So, my 1986 300ZX N/A manual has a weird problem. There is never any play in the steering, and the alignment is straight, as in I can let go of the wheel and the car drives straight, but I find that sometimes I have to turn the wheel a few inches left to actually drive straight, and sometimes I have to turn it right. Mind you the alignment is still fine. What should I look at?

 

Tie rod ends at the very least. Perhaps a replacement steering rack.

 

Something is not right with your steering as you describe it. There should be a very small amount of play - maybe 1/2-inch or so - very little, but it is there. When you let go of the wheel at speed on a flat road, it should center out and go straight ahead, as you say. But there should never be any resistance to that so you have to 'correct' it by hand - and no way should it ever feel like anything is resisting free movement of the rack. Sounds like somebody over-repaired your steering for you. Definitely worth a complete check-up.

 

It is most likely the linkage in the column going into the rack. There are two points where the column has connections with U joints. I would absolutely check those..I had that play in my 280Zx years ago and also in my 88

 

OK, so I guess not everyone read my OP;

The alignment is fine. I can let go of the wheel and it drives "straight" but sometimes the wheel is not centered. It will still drive straight when the wheel is not centered.
There is NO play in the steering. It is very tight. I visually inspected the knuckle in the steering column and it looks fine. Driving straight sometimes requires the wheel not be centered, but I can still let go and drive straight

 

There are 2 links, as I said before. The top link may be worn. This is very similar to what I experienced.

 

That's the linkage you see when you take the cover off the steering wheel column right?

 

Negative! It is under the hood. Look at the column when you open the hood. As you follow it down you will see the two areas where the u joints connect the pieces of the column.
You can have some one turn the wheel very slightly..just nudging it side to side and you look for any play in the linkage. If the car is off, the wheel should be tight and very little play at all. If while the car is off and there is that play you describe...look at the linkage to see if you can see any play there. It should be tight. Obviously, there is some movement..but as you described, it is more than should be.

 

Obviously the alignment is not fine if the steering wheel is sometimes straight, sometimes not. Just because it drives straight, also doesn't mean there ISN'T an alignment problem.
Have you inspected the tires for abnormal wear?
Have you put the front end up and wobbled each tire in all directions?
I also suggest checking the alignment yourself (1001 YouTube "DIY Alignment" videos) or taking it to a shop that can diagnose the problem in 30 minutes.

 

A weird problem like that makes me think the steering rack itself is worn out. These can do what your describing about how the alignment is fine but the wheel moves. But check the steering linkage, get a friend and watch the linkage in the engine compartment as your friend turns the wheel back and forth.

 

Has the steering linkage been removed lately for some other repair? The splines on the rack input shaft are not indexed, the bottom u-joint can be installed in any position. If the steering was re-assembled with the u-joint off by only one spline, the steering wheel would not line up properly.

 

Alignment can easily be in spec and he could have this problem. It points to the issue being in the steering shaft upstream from the rack. Toe, camber, and caster are all that are adjusted in an alignment.

 

I'm with Donn144, check the steering column U joint universals. My 85 Turbo U joints went bad 15 years ago and my symptoms were similar to yours except in my case it was also harder to turn the wheel one way VS the other. Sisters 85NA had similar symptoms and it was the column U joints in that car too.

 

This is also a good sign of the rack bushings being worn. When they get neglected FOREVER, they get so bad that the rack will slide to the left when you turn right. then stay there, leaving the wheel crooked. then to turn left, the rack slides back to the right and the wheel is now crooked the other way. The car still drives straight however.

Hard to imagine that people bought these cars and didn't do any maintenance but this is one of those things that you come to find out with the more beat up examples. I highly Highly recommend getting the polurethane versions, and see about getting some fresh LCA and tension rods too. the car probably handles pretty bad.


EDIT.
Sorry this is an old post. I read it as 2016 not '15