Ok, trying to get a handle on this. I've been reading and reading and reading on this forum on everything and learning so much, particularly on this subject. When turning at about 10 o'clock, or 2 o'clock, the steering really jumps at that point. It's almost like I can feel it starting to go, then it really goes. So much that when I'm cruising along on curves, I put both hands on the wheel so I don't end up in the ditch. New Cobra 255 60 15, at about 30 PSI, felt the same with the old Good Year Eagle GT II that were on it... I have heard of guys running them much lower PSI and it helps them a lot, haven't tried it, but it seems to me like the steering box. I checked it, it has grease, I even put a tad bit more play in it so it isn't as touchy and it did help it a bit, returning to center, but not much. Power steering fluid is full, Power steering assist cylinder appears fairly new, but has a "remanufactured" sticker on it (could this be part of the problem?). I do not know what the toe in or caster is, and that may be the whole issue. It drives smooth and fairly straight, does not wander around, turning at speed is the issue. Should I get it to a good Corvette alignment shop and check Caster and Toe in? It just seems very "darty". Trying to figure out where to start. I've read that having wider tires on these cars can be troublesome and I know mine needs some adjustment....somewhere, or many places.
Love my car and this forum, I haven't had it an entire year yet, but I learn so much here.

 

IF the steering box is not adjusted per the factory manual, it won't have the "feel" of center. Plus the added benefit of chewing up the internals. Other than adjusting the box, have you physically opened it up to look at the bushings and shaft?

 

I will re open and look closer, initially I was looking to see if it had grease or was dry.

 

Jim Shea has a set of papers to fully explain how to adjust the lash in the steering gear. Either on the car or on the bench.

http://jimshea.corvettefaq.com/