at walmart?
The feed dogs for the later T&S machines were flat with a rubbery coating - to handle slick fabrics better than toothy dogs. The rubber will disintegrate over time and rub off on your fabrics and it's the devil to get the stains out.
Terry at TNT Repair has replacement feed dogs in either the original rubbery stuff or the toothy type. He is THE source for all things slant - he will probably have anything you need to refurbish your 758 including a couple of books that he wrote himself. There are lots of pictures in them and they're easier for hobbyists to understand than most adjusters' manuals, which you will also need.
http://www.tandtrepair.com/index.html
I might take this on as a project machine just because it's fun to mess around with. But, I wouldn't pay much to have someone fix it. Maybe just have him put the bobbin case back in and time it and clean/oil it. If it sews well after that, you have a nice machine for $50.
It's going to be very expensive to get the gears replaced and who knows what else might be wrong with it. For the same amount of money, you can get a nice little Brother CS 6000t at Walmart.
If the bobbin case is already out, it could be that the gears were already crumbling and someone was trying to troubleshoot the problem.
It's normal for the bobbin to come apart - you unscrew them to remove what's left of the old thread on the bobbin before filling it with new thread. :)