My car drifts slightly to the right if I don’t hold the steering wheel, and I always have to put a slight amount of pressure on it to keep it straight. It won’t just go straight down the road with no hands. After a little bit, it moves to the right. My mechanic suggested a front end alignment. Didn’t do much good. He then, gratis, did a rear end alignment. Not much better. And by a week or so later, the problem was back. What could be causing the problem? I fear it’s a steering linkage problem. Any ideas, dopers?
A dragging bearing or brake could cause it, but I would think the mechanic would have caught it.
Could be a bad tire too but I hope they checked that.
Perhaps the roads in your area are heavily crowned. All my vehicles take slight left pressure to track straight on major highways.
Low air pressure on the front right tire can cause the described problem.
In order to get a proper alignment, certain things must be checked and determined to be okay: steering linkage, suspension joints, and tire pressures. Presumably these items are in good order (if not it was a shoddy job).
Tire pull is often not detectable by visual inspection. It usually is determined by rotating tires to see if the pull changes.
Sometimes mechanics align with road crown in mind, and (if possible) adjust for a slight tendency to pull left to counterbalance road crown drift. However, different roads have different degree of crown, so it’s generally impossible to eliminate all drift. If the car goes a block without changing lane, I’d say that’s acceptable.
What bugs me most about your story is seeing some improvement, then regression. Assuming there was no impact against a curb or pothole, about the only thing that could change in that timeframe is a tire. Perhaps one has picked up a nail and is losing air fast enough to be a problem. A slipped belt that’s getting worse may also be a possibility.
The situation is very minor as you describe it. If the alignment is correct and the mechanic checked for wear on steering geometry, we have to consider other things. You could have a power steering rack that is tight on one side due to wear. It could happen to any model with that type steering, but GM had tons of problems that started with that symptom. Also, minor differences in tires can cause this. Move the tires around and recheck. If you still have the problem and it bothers you, then stagger the tire pressure. If it pulls to the right, keep less air in the left front tire by 2-4 pounds. That should bring it up to even. If not, I’m leaning toward the steering gear as a possible cause.
Is it weird that I saw the thread title and said, “What? Everything! You need Strength, Constitution, Dexterity, Wisdom, an’ a couple other stats, and that’s just the start!” 
Our ancient Camry pulled to the left. I had a good alignment shop go through it top to bottom and they finally concluded that it was tire pull.
Since I knew my front end wasn’t about to fall apart, I lived with it for a while until one day I replaced all the tires and the pull disappeared.
Interesting post, as my problem is with a '97 Camry. I’ll consult my files to find when I last had new tires put on, but it’s a good spot to look for solutions to the problem. Thanks. xo, C.